SPIRE INC, 10-K filed on 11/14/2025
Annual Report
v3.25.3
Document And Entity Information - USD ($)
 12 Months Ended
Sep. 30, 2025
Nov. 14, 2025
Mar. 31, 2025
Document Information [Line Items]      
Entity Central Index Key 0001126956    
Entity Registrant Name Spire Inc.    
Amendment Flag false    
Current Fiscal Year End Date --09-30    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2025    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Sep. 30, 2025    
Document Transition Report false    
Entity File Number 1-16681    
Entity Address, Address Line One 700 Market Street    
Entity Address, City or Town St. Louis    
Entity Address, State or Province MO    
Entity Address, Postal Zip Code 63101    
City Area Code 314    
Local Phone Number 342-0500    
Entity Incorporation, State or Country Code MO    
Entity Tax Identification Number 74-2976504    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 4,420,436,221
Entity Common Stock, Shares Outstanding   59,038,129  
Auditor Firm ID 34    
Auditor Name Deloitte & Touche LLP    
Auditor Location St. Louis, Missouri    
Spire Missouri [Member]      
Document Information [Line Items]      
Entity Central Index Key 0000057183    
Entity Registrant Name Spire Missouri Inc.    
Amendment Flag false    
Current Fiscal Year End Date --09-30    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2025    
Entity File Number 1-1822    
Entity Address, Address Line One 700 Market Street    
Entity Address, City or Town St. Louis    
Entity Address, State or Province MO    
Entity Address, Postal Zip Code 63101    
City Area Code 314    
Local Phone Number 342-0500    
Entity Incorporation, State or Country Code MO    
Entity Tax Identification Number 43-0368139    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   26,822  
Spire Alabama Inc [Member]      
Document Information [Line Items]      
Entity Central Index Key 0000003146    
Entity Registrant Name Spire Alabama Inc.    
Amendment Flag false    
Current Fiscal Year End Date --09-30    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2025    
Entity File Number 2-38960    
Entity Address, Address Line One 605 Richard Arrington Blvd N    
Entity Address, City or Town Birmingham    
Entity Address, State or Province AL    
Entity Address, Postal Zip Code 35203    
City Area Code 205    
Local Phone Number 326-8100    
Entity Incorporation, State or Country Code AL    
Entity Tax Identification Number 63-0022000    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   1,972,052  
Common Stock [Member]      
Document Information [Line Items]      
Title of 12(b) Security Common Stock $1.00 par value    
Trading Symbol SR    
Security Exchange Name NYSE    
Depositary Shares [Member]      
Document Information [Line Items]      
Title of 12(b) Security Depositary Shares    
Trading Symbol SR.PRA    
Security Exchange Name NYSE    
v3.25.3
Consolidated Statements of Income - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Operating Revenues $ 2,476.4 $ 2,593.0 $ 2,666.3
Operating Expenses:      
Natural gas 905.5 1,103.3 1,260.8
Operation and maintenance 542.1 507.4 517.6
Depreciation and amortization 298.2 278.4 254.8
Taxes, other than income taxes 206.7 215.6 214.5
Total Operating Expenses 1,952.5 2,104.7 2,247.7
Operating Income 523.9 488.3 418.6
Interest Expense 204.1 201.1 185.7
Other Income, Net 11.6 22.4 23.4
Income Before Income Taxes 331.4 309.6 256.3
Income Tax Expense 59.7 58.7 38.8
Net Income 271.7 250.9 217.5
Provision for preferred dividends 14.8 14.8 14.8
Income allocated to participating securities 0.3 0.3 0.3
Net Income Available to Common Shareholders $ 256.6 $ 235.8 $ 202.4
Weighted Average Number of Common Shares Outstanding:      
Basic (in shares) 58.5 56.1 52.5
Diluted (in shares) 58.7 56.3 52.6
Basic Earnings Per Share of Common Stock (in dollars per share) $ 4.39 $ 4.2 $ 3.86
Diluted Earnings Per Share of Common Stock (in dollars per share) $ 4.37 $ 4.19 $ 3.85
Spire Missouri [Member]      
Operating Revenues $ 1,544.1 $ 1,737.4 $ 1,762.9
Operating Expenses:      
Natural gas 669.4 886.2 943.4
Operation and maintenance 300.7 287.4 296.2
Depreciation and amortization 188.4 174.0 158.7
Taxes, other than income taxes 151.1 157.7 157.5
Total Operating Expenses 1,309.6 1,505.3 1,555.8
Operating Income 234.5 232.1 207.1
Interest Expense 100.2 106.4 97.4
Other Income, Net 7.8 8.4 19.4
Income Before Income Taxes 142.1 134.1 129.1
Income Tax Expense 13.8 15.7 11.6
Net Income 128.3 118.4 117.5
Spire Alabama Inc [Member]      
Operating Revenues 545.2 578.9 571.1
Operating Expenses:      
Natural gas 154.4 189.5 202.7
Operation and maintenance 137.1 135.6 136.4
Depreciation and amortization 71.0 72.8 69.3
Taxes, other than income taxes 40.2 42.7 43.0
Total Operating Expenses 402.7 440.6 451.4
Operating Income 142.5 138.3 119.7
Interest Expense 29.6 33.1 34.9
Other Income, Net 0.4 1.8 1.5
Income Before Income Taxes 113.3 107.0 86.3
Income Tax Expense 28.4 26.9 20.3
Net Income $ 84.9 $ 80.1 $ 66.0
v3.25.3
Consolidated Statements of Comprehensive Income - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Net Income (Loss) $ 271.7 $ 250.9 $ 217.5
Other Comprehensive Income (Loss), Before Tax:      
Net hedging gain (loss) arising during the period 12.8 (15.9) 20.1
Amounts reclassified into regulatory liabilities 0.0 (20.1) (17.5)
Amounts reclassified into net income (5.1) (11.1) (2.4)
Net gain (loss) on cash flow hedging derivative instruments 7.7 (47.1) 0.2
Net gain on defined benefit pension and other postretirement plans 1.3 0.6 0.2
Net unrealized gain on available-for-sale debt securities 0.1 0.2 0.1
Other Comprehensive Income (Loss), Before Tax 9.1 (46.3) 0.5
Income Tax Expense (Benefit) Related to Items of Other Comprehensive Income 1.8 (10.8) 0.1
Other Comprehensive Income (Loss), Net of Tax 7.3 (35.5) 0.4
Comprehensive Income 279.0 215.4 217.9
Operating Revenues 2,476.4 2,593.0 2,666.3
Operating Expenses:      
Natural gas 905.5 1,103.3 1,260.8
Operation and maintenance 542.1 507.4 517.6
Depreciation and amortization expense 298.2 278.4 254.8
Taxes, other than income taxes 206.7 215.6 214.5
Total Operating Expenses 1,952.5 2,104.7 2,247.7
Operating Income 523.9 488.3 418.6
Interest Expense 204.1 201.1 185.7
Other Income, Net 11.6 22.4 23.4
Income Before Income Taxes 331.4 309.6 256.3
Income Tax Expense 59.7 58.7 38.8
Net Income 271.7 250.9 217.5
Spire Missouri [Member]      
Net Income (Loss) 128.3 118.4 117.5
Other Comprehensive Income (Loss), Before Tax:      
Other Comprehensive Income (Loss), Net of Tax 1.3 0.5 0.2
Comprehensive Income 129.6 118.9 117.7
Operating Revenues 1,544.1 1,737.4 1,762.9
Operating Expenses:      
Natural gas 669.4 886.2 943.4
Operation and maintenance 300.7 287.4 296.2
Depreciation and amortization expense 188.4 174.0 158.7
Taxes, other than income taxes 151.1 157.7 157.5
Total Operating Expenses 1,309.6 1,505.3 1,555.8
Operating Income 234.5 232.1 207.1
Interest Expense 100.2 106.4 97.4
Other Income, Net 7.8 8.4 19.4
Income Before Income Taxes 142.1 134.1 129.1
Income Tax Expense 13.8 15.7 11.6
Net Income $ 128.3 $ 118.4 $ 117.5
v3.25.3
Consolidated Balance Sheets - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
ASSETS    
Utility Plant $ 9,333.9 $ 8,779.1
Less: Accumulated depreciation and amortization 2,577.4 2,535.8
Net Utility Plant 6,756.5 6,243.3
Non-utility Property (net of accumulated depreciation and amortization of $129.4 and $96.8 at September 30, 2025 and 2024, respectively) 1,007.2 955.3
Other Investments 128.0 115.3
Total Other Property and Investments 1,135.2 1,070.6
Current Assets:    
Cash and cash equivalents 5.7 4.5
Accounts receivable:    
Utility 191.9 196.3
Other 152.7 112.5
Allowance for credit losses (28.8) (31.4)
Delayed customer billings 13.6 12.0
Inventories:    
Natural gas 226.9 208.6
Propane gas 8.6 8.6
Materials and supplies 47.0 46.7
Regulatory Assets, Current 78.3 115.4
Prepayments 47.8 47.6
Other 64.0 50.5
Total Current Assets 807.7 771.3
Deferred Charges and Other Assets:    
Goodwill 1,171.6 1,171.6
Regulatory assets 1,323.5 1,251.8
Other 380.8 352.1
Total Deferred Charges and Other Assets 2,875.9 2,775.5
Total Assets 11,575.3 10,860.7
Capitalization:    
Common stock 59.0 57.7
Paid-in capital 1,981.4 1,902.2
Retained earnings 1,087.6 1,018.7
Accumulated other comprehensive income 19.4 12.1
Total Shareholders' Equity 3,389.4 3,232.7
Temporary equity 6.1 8.6
Long-term debt (less current portion) 3,369.4 3,704.4
Total Capitalization 6,764.9 6,945.7
Current Liabilities:    
Current portion of long-term debt 487.5 42.0
Notes payable 1,317.0 947.0
Accounts payable 248.3 237.2
Advance customer billings 58.1 48.4
Wages and compensation accrued 54.1 51.5
Customer deposits 32.8 29.9
Taxes accrued 109.1 105.2
Regulatory liabilities 39.4 49.5
Other 202.3 193.2
Total Current Liabilities 2,548.6 1,703.9
Deferred Credits and Other Liabilities:    
Deferred income taxes 887.4 808.4
Pension and postretirement benefit costs 74.7 146.7
Asset retirement obligations 583.2 579.9
Regulatory liabilities 578.0 535.5
Other 138.5 140.6
Total Deferred Credits and Other Liabilities 2,261.8 2,211.1
Commitments and Contingencies (Note 16)
Total Capitalization and Liabilities 11,575.3 10,860.7
Depositary Shares [Member]    
Capitalization:    
Preferred stock ($25.00 par value per share; 10.0 million depositary shares authorized, issued and outstanding at September 30, 2025 and 2024) 242.0 242.0
Spire Missouri [Member]    
ASSETS    
Utility Plant 5,864.3 5,420.2
Less: Accumulated depreciation and amortization 1,104.6 1,086.0
Net Utility Plant 4,759.7 4,334.2
Total Other Property and Investments 75.8 70.1
Accounts receivable:    
Other 34.0 22.2
Allowance for credit losses (23.0) (24.9)
Delayed customer billings 4.2 5.7
Inventories:    
Natural gas 150.0 129.6
Propane gas 8.6 8.6
Materials and supplies 24.5 24.4
Regulatory Assets, Current 48.9 84.0
Prepayments 28.2 27.2
Total Current Assets 426.7 432.5
Deferred Charges and Other Assets:    
Goodwill 210.2 210.2
Regulatory assets 653.2 588.0
Other 224.2 193.6
Total Deferred Charges and Other Assets 1,087.6 991.8
Total Assets 6,349.8 5,828.6
Capitalization:    
Common stock 0.1 0.1
Paid-in capital 929.2 854.8
Retained earnings 1,239.1 1,110.8
Accumulated other comprehensive income (0.7) (2.0)
Total Shareholders' Equity 2,167.7 1,963.7
Long-term debt (less current portion) 1,953.6 1,803.4
Total Capitalization 4,121.3 3,767.1
Current Liabilities:    
Advance customer billings 43.2 35.5
Wages and compensation accrued 27.0 24.2
Customer deposits 7.2 6.1
Taxes accrued 65.8 60.2
Regulatory liabilities 13.9 10.2
Other 64.3 50.6
Total Current Liabilities 908.0 781.7
Deferred Credits and Other Liabilities:    
Deferred income taxes 598.7 567.6
Pension and postretirement benefit costs 72.4 110.0
Asset retirement obligations 95.5 95.7
Regulatory liabilities 481.3 443.3
Other 72.6 63.2
Total Deferred Credits and Other Liabilities 1,320.5 1,279.8
Commitments and Contingencies (Note 16)
Total Capitalization and Liabilities 6,349.8 5,828.6
Spire Missouri [Member] | Nonrelated Party [Member]    
Accounts receivable:    
Utility 149.1 152.9
Current Liabilities:    
Accounts payable 98.9 92.0
Spire Missouri [Member] | Related Party [Member]    
Accounts receivable:    
Utility 2.2 2.8
Current Liabilities:    
Notes payable 566.3 495.3
Accounts payable 21.4 7.6
Spire Alabama Inc [Member]    
ASSETS    
Utility Plant 3,052.9 2,966.6
Less: Accumulated depreciation and amortization 1,362.4 1,336.6
Net Utility Plant 1,690.5 1,630.0
Total Other Property and Investments 0.1 0.1
Current Assets:    
Cash and cash equivalents 1.9 1.5
Accounts receivable:    
Other 6.9 6.1
Allowance for credit losses (4.9) (5.7)
Delayed customer billings 9.0 5.7
Inventories:    
Natural gas 39.4 37.3
Materials and supplies 19.0 18.7
Regulatory Assets, Current 16.1 19.2
Prepayments 7.7 10.7
Total Current Assets 129.9 129.4
Deferred Charges and Other Assets:    
Regulatory assets 650.6 642.0
Other 99.2 94.8
Total Deferred Charges and Other Assets 749.8 736.8
Total Assets 2,570.3 2,496.3
Capitalization:    
Retained earnings 735.2 668.9
Total Shareholders' Equity 978.1 948.3
Long-term debt (less current portion) 711.7 711.3
Total Capitalization 1,689.8 1,659.6
Common stock and paid-in capital (par value $0.01 per share; 3,000,000 shares authorized; 1,972,052 issued and outstanding at September 30, 2025 and 2024) 242.9 279.4
Current Liabilities:    
Current portion of long-term debt 0.0 35.0
Advance customer billings 13.1 10.9
Wages and compensation accrued 7.8 7.2
Customer deposits 22.3 20.8
Taxes accrued 33.1 34.8
Regulatory liabilities 20.3 33.8
Other 14.6 13.8
Total Current Liabilities 290.0 249.4
Deferred Credits and Other Liabilities:    
Deferred income taxes 64.1 35.9
Pension and postretirement benefit costs 2.4 28.0
Asset retirement obligations 470.0 468.6
Regulatory liabilities 29.2 28.3
Other 24.8 26.5
Total Deferred Credits and Other Liabilities 590.5 587.3
Commitments and Contingencies (Note 16)
Total Capitalization and Liabilities 2,570.3 2,496.3
Spire Alabama Inc [Member] | Nonrelated Party [Member]    
Accounts receivable:    
Utility 34.8 35.5
Current Liabilities:    
Accounts payable 43.3 38.0
Spire Alabama Inc [Member] | Related Party [Member]    
Accounts receivable:    
Utility 0.0 0.4
Current Liabilities:    
Notes payable 130.1 48.4
Accounts payable $ 5.4 $ 6.7
v3.25.3
Consolidated Balance Sheets (Parentheticals) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Non-utility property, accumulated depreciation and amortization $ 129.4 $ 96.8
Preferred stock, shares authorized (in shares) 5,000,000 5,000,000
Common stock, par value (in dollars per share) $ 1 $ 1
Common stock, shares authorized (in shares) 70,000,000 70,000,000
Common stock, shares issued (in shares) 59,000,000 57,700,000
Common stock, shares outstanding (in shares) 59,000,000 57,700,000
Spire Missouri [Member]    
Preferred stock, shares authorized (in shares) 1,480,000 1,480,000
Preferred stock, shares issued (in shares) 0 0
Common stock, par value (in dollars per share) $ 1 $ 1
Common stock, shares authorized (in shares) 50,000,000 50,000,000
Common stock, shares issued (in shares) 26,822 26,822
Common stock, shares outstanding (in shares) 25,855 25,855
Spire Alabama Inc [Member]    
Preferred stock, shares authorized (in shares) 120,000 120,000
Preferred stock, shares issued (in shares) 0 0
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, shares authorized (in shares) 3,000,000 3,000,000
Common stock, shares issued (in shares) 1,972,052 1,972,052
Common stock, shares outstanding (in shares) 1,972,052 1,972,052
Depositary Shares [Member]    
Preferred stock, par value (in dollars per share) $ 25 $ 25
Preferred stock, shares authorized (in shares) 10,000,000 10,000,000
Preferred stock, shares issued (in shares) 10,000,000 10,000,000
Preferred stock, shares outstanding (in shares) 10,000,000 10,000,000
v3.25.3
Consolidated Statements of Shareholders' Equity - USD ($)
$ in Millions
Total
Common Stock [Member]
Preferred Stock [Member]
Additional Paid-in Capital [Member]
Retained Earnings [Member]
AOCI Attributable to Parent [Member]
Spire Missouri [Member]
Spire Missouri [Member]
Common Stock [Member]
Spire Missouri [Member]
Additional Paid-in Capital [Member]
Spire Missouri [Member]
Retained Earnings [Member]
Spire Missouri [Member]
AOCI Attributable to Parent [Member]
Spire Alabama Inc [Member]
Spire Alabama Inc [Member]
Common Stock [Member]
Spire Alabama Inc [Member]
Additional Paid-in Capital [Member]
Spire Alabama Inc [Member]
Retained Earnings [Member]
Balance (in shares) at Sep. 30, 2022   52,494,543           25,325         1,972,052    
Balance at Sep. 30, 2022 $ 2,818.5 $ 52.5 $ 242.0 $ 1,571.3 $ 905.5 $ 47.2 $ 1,745.4 $ 0.1 $ 816.1 $ 931.9 $ (2.7) $ 906.0   $ 316.9 $ 589.1
Net Income (Loss) 217.5       217.5   117.5     117.5   66.0     66.0
Common stock issued (in shares)   611,872           530              
Common stock issued 40.5 $ 0.6   39.9     38.7   38.7            
Dividend reinvestment plan (in shares)   22,230                          
Dividend reinvestment plan 1.5     1.5                      
Stock-based compensation costs 5.3     5.3                      
Stock issued under stock-based compensation plans (in shares)   60,007                          
Stock issued under stock-based compensation plans   $ 0.1   (0.1)                      
Employees’ tax withholding for stock-based compensation (in shares)   (18,428)                          
Employees’ tax withholding for stock-based compensation (1.4)     (1.4)                      
Common stock, dividends (152.5)       (152.5)   (57.0)     (57.0)   (13.0)     (13.0)
Preferred stock, dividends (14.8)       (14.8)                    
Other Comprehensive Income, Net of Tax 0.4         0.4 0.2       0.2        
Temporary equity adjustment to redemption value 2.3       2.3                    
Employees’ tax withholding for stock-based compensation (in shares)   18,428                          
Employees’ tax withholding for stock-based compensation 1.4     1.4                      
Return of capital to Spire                       (31.0)   (31.0)  
Balance (in shares) at Sep. 30, 2023   53,170,224           25,855         1,972,052    
Balance at Sep. 30, 2023 2,917.3 $ 53.2 242.0 1,616.5 958.0 47.6 1,844.8 $ 0.1 854.8 992.4 (2.5) 928.0   285.9 642.1
Net Income (Loss) 250.9       250.9   118.4     118.4   80.1     80.1
Common stock issued (in shares)   4,490,282                          
Common stock issued 285.3 $ 4.4   280.9                      
Dividend reinvestment plan (in shares)   26,041                          
Dividend reinvestment plan 1.5     1.5                      
Stock-based compensation costs 4.8     4.8                      
Stock issued under stock-based compensation plans (in shares)   87,844                          
Stock issued under stock-based compensation plans   $ 0.1   (0.1)                      
Employees’ tax withholding for stock-based compensation (in shares)   (24,724)                          
Employees’ tax withholding for stock-based compensation (1.4)     (1.4)                      
Common stock, dividends (172.9)       (172.9)             (53.3)     (53.3)
Preferred stock, dividends (14.8)       (14.8)                    
Other Comprehensive Income, Net of Tax (35.5)         (35.5) 0.5       0.5        
Temporary equity adjustment to redemption value (2.5)       (2.5)                    
Employees’ tax withholding for stock-based compensation (in shares)   24,724                          
Employees’ tax withholding for stock-based compensation 1.4     1.4                      
Return of capital to Spire                       (6.5)   (6.5)  
Balance (in shares) at Sep. 30, 2024   57,749,667           25,855         1,972,052    
Balance at Sep. 30, 2024 3,232.7 $ 57.7 242.0 1,902.2 1,018.7 12.1 1,963.7 $ 0.1 854.8 1,110.8 (2.0) 948.3   279.4 668.9
Net Income (Loss) 271.7       271.7   128.3     128.3   84.9     84.9
Common stock issued (in shares)   1,206,134           967              
Common stock issued 74.7 $ 1.2   73.5     74.4   74.4            
Dividend reinvestment plan (in shares)   22,006                          
Dividend reinvestment plan 1.5     1.5                      
Stock-based compensation costs 6.1     6.1                      
Stock issued under stock-based compensation plans (in shares)   73,471                          
Stock issued under stock-based compensation plans   $ 0.1   (0.1)                      
Employees’ tax withholding for stock-based compensation (in shares)   (25,317)                          
Employees’ tax withholding for stock-based compensation (1.8)     (1.8)                      
Common stock, dividends (185.2)       (185.2)             (18.6)     (18.6)
Preferred stock, dividends (14.8)       (14.8)                    
Other Comprehensive Income, Net of Tax 7.3         7.3 1.3       1.3        
Temporary equity adjustment to redemption value (2.8)       (2.8)                    
Employees’ tax withholding for stock-based compensation (in shares)   25,317                          
Employees’ tax withholding for stock-based compensation 1.8     1.8                      
Return of capital to Spire                       (36.5)   (36.5)  
Balance (in shares) at Sep. 30, 2025   59,025,961           26,822         1,972,052    
Balance at Sep. 30, 2025 $ 3,389.4 $ 59.0 $ 242.0 $ 1,981.4 $ 1,087.6 $ 19.4 $ 2,167.7 $ 0.1 $ 929.2 $ 1,239.1 $ (0.7) $ 978.1   $ 242.9 $ 735.2
v3.25.3
Consolidated Statements of Shareholders' Equity (Parentheticals) - $ / shares
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Common stock, dividends per share declared (in dollars per share) $ 3.14 $ 3.02 $ 2.88
Preferred stock dividends per share declared (in dollars per share) $ 1.475 $ 1.475 $ 1.475
v3.25.3
Consolidated Statements of Cash Flows - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Operating Activities:      
Net Income (Loss) $ 271.7 $ 250.9 $ 217.5
Adjustments to reconcile net income to net cash provided by operating activities:      
Depreciation and amortization 298.2 278.4 254.8
Deferred income taxes and investment tax credits 57.3 57.0 36.9
Changes in assets and liabilities:      
Accounts receivable (38.4) 12.7 334.2
Inventories (18.6) 15.8 142.8
Regulatory assets and liabilities 26.5 341.4 (68.7)
Accounts payable 47.5 (25.1) (389.2)
Delayed/advance customer billings, net 8.1 37.5 1.5
Taxes accrued 6.0 1.1 15.0
Other assets and liabilities (93.4) (65.6) (117.6)
Other 13.1 8.3 13.0
Net cash provided by operating activities 578.0 912.4 440.2
Investing Activities:      
Capital expenditures (922.4) (861.3) (662.5)
Business acquisition, net of cash acquired 0.0 (175.9) (37.0)
Other 6.0 10.0 4.0
Net cash used in investing activities (916.4) (1,027.2) (695.5)
Financing Activities:      
Issuance of long-term debt 150.0 495.0 755.0
Repayment of long-term debt (42.0) (456.6) (281.2)
Issuance (repayment) of short-term debt, net 370.0 (8.5) (82.0)
Issuance of common stock 76.2 287.0 41.9
Dividends paid on common stock (182.2) (167.1) (150.7)
Dividends paid on preferred stock (14.8) (14.8) (14.8)
Other (12.5) (11.1) (7.6)
Net cash provided by (used in) financing activities 344.7 123.9 260.6
Net Increase (Decrease) in Cash and Cash Equivalents 6.3 9.1 5.3
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year 34.9 25.8 20.5
Cash, Cash Equivalents, and Restricted Cash at End of Year 41.2 34.9 25.8
Supplemental disclosure of cash paid for:      
Interest, net of amounts capitalized (207.1) (205.6) (177.5)
Income taxes (2.9) (0.9) (2.0)
Spire Missouri [Member]      
Operating Activities:      
Net Income (Loss) 128.3 118.4 117.5
Adjustments to reconcile net income to net cash provided by operating activities:      
Depreciation and amortization 188.4 174.0 158.7
Deferred income taxes and investment tax credits 13.6 14.8 11.6
Changes in assets and liabilities:      
Accounts receivable (9.3) (14.2) 16.0
Inventories (20.5) 3.0 80.2
Regulatory assets and liabilities 22.0 310.8 (22.4)
Accounts payable 28.6 (5.3) (45.7)
Delayed/advance customer billings, net 9.2 36.7 2.2
Taxes accrued 5.9 0.1 9.7
Other assets and liabilities (25.2) (65.2) (108.4)
Other 2.7 1.4 1.7
Net cash provided by operating activities 343.7 574.5 221.1
Investing Activities:      
Capital expenditures (641.2) (553.0) (447.5)
Other 4.5 6.7 4.1
Net cash used in investing activities (636.7) (546.3) (443.4)
Financing Activities:      
Issuance of long-term debt 150.0 320.0 400.0
Repayment of long-term debt 0.0 (300.0) (250.0)
Borrowings (repayments to) from Spire, net 71.0 (45.3) 95.3
Issuance of common stock 74.4 0.0 38.7
Dividends paid on common stock 0.0 0.0 (57.0)
Other (2.4) (3.7) (3.9)
Net cash provided by (used in) financing activities 293.0 (29.0) 223.1
Net Increase (Decrease) in Cash and Cash Equivalents 0.0 (0.8) 0.8
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year 0.0 0.8 0.0
Cash, Cash Equivalents, and Restricted Cash at End of Year 0.0 0.0 0.8
Supplemental disclosure of cash paid for:      
Interest, net of amounts capitalized (102.9) (111.6) (93.8)
Income taxes (0.9) (0.4) (0.2)
Spire Alabama Inc [Member]      
Operating Activities:      
Net Income (Loss) 84.9 80.1 66.0
Adjustments to reconcile net income to net cash provided by operating activities:      
Depreciation and amortization 71.0 72.8 69.3
Deferred income taxes and investment tax credits 28.4 26.9 20.3
Changes in assets and liabilities:      
Accounts receivable (0.5) 8.0 27.1
Inventories (2.4) 15.6 17.2
Regulatory assets and liabilities 2.7 49.3 (49.5)
Accounts payable 8.8 2.4 (42.3)
Delayed/advance customer billings, net (1.1) 0.7 (0.6)
Taxes accrued (1.7) 0.3 3.3
Other assets and liabilities (38.5) (8.6) 18.7
Other 0.9 0.4 0.4
Net cash provided by operating activities 152.5 247.9 129.9
Investing Activities:      
Capital expenditures (144.2) (112.8) (117.6)
Other 0.9 0.8 1.3
Net cash used in investing activities (143.3) (112.0) (116.3)
Financing Activities:      
Issuance of long-term debt 0.0 0.0 175.0
Repayment of long-term debt (35.0) 0.0 0.0
Borrowings (repayments to) from Spire, net 81.7 (75.7) (136.8)
Return of capital to Spire (36.5) (6.5) (31.0)
Dividends paid on common stock (18.6) (53.4) (21.0)
Other (0.4) 0.0 (1.0)
Net cash provided by (used in) financing activities (8.8) (135.6) (14.8)
Net Increase (Decrease) in Cash and Cash Equivalents 0.4 0.3 (1.2)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year 1.5 1.2 2.4
Cash, Cash Equivalents, and Restricted Cash at End of Year 1.9 1.5 1.2
Supplemental disclosure of cash paid for:      
Interest, net of amounts capitalized (28.9) (32.9) (30.1)
Income taxes $ 0.0 $ 0.0 $ 0.0
v3.25.3
Cybersecurity Risk Management, Strategy, and Governance
 12 Months Ended
Sep. 30, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]

Item 1C. Cybersecurity

Managing risk related to cybersecurity is a top priority for Spire, and the Company remains focused on addressing threats that would jeopardize the confidentiality, integrity and availability of stakeholders’ information or the ability to continue providing safe and reliable service to customers. To date, Spire has not experienced any material cybersecurity breach that impacts the Company’s business strategy, results of operations, or financial condition.

Risk Management

Enterprise risk management ("ERM") at Spire oversees significant risks to the Company’s ability to successfully execute on strategy and achieve corporate objectives. Spire’s ERM is based on a structured, comprehensive process that leverages ISO 31000:2018, adopted and customized to the Company’s needs, utilizing an ongoing process of risk identification, evaluation, treatment, integration and monitoring. ERM helps assess priorities and facilitate decision-making for resource allocation as it relates to risk management. Two risks prioritized by our Enterprise Risk Oversight Committee related to cybersecurity are cyber threats and vendor management. Additionally, the ERM process is structured to integrate with operational levels, where risk is managed, such as the National Institute of Standards and Technology ("NIST") Cybersecurity Framework 2.0 utilized by the Company’s Information Security function for managing cybersecurity.

Governance

Spire’s Board of Directors (“Board”) recognizes the significance of cybersecurity risk and has therefore retained oversight of cybersecurity rather than delegating this risk to a committee of the Board. Every regular meeting of the Board includes a cybersecurity report provided by the Company’s Chief Information Officer and the Chief Information Security Officer. These reports focus on developments within the Company’s cybersecurity program and provide an update on any cybersecurity events or concerns. In 2024, the Board added a new director with expertise in cybersecurity to assist the Board to appropriately oversee the Company’s efforts.

Spire’s cybersecurity program is led by the Chief Information Officer and the Chief Information Security Officer, who together have over 40 years of experience in information technology and cybersecurity, along with a cross-functional team of technology, legal, physical security and risk leaders. Internal Audit provides assurances of risk management activities, including certain third-party cybersecurity activities, such as penetration testing.

Strategy/Approach

Spire’s cybersecurity team developed a five-year strategic roadmap in 2020, which is reviewed and updated annually. A NIST-based maturity assessment is also conducted annually to assess Spire’s current maturity level and is used to establish initiatives to drive capabilities in key focus areas. Such initiatives were updated to align with federal security directives issued in 2021, with a key focus on increasing overall visibility into the environment to better correlate potential security related items; completing segregation and dependency from the enterprise and industrial control systems environments; and establishing defined policies and procedures to enhance overall governance and risk management.

In addition to these strategic efforts, the Company works closely with federal agencies, including the U.S Department of Homeland Security, TSA and the local FBI chapter, and is actively involved in industry information sharing groups.

The Company’s cybersecurity function is staffed with dedicated professionals who continuously monitor risks and evaluate the resiliency and effectiveness of the architecture and defenses within Spire’s systems. The Company also maintains policies, procedures and standards to manage conduct within Spire and to be prepared for new cybersecurity threats and events. The cybersecurity program involves a variety of training and education to increase awareness of cybersecurity threats through mandatory annual security awareness training for all employees, quarterly phishing campaigns, and table-top exercises. The Company also engages third parties to evaluate potential risks through external penetration testing to assess the efficacy of systems.

Spire maintains business continuity plans to guide the Company’s response to a potential cybersecurity event. These plans are regularly reviewed, tested and updated to ensure they meet the evolving needs of the Company in this area. The Company also conducts annual disaster recovery exercises to test the efficacy of core systems in the event of a catastrophic incident.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block] Enterprise risk management ("ERM") at Spire oversees significant risks to the Company’s ability to successfully execute on strategy and achieve corporate objectives. Spire’s ERM is based on a structured, comprehensive process that leverages ISO 31000:2018, adopted and customized to the Company’s needs, utilizing an ongoing process of risk identification, evaluation, treatment, integration and monitoring.
Cybersecurity Risk Management Third Party Engaged [Flag] true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Board of Directors Oversight [Text Block]

Governance

Spire’s Board of Directors (“Board”) recognizes the significance of cybersecurity risk and has therefore retained oversight of cybersecurity rather than delegating this risk to a committee of the Board. Every regular meeting of the Board includes a cybersecurity report provided by the Company’s Chief Information Officer and the Chief Information Security Officer. These reports focus on developments within the Company’s cybersecurity program and provide an update on any cybersecurity events or concerns. In 2024, the Board added a new director with expertise in cybersecurity to assist the Board to appropriately oversee the Company’s efforts.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] Spire’s Board of Directors (“Board”) recognizes the significance of cybersecurity risk and has therefore retained oversight of cybersecurity rather than delegating this risk to a committee of the Board
Cybersecurity Risk Role of Management [Text Block] Spire’s cybersecurity program is led by the Chief Information Officer and the Chief Information Security Officer, who together have over 40 years of experience in information technology and cybersecurity, along with a cross-functional team of technology, legal, physical security and risk leaders. The Company’s cybersecurity function is staffed with dedicated professionals who continuously monitor risks and evaluate the resiliency and effectiveness of the architecture and defenses within Spire’s systems.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block] Spire’s cybersecurity program is led by the Chief Information Officer and the Chief Information Security Officer,
Cybersecurity Risk Management Expertise of Management Responsible [Text Block] who together have over 40 years of experience in information technology and cybersecurity, along with a cross-functional team of technology, legal, physical security and risk leaders.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] The Company’s cybersecurity function is staffed with dedicated professionals who continuously monitor risks and evaluate the resiliency and effectiveness of the architecture and defenses within Spire’s systems.
v3.25.3
Pay vs Performance Disclosure - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Pay vs Performance Disclosure      
Net Income (Loss) $ 271.7 $ 250.9 $ 217.5
v3.25.3
Insider Trading Arrangements
 3 Months Ended
Sep. 30, 2025
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.3
Insider Trading Policies and Procedures
 12 Months Ended
Sep. 30, 2025
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.3
Summary of Significant Accounting Policies
 12 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

BASIS OF PRESENTATION – These notes are an integral part of the accompanying audited financial statements of Spire Inc. (“Spire” or the “Company”) presented on a consolidated basis, Spire Missouri Inc. (“Spire Missouri”) and Spire Alabama Inc. (“Spire Alabama”). Spire Missouri, Spire Alabama and Spire EnergySouth Inc. (“Spire EnergySouth”) are wholly owned subsidiaries of Spire. Spire Missouri, Spire Alabama and the subsidiaries of Spire EnergySouth (Spire Gulf Inc. and Spire Mississippi Inc.) are collectively referred to as the “Utilities.” Unless otherwise indicated, references to years herein are references to the fiscal years ending September 30 for the Company and its subsidiaries.

The accompanying audited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The consolidated financial position, results of operations and cash flows of Spire include the accounts of the Company and all its subsidiaries. Transactions and balances between consolidated entities have been eliminated from the consolidated financial statements of Spire. In compliance with GAAP, transactions between Spire Missouri and Spire Alabama and their affiliates, as well as intercompany balances on their balance sheets, have not been eliminated from their separate financial statements.

NATURE OF OPERATIONS – Spire has three reportable segments: Gas Utility, Gas Marketing, and Midstream. The Gas Utility segment consists of the regulated natural gas distribution operations of the Company and is the core business segment of Spire in terms of revenue and earnings. The Gas Utility segment is comprised of the operations of: Spire Missouri, serving St. Louis, Kansas City, and other areas in Missouri; Spire Alabama, serving central and northern Alabama; and the subsidiaries of Spire EnergySouth, serving the Mobile, Alabama area and south-central Mississippi. The Gas Marketing segment includes Spire’s largest gas-related business, Spire Marketing Inc. (“Spire Marketing”), which provides non-regulated natural gas services throughout the United States (U.S.). The Midstream segment includes Spire Storage, Spire STL Pipeline and Spire MoGas Pipeline, which are subsidiaries engaged in the storage and transportation of natural gas. The activities of the Company’s other subsidiaries are reported as Other and are described in Note 14, Segment Information. Spire Missouri and Spire Alabama each have a single reportable segment.

USE OF ESTIMATES – The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.

SYSTEM OF ACCOUNTS – The accounts of the Utilities are maintained in accordance with the Uniform System of Accounts prescribed by the applicable state public service commissions, which systems substantially conform to those prescribed by FERC.

REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 980, Regulated Operations. This topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. See additional discussion of regulated operations in Note 15, Regulatory Matters.

PROPERTY, PLANT, AND EQUIPMENT –

Utility Plant – Utility plant is comprised primarily of our utility distribution assets and amounts are stated at original cost. The cost of additions to utility plant includes contracted work, direct labor and materials, allocable overheads and an allowance for funds used during construction. The costs of units of property retired, replaced or renewed are removed from utility plant and are charged to accumulated depreciation. Maintenance and repairs of property and replacement and renewal of items determined to be less than units of property are charged to maintenance expenses. Utility plant includes $268.3 and $143.2 of construction work-in-process ("CWIP") for 2025 and 2024, respectively.

Utility plant is depreciated using the composite method on a straight-line basis over the estimated service lives of the various classes of property at rates approved by the applicable regulatory commission. For Spire Missouri and for Spire Alabama, the annual depreciation and amortization expense in fiscal years 2025, 2024 and 2023 averaged approximately 3% of the original cost of depreciable and amortizable property.

Non-utility Property – Non-utility property is comprised primarily of our storage facilities, transportation pipelines and other assets. These assets are recorded at the original cost of acquisition or construction, which includes material, labor, contractor services and, for FERC-regulated projects, an allowance for funds used during construction. Repairs, replacements and renewals of items of property determined to be less than a unit of property or that do not increase the property’s life or functionality are charged to maintenance expense. Upon retirement or sale of non-utility property, the original cost and related accumulated depreciation are removed from the accounts and any gain or loss is included in the income statements. Costs related to software developed or obtained for internal use are capitalized and amortized on a straight-line basis over the estimated useful life of the related software. If software is retired prior to being fully amortized, the difference is recorded as a loss in the income statements unless the unamortized balance is expected to be recovered through a regulatory deferral mechanism. Depreciation expense for non-utility property is recorded straight-line over the life of the asset. Depreciation expense for non-utility property was $32.7, $25.8, and $20.6 for 2025, 2024, and 2023, respectively. Non-utility property is as follows:

 

 

 

2025

 

 

2024

 

Storage

 

$

453.8

 

 

$

382.0

 

Pipeline

 

 

498.3

 

 

 

492.4

 

All Other Property*

 

 

184.5

 

 

 

177.7

 

Total property, plant and equipment

 

$

1,136.6

 

 

$

1,052.1

 

Accumulated depreciation

 

 

(129.4

)

 

 

(96.8

)

Property, plant and equipment, net

 

$

1,007.2

 

 

$

955.3

 

* Primarily consisting of computer software and hardware

 

 

 

 

 

 

Accrued Capital Expenditures – Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid.

 

September 30

 

2025

 

 

2024

 

 

2023

 

Spire

 

$

82.5

 

 

$

116.5

 

 

$

104.3

 

Spire Missouri

 

 

61.8

 

 

 

67.4

 

 

 

56.5

 

Spire Alabama

 

 

9.5

 

 

 

14.1

 

 

 

4.6

 

 

ASSET RETIREMENT OBLIGATIONS – Spire, Spire Missouri and Spire Alabama record legal obligations associated with the retirement of long-lived assets in the period in which the obligations are incurred, if sufficient information exists to reasonably estimate the fair value of the obligations. Obligations are recorded as both a cost of the related long-lived asset and as a corresponding liability. Subsequently, the asset retirement costs are depreciated over the life of the asset and the asset retirement obligations are accreted to the expected settlement amounts. Spire, Spire Missouri and Spire Alabama record asset retirement obligations associated with certain safety requirements to purge and seal gas distribution mains upon retirement, the plugging and abandonment of storage wells and other storage facilities, specific service line obligations, and certain removal and disposal obligations related to components of Spire Missouri’s, Spire Alabama’s and Spire Gulf’s distribution systems and general plant. Asset retirement obligations recorded by Spire’s other subsidiaries are not material. As authorized by the MoPSC and the APSC, Spire Missouri, Spire Alabama and Spire Gulf accrue future asset removal costs associated with their property, plant and equipment even if a legal obligation does not exist. Such accruals are provided for through depreciation expense and are recorded with corresponding credits to regulatory liabilities or regulatory assets. When those utilities retire depreciable utility plant and equipment, they charge the associated original costs to accumulated depreciation and amortization, and any related removal costs incurred are charged to regulatory liabilities or regulatory assets. The difference between removal costs recognized in depreciation rates and the accretion expense and depreciation expense recognized for financial reporting purposes is a timing difference between recovery of these costs in rates and their recognition for financial reporting purposes. Accordingly, these differences are deferred as regulatory liabilities or regulatory assets. In the rate setting process, the regulatory liabilities or regulatory assets are excluded from the rate base upon which those utilities have the opportunity to earn their allowed rates of return.

The following table presents a reconciliation of the beginning and ending balances of asset retirement obligations at September 30, as reported in the balance sheets.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Asset retirement obligations, beginning of year

 

$

579.9

 

 

$

577.4

 

 

$

95.7

 

 

$

111.1

 

 

$

468.6

 

 

$

451.0

 

Liabilities incurred during the period

 

 

3.1

 

 

 

2.5

 

 

 

0.4

 

 

 

0.4

 

 

 

2.2

 

 

 

1.4

 

Liabilities settled during the period

 

 

(5.1

)

 

 

(6.5

)

 

 

(2.8

)

 

 

(2.9

)

 

 

(0.9

)

 

 

(1.3

)

Accretion

 

 

25.0

 

 

 

24.8

 

 

 

3.9

 

 

 

4.5

 

 

 

20.4

 

 

 

19.6

 

Revisions in estimated cash flows

 

 

(19.7

)

 

 

(18.3

)

 

 

(1.7

)

 

 

(17.4

)

 

 

(20.3

)

 

 

(2.1

)

Asset retirement obligations, end of year

 

$

583.2

 

 

$

579.9

 

 

$

95.5

 

 

$

95.7

 

 

$

470.0

 

 

$

468.6

 

 

NATURAL GAS AND PROPANE GAS – For Spire Missouri’s eastern region, inventory of natural gas in storage is priced on a last in, first out (LIFO) basis and inventory of propane gas in storage is priced on a first in, first out (FIFO) basis. For the rest of the Gas Utility segment, inventory of natural gas in storage is priced on the weighted average cost basis. The replacement cost of Spire Missouri’s natural gas for current use in eastern Missouri at September 30, 2025 and 2024 was less than the LIFO cost by $21.3 and $27.3, respectively. The carrying value of the Utilities’ inventory is never adjusted to a lower net realizable value or market value because, pursuant to PGA clauses or a GSA rider, actual gas costs are recovered in customer rates. Natural gas and propane gas storage inventory in Spire’s other segments is recorded at the lower of average cost or net realizable value.

GOODWILL – Spire’s acquisitions were accounted for using business combination accounting. Under this method, the purchase price paid by the acquirer is allocated to the assets acquired and liabilities assumed as of the acquisition date based on their fair value. Goodwill is measured as the excess of the acquisition-date fair value of the consideration transferred over the amount of acquisition-date identifiable assets acquired net of assumed liabilities. At September 30, 2025, goodwill included in Spire’s Gas Utility, Gas Marketing, and Midstream segments was $210.2, zero, and zero, respectively, with the remainder held at the corporate level. Goodwill amounts have not changed since fiscal 2017, and there are no accumulated impairment losses. Spire and Spire Missouri evaluate goodwill for impairment as of July 1 of each year, or more frequently if events and circumstances indicate that goodwill might be impaired. At each test date, the assessments concluded that goodwill was not impaired. The Company updated the assessments as of September 30, 2025, determining that it remained more likely than not that the fair value of each reporting unit exceeded its carrying value.

IMPAIRMENT OF LONG-LIVED ASSETS – Long-lived assets classified as held and used are evaluated for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Whether impairment has occurred is determined by comparing the estimated undiscounted cash flows attributable to the assets with the carrying value of the assets. If the carrying value exceeds the undiscounted cash flows, the Company recognizes an impairment charge equal to the amount of the carrying value that exceeds the estimated fair value of the assets. In the period in which the Company determines an asset meets held-for-sale criteria, an impairment charge is recorded to the extent the book value exceeds its fair value less cost to sell.

DERIVATIVES – In the course of their business, certain subsidiaries of Spire enter into commitments associated with the purchase or sale of natural gas. Certain of their derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of FASB ASC Topic 815, Derivatives and Hedging. Those contracts are accounted for as executory contracts and recorded on an accrual basis. Revenues and expenses from such contracts are recorded gross. Contracts not designated as normal purchases or normal sales are recorded as derivatives with changes in fair value recognized in earnings in the periods prior to physical delivery. Certain of Spire Marketing’s wholesale purchase and sale transactions are classified as trading activities for financial reporting purposes, with income and expenses presented on a net basis in natural gas expenses in the Consolidated Statements of Income. Spire also enters into cash flow hedges through execution of interest rate swap contracts to protect itself against adverse movements in interest rates. In the first quarter of fiscal 2024, considering changes in debt issuance strategy due to the interest rate environment, Spire management determined it was probable the anticipated issuance of certain debt, and therefore the hedged forecasted interest payments, would not occur. The related swap was settled, hedge accounting was discontinued, and amounts previously deferred in “Accumulated other comprehensive income” were reclassified to earnings, such that the entire realized gain of $8.2 was included in “Other income” for Spire Inc. in the quarter ended December 31, 2023. Refer to Note 10, Derivative Instruments and Hedging Activities, for more information about derivatives.

INCOME TAXES – Spire and its subsidiaries account for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amount of existing assets and liabilities and the respective tax basis and for tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be realized or settled. The effects on deferred tax assets and liabilities of a change in enacted tax rates is recognized in income or loss for non-regulated operations, and in a regulatory asset or regulatory liability for regulated operations. A valuation allowance is established when it is more likely than not that some portion or all of the deferred tax assets will not be realized.

The Company accounts for uncertain tax positions in accordance with authoritative guidance. The authoritative guidance addresses the determination of whether tax benefits claimed, or expected to be claimed, on a tax return should be recorded in the financial statements. Spire may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the position will be sustained upon examination by the taxing authority, based on the technical merits of the position. Tax-related interest and penalties, if any, are classified as a liability on the balance sheets. For additional information on the accounting for income taxes, refer to Note 12, Income Taxes.

CASH, CASH EQUIVALENTS, AND RESTRICTED CASH – All highly liquid debt instruments purchased with original maturities of three months or less are considered to be cash equivalents. Such instruments are carried at cost, which approximates market value. Outstanding checks on the Company’s and Utilities’ bank accounts in excess of funds on deposit create book overdrafts (which are funded at the time checks are presented for payment) and are classified as Other in the Current Liabilities section of the balance sheets. Changes in book overdrafts are reflected as Operating Activities in the statements of cash flows.

In Spire’s statements of cash flows, total Cash, Cash Equivalents, and Restricted Cash included $35.5 and $30.4 of restricted cash reported in “Other Investments” on the Company’s balance sheet as of September 30, 2025 and 2024, respectively (in addition to amounts shown as “Cash and cash equivalents”). This restricted cash has been segregated and invested in debt securities in trust accounts based on collateral requirements for reinsurance at Spire’s risk management company.

NATURAL GAS RECEIVABLE – Spire Marketing enters into natural gas transactions with natural gas pipeline and storage companies known as park and loan arrangements. Under the terms of the arrangements, Spire Marketing purchases natural gas from a third party and delivers that natural gas to the pipeline or storage company for the right to receive the same quantity of natural gas from that company at the same location in a future period. These arrangements are accounted for as non-monetary transactions under GAAP and are recorded at the carrying amount. As such, natural gas receivables are reflected in “Other” current assets on the Consolidated Balance Sheets at cost, which includes related fees associated with the transactions. In the period that the natural gas is returned to Spire Marketing, concurrent with the sale of the natural gas to a third party, the related natural gas receivable is expensed in the Consolidated Statements of Income. In conjunction with these transactions, Spire Marketing usually enters into New York Mercantile Exchange (NYMEX) and Intercontinental Exchange (ICE) natural gas futures, options, and swap contracts or fixed price sales agreements to protect against market changes in future sales prices.

EARNINGS PER COMMON SHARE – GAAP requires dual presentation of basic and diluted earnings per share (EPS). EPS is computed using the two-class method, which is an earnings allocation method for computing EPS that treats a participating security as having rights to earnings that would otherwise have been available to common shareholders. Certain of the Company’s stock-based compensation awards pay non-forfeitable dividends to the participants during the vesting period and, as such, are deemed participating securities. Basic EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding that are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common shares, pursuant to the treasury stock method. Shares attributable to equity units, common stock forward purchase contracts, non-participating performance-contingent restricted stock awards, and time-vested restricted stock/units are excluded from the calculation of diluted earnings per share if the effect would be antidilutive. Shares attributable to non-participating performance-contingent restricted stock awards are only included in the calculation of diluted earnings per share to the extent the underlying performance and/or market conditions are satisfied (a) prior to the end of the reporting period or (b) would be satisfied if the end of the reporting period were the end of the related contingency period and the result would be dilutive. The Company’s EPS computations are presented in Note 4, Earnings Per Common Share.

TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated financial statements of Spire. Spire Missouri and Spire Alabama borrowed funds from the Company and incurred related interest, as reflected in their separate financial statements, and they participated in normal intercompany shared services transactions. In addition, Spire Missouri’s and Spire Alabama’s other transactions with affiliates included:

 

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Natural gas purchases from Spire Marketing

 

$

23.8

 

 

$

13.9

 

 

$

57.4

 

 

$

13.9

 

 

$

6.7

 

 

$

4.7

 

Natural gas sales to Spire Marketing

 

 

0.1

 

 

 

1.7

 

 

 

0.4

 

 

 

—

 

 

 

—

 

 

 

—

 

Transportation services from Spire STL Pipeline LLC

 

 

32.0

 

 

 

32.5

 

 

 

32.0

 

 

 

—

 

 

 

—

 

 

 

—

 

Natural gas storage services from Spire Storage Salt Plains
   LLC

 

 

—

 

 

 

0.7

 

 

 

0.7

 

 

 

—

 

 

 

—

 

 

 

—

 

Transportation services from Spire MoGas Pipeline LLC

 

 

7.0

 

 

 

4.8

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES – Trade accounts receivable are recorded at the amounts due from customers, including unbilled amounts. Accounts receivable are written off when they are deemed to be uncollectible. An allowance for expected credit losses is estimated and updated based on relevant data and trends such as accounts receivable aging, historical write-off experience, current write-off trends, economic conditions, and the impact of weather and availability of customer payment assistance on collection trends. For the Utilities, net write-offs as a percentage of revenue has historically been the best predictor of base net write-off experience over time. Management judgment is applied in the development of the allowance due to the complexity of variables and subjective nature of certain relevant factors. The accounts receivable of Spire’s non-utility businesses are evaluated separately from those of the Utilities. The allowance for credit losses for those other businesses is based on a continuous evaluation of the individual counterparty risk and is not significant for the periods presented. Activity in the allowance for credit losses is shown in the following table.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Allowance at beginning of year

 

$

31.4

 

 

$

32.5

 

 

$

31.9

 

 

$

24.9

 

 

$

26.2

 

 

$

24.9

 

 

$

5.7

 

 

$

5.7

 

 

$

6.3

 

Provision for expected credit losses

 

 

19.6

 

 

 

23.0

 

 

 

16.6

 

 

 

14.8

 

 

 

19.0

 

 

 

13.3

 

 

 

4.0

 

 

 

3.2

 

 

 

2.6

 

Write-offs, net of recoveries

 

 

(22.2

)

 

 

(24.1

)

 

 

(16.0

)

 

 

(16.7

)

 

 

(20.3

)

 

 

(12.0

)

 

 

(4.8

)

 

 

(3.2

)

 

 

(3.2

)

Allowance at end of year

 

$

28.8

 

 

$

31.4

 

 

$

32.5

 

 

$

23.0

 

 

$

24.9

 

 

$

26.2

 

 

$

4.9

 

 

$

5.7

 

 

$

5.7

 

 

FINANCE RECEIVABLES – Spire Alabama finances third party contractor sales of merchandise including gas furnaces and appliances. At September 30, 2025 and 2024, Spire Alabama’s finance receivable totaled approximately $5.4 and $5.9, respectively. Financing is available only to qualified customers who meet creditworthiness thresholds for customer payment history and external agency credit reports. Spire Alabama relies upon ongoing payments as the primary indicator of credit quality during the term of each contract. The allowance for credit losses is recognized using an estimate of write-off percentages based on historical experience. Delinquent accounts are evaluated on a case-by-case basis and, absent evidence of debt repayment, after 90 days are due in full and assigned to a third-party collection agency. The remaining finance receivable is written off approximately 12 months after being assigned to the third-party collection agency. Spire Alabama had finance receivables past due 90 days or more of $0.4 and $0.4 at September 30, 2025 and 2024, respectively.

GROUP MEDICAL AND WORKERS’ COMPENSATION RESERVES – The Company self-insures its group medical and workers’ compensation costs and carries stop-loss coverage in relation to medical claims and workers’ compensation claims. Reserves for amounts incurred but not reported are established based on historical cost levels and lags between occurrences and reporting.

FAIR VALUE MEASUREMENTS – Certain assets and liabilities are recognized or disclosed at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value.

The levels of the hierarchy are described below:

•
Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities.
•
Level 2 – Pricing inputs other than quoted prices included within Level 1, which are either directly or indirectly observable for the asset or liability as of the reporting date. These inputs are derived principally from, or corroborated by, observable market data.
•
Level 3 – Pricing that is based upon inputs that are generally unobservable that are based on the best information available and reflect management’s assumptions about how market participants would price the asset or liability.

Assessment of the significance of a particular input to the fair value measurements may require judgment and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. Additional information about fair value measurements is provided in Note 8, Fair Value of Financial Instruments, Note 9, Fair Value Measurements, and Note 13, Pension Plans and Other Postretirement Benefits.

STOCK-BASED COMPENSATION – The Company accounts for share-based compensation arrangements in accordance with ASC Topic 718, Compensation – Stock Compensation. The Company measures stock-based compensation awards at fair value at the date of grant and recognizes the compensation cost of the awards over the requisite service period. Forfeitures are recognized in the period they occur. Refer to Note 3, Stock-Based Compensation, for further discussion of the accounting for the Company’s stock-based compensation plans.

NEW ACCOUNTING PRONOUNCEMENTS - On September 30, 2025, the Companies adopted ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which updates segment disclosure requirements through enhanced disclosures around significant segment expenses. The Companies applied the provision retrospectively to all periods presented for each reportable segment as further described. Refer to Note 14, for further discussion of segment reporting.

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income (Topic 220): Expense Disaggregation Disclosures (“ASU 2024-03”). This ASU improves disclosure of a public business entity’s expense by requiring disaggregated disclosure of expenses in commonly presented expense captions. ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and for interim periods beginning after December 15, 2027. Early adoption is permitted. The Companies are currently evaluating the impact of this ASU on their respective consolidated financial statements.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”). This ASU enhances the transparency of income tax disclosures related to rate reconciliation and income taxes. ASU 2023-09 is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. The Companies are currently evaluating the impact of this ASU on their respective consolidated financial statements.

Management believes that all other recently adopted and recently issued accounting standards that are not yet effective will not have a material impact on the Companies financial position, results of operations or cash flows upon adoption.
v3.25.3
Revenue
 12 Months Ended
Sep. 30, 2025
Revenue from Contract with Customer [Abstract]  
Revenue

2. REVENUE

The following tables show revenue disaggregated by source and customer type.

 

 

 

2025

 

 

2024

 

 

2023

 

Spire

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

Residential

 

$

1,462.6

 

 

$

1,617.4

 

 

$

1,648.5

 

Commercial & industrial

 

 

501.3

 

 

 

581.0

 

 

 

606.0

 

Transportation

 

 

133.6

 

 

 

130.0

 

 

 

121.6

 

Off-system & other incentive

 

 

65.3

 

 

 

37.0

 

 

 

30.0

 

Other customer revenue

 

 

24.4

 

 

 

21.2

 

 

 

16.1

 

Total revenue from contracts with customers

 

 

2,187.2

 

 

 

2,386.6

 

 

 

2,422.2

 

Changes in accrued revenue under alternative revenue programs

 

 

20.3

 

 

 

51.3

 

 

 

34.7

 

Total Gas Utility operating revenues

 

 

2,207.5

 

 

 

2,437.9

 

 

 

2,456.9

 

Gas Marketing

 

 

157.2

 

 

 

99.2

 

 

 

179.1

 

Midstream

 

 

155.5

 

 

 

100.7

 

 

 

66.1

 

Other

 

 

20.6

 

 

 

17.6

 

 

 

16.7

 

Total before eliminations

 

 

2,540.8

 

 

 

2,655.4

 

 

 

2,718.8

 

Intercompany eliminations

 

 

(64.4

)

 

 

(62.4

)

 

 

(52.5

)

Total Operating Revenues

 

$

2,476.4

 

 

$

2,593.0

 

 

$

2,666.3

 

Spire Missouri

 

 

 

 

 

 

 

 

 

Residential

 

$

1,092.1

 

 

$

1,217.7

 

 

$

1,261.3

 

Commercial & industrial

 

 

326.0

 

 

 

390.9

 

 

 

411.9

 

Transportation

 

 

35.9

 

 

 

34.1

 

 

 

33.2

 

Off-system & other incentive

 

 

51.9

 

 

 

28.8

 

 

 

20.1

 

Other customer revenue

 

 

14.0

 

 

 

14.9

 

 

 

12.5

 

Total revenue from contracts with customers

 

 

1,519.9

 

 

 

1,686.4

 

 

 

1,739.0

 

Changes in accrued revenue under alternative revenue programs

 

 

24.2

 

 

 

51.0

 

 

 

23.9

 

Total Operating Revenues

 

$

1,544.1

 

 

$

1,737.4

 

 

$

1,762.9

 

Spire Alabama

 

 

 

 

 

 

 

 

 

Residential

 

$

307.5

 

 

$

336.4

 

 

$

322.9

 

Commercial & industrial

 

 

134.5

 

 

 

149.5

 

 

 

150.4

 

Transportation

 

 

87.3

 

 

 

85.1

 

 

 

77.6

 

Off-system & other incentive

 

 

13.4

 

 

 

8.1

 

 

 

9.9

 

Other customer revenue

 

 

6.3

 

 

 

(0.4

)

 

 

3.6

 

Total revenue from contracts with customers

 

 

549.0

 

 

 

578.7

 

 

 

564.4

 

Changes in accrued revenue under alternative revenue programs

 

 

(3.8

)

 

 

0.2

 

 

 

6.7

 

Total Operating Revenues

 

$

545.2

 

 

$

578.9

 

 

$

571.1

 

 

The Utilities sell natural gas to residential and other customers. The sale of natural gas is governed by the various state utility commissions, which set rates, charges, and terms and conditions of service, collectively included in a “tariff.” The performance obligation, which relates to the promise to provide natural gas, is satisfied over time as the customer simultaneously receives and consumes the natural gas, and revenue is recognized accordingly.

 

From time to time, the Utilities will sell natural gas to other customers outside its normal customer base or designated service territory. Off-system sales agreements with customers are entered into on an ad-hoc basis for the sale of a specific volume of gas at a specific delivery point at an agreed upon rate. Performance obligations associated with off-system sales are satisfied, and revenue is recognized, at the point in time when the agreed upon volume of natural gas is delivered, and title is transferred, in accordance with the contract terms.

The Utilities’ transportation revenue relates to the promise to transport the specified quantities of natural gas at tariff rates. This performance obligation is satisfied over time as the gas is transported, and revenue is recognized as invoiced monthly.

The Utilities have alternative revenue programs (ARPs), which represent an agreement between the utility and its regulator, currently consisting of decoupling mechanisms (also known as weather normalization adjustments) and incentive programs (primarily Alabama’s Cost Control Measure). When the criteria to recognize additional (or reduced) revenue from ARPs have been met, the Utilities establish a regulatory asset (or liability). When amounts previously recognized for ARPs are billed, the Utilities reduce the regulatory asset (or liability) and increase (or decrease) accounts receivable. Billed amounts, which are part of the overall tariff paid by customers, are included in revenue from contracts with customers, while the change in the related regulatory asset or liability is presented as revenue from ARPs. Depending on whether the beginning accrued ARP balance was a regulatory asset or liability and depending on the size and direction of the current period accrual, the amount presented as revenue from ARPs could be negative.

The Utilities read meters and bill customers on monthly cycles. Spire Missouri, Spire Gulf and Spire Mississippi record their gas utility revenues from gas sales and transportation services on an accrual basis that includes estimated amounts for gas delivered but not yet billed. The accruals for unbilled revenues are reversed in the subsequent accounting period when meters are actually read and customers are billed. Spire Alabama records natural gas distribution revenues in accordance with the tariff established by the APSC. Unbilled revenue is accrued in an amount equal to the related gas cost, as profit margin is not considered earned until billed. The Utilities, including Spire Missouri and Spire Alabama, have elected to apply the “right to invoice” practical expedient, recognizing revenue for volumes delivered for which they have a right to invoice as that amount corresponds with the value to the customer.

Gas Marketing’s contracts are derivatives. Wholesale contracts (with producers, municipalities, and utility companies) are subject to derivative accounting. Retail contracts (with large commercial and industrial customers) are designated as “normal purchase, normal sale” arrangements and are therefore accounted for as revenue from contracts with customers. The performance obligation is satisfied upon the transfer of control of natural gas to the customer, and revenue is recognized as invoiced monthly. Revenue is recognized monthly based on amounts invoiced using the “right to invoice” practical expedient.

Midstream revenues are primarily derived from firm transportation or storage service agreements, which provide customers with guaranteed access to natural gas transportation capacity to transport gas between receipt and delivery points or storage capacity and related injection and withdrawal rights. These agreements include a single performance obligation—the stand-ready service to provide firm transportation or storage capacity throughout the contract term, which is satisfied over time. The transaction price consists of fixed fees, which represents the customer’s access to transportation or storage capacity, and variable charges, which are based on volumes that are shipped, injected or withdrawn. Revenue is recognized using the right to invoice practical expedient based on amounts invoiced to the customer each month.

Payments are generally required within 30 days of billing, and contracts generally do not have a significant financing component. Spire’s revenues are not subject to significant returns, refunds, or warranty obligations.

Disclosures about remaining performance obligations are not required because either contracts have an original expected duration of one year or less, or revenue is recognized under the right to invoice practical expedient, or both.

Sales taxes imposed on applicable Spire Alabama and Spire Missouri sales are billed to customers. These amounts are not recorded in the statements of income but are recorded as tax collections payable and included in the “Other” line of the Current Liabilities section of the balance sheets.

Gross receipts taxes associated with the Company’s natural gas utility services are imposed on the Company, Spire Missouri, and Spire Alabama and billed to its customers. The expense amounts (shown in the table below) are reported gross in the “Taxes, other than income taxes” line in the statements of income, and corresponding revenues are reported in “Operating Revenues.”

 

 

 

2025

 

 

2024

 

 

2023

 

Spire

 

$

115.7

 

 

$

128.2

 

 

$

131.8

 

Spire Missouri

 

 

82.9

 

 

 

93.1

 

 

 

96.7

 

Spire Alabama

 

 

27.9

 

 

 

30.1

 

 

 

29.9

 
v3.25.3
Stock-based Compensation
 12 Months Ended
Sep. 30, 2025
Share-Based Payment Arrangement [Abstract]  
Stock-based Compensation

3. STOCK-BASED COMPENSATION

The Spire 2015 Equity Incentive Plan (EIP) was approved by shareholders of Spire on January 29, 2015 and amended on November 9, 2018. The 2015 EIP was replaced by the 2025 Equity Incentive Plan (EIP), which was approved by shareholders on January 30, 2025. The purpose of the EIP is to encourage directors, officers, and key employees of the Company and its subsidiaries to contribute to the Company’s success and align their interests with that of shareholders. To accomplish this purpose, the Compensation and Human Resources Committee (“Committee”) of Spire’s Board of Directors (the “Board”) may grant awards under the EIP that may be earned by achieving performance objectives and/or other criteria as determined by the Committee. Under the terms of the EIP, officers and employees of the Company and its subsidiaries, as determined by the Committee, are eligible to be selected for awards. The EIP provides for restricted stock, restricted stock units, qualified and non-qualified stock options, stock appreciation rights, and performance shares payable in stock, cash, or a combination of both. The EIP generally provides a minimum vesting period of at least three years for each type of award, with pro rata vesting permitted during the minimum three-year vesting period. The maximum number of shares reserved for issuance under the EIP is 1,500,000.

The Company allows participants in the EIP the ability to defer a portion or all of their award. As of September 30, 2025, a total of 79,815 share equivalents (at target payout) have been deferred by participants. Such units are included in the data presented below. After the required holding period, deferred awards are ultimately paid in cash rather than in shares of

stock. Upon vesting, the Company issues new shares to satisfy awards that are not deferred. Effective with the fiscal 2026 grants, deferral of awards will no longer be an option available to grantees.

Restricted Stock Awards

During fiscal 2025, the Company granted 103,780 performance-contingent restricted share units to executive officers and key employees at a weighted average grant date fair value of $76.52 per share. This number represents the target shares that can be earned pursuant to the terms of the awards. The share units have a performance period ending September 30, 2027. While the participants have no interim voting rights on these share units, dividends accrue during the performance period and are paid to the participants upon vesting but are subject to forfeiture if the underlying share units do not vest.

The number of share units that will ultimately vest is dependent upon the attainment of certain levels of earnings, as well as the Company’s level of total shareholder return (TSR) during the performance period relative to a comparator group of peer companies. This TSR provision is considered a market condition under GAAP and is discussed further below. The maximum amount of shares or share equivalents that can be earned pursuant to the terms of the awards is 200% of the target units granted.

The weighted average grant date fair value of performance-contingent restricted share units granted during fiscal years 2024 and 2023 was $74.23 and $79.88 per share, respectively.

Fiscal 2025 activity of restricted stock units subject to performance and/or market conditions is presented below:

 

 

 

Units

 

 

Weighted
Average
Grant Date
Fair Value
Per Unit

 

Non-vested at September 30, 2024

 

 

289,205

 

 

$

73.36

 

Granted

 

 

103,780

 

 

$

76.52

 

Adjusted for performance

 

 

21,469

 

 

$

65.02

 

Vested

 

 

(100,784

)

 

$

65.02

 

Forfeited

 

 

(69,166

)

 

$

74.67

 

Non-vested at September 30, 2025

 

 

244,504

 

 

$

75.62

 

 

For the year ended September 30, 2025, the total number of shares or share equivalents that could be issued if all outstanding award grants attain maximum performance payout is 564,862.

During fiscal 2025, the Company granted 57,030 shares of time-vested restricted stock to executive officers and key employees at a weighted average grant date fair value of $72.00 per share. Unless forfeited based on terms of the agreements, these shares will vest in fiscal 2028. In the interim, participants receive full voting rights and dividends, which are not subject to forfeiture. The weighted average grant date fair value of time-vested restricted stock and restricted stock units awarded to employees during fiscal years 2024 and 2023 was $60.68 and $71.91 per share, respectively.

During fiscal 2025, the Company granted 15,750 shares of time-vested restricted stock to non-employee directors at a weighted average grant date fair value of $71.38 per share. These shares vested in fiscal 2025, six months after the grant date. The weighted average grant date fair value of restricted stock awarded to non-employee directors during fiscal years 2024 and 2023 was $58.03 and $75.59 per share, respectively.

Time-vested restricted stock and stock unit activity for fiscal 2025 is presented below:

 

 

 

Shares/
Units

 

 

Weighted
Average
Grant Date
Fair Value
Per Share

 

Non-vested at September 30, 2024

 

 

85,559

 

 

$

64.13

 

Granted

 

 

57,030

 

 

$

72.00

 

Vested

 

 

(42,677

)

 

$

66.36

 

Forfeited

 

 

(23,348

)

 

$

67.61

 

Non-vested at September 30, 2025

 

 

76,564

 

 

$

67.20

 

 

For restricted stock and stock units (performance-contingent and time-vested) that vested during fiscal years 2025, 2024, and 2023, the Company withheld 26,892 shares, 24,724 shares, and 18,428 shares, respectively, at weighted average prices of $73.45, $60.73 and $72.03 per share, respectively, pursuant to elections by employees to satisfy tax withholding obligations. The total fair value of restricted stock (performance-contingent and time-vested) that vested during fiscal years 2025, 2024, and 2023 was $8.0, $11.9, and $8.6, respectively, and the related tax benefit was $4.0, $3.7, and $3.2, respectively. None of the tax benefits have been realized.

Equity Compensation Costs

Compensation cost for performance-contingent restricted stock and stock unit awards is based upon the probable outcome of the performance conditions. For shares or units that do not vest or that are not expected to vest due to the outcome of the performance conditions (excluding market conditions), no compensation cost is recognized and any previously recognized compensation cost is reversed.

The fair value of awards of performance-contingent and time-vested restricted stock and restricted stock units, not subject to the TSR provision, are estimated using the closing price of the Company’s stock on the grant date. For those awards that do not pay dividends during the vesting period, the estimate of fair value is reduced by the present value of the dividends expected to be paid on the Company’s common stock during the performance period, discounted using an appropriate U.S. Treasury yield. For shares subject to the TSR provision, the estimated impact of this market condition is reflected in the grant date fair value per share of the awards. Accordingly, compensation cost is not reversed to reflect any actual reductions in the awards that may result from the TSR provision. The grant date fair value of the awards subject to the TSR provision awarded during fiscal years 2024, 2023 and 2022 was valued by a Monte Carlo simulation model that assessed the probabilities of various TSR outcomes. The significant assumptions used in the Monte Carlo simulations are as follows:

 

 

 

2025

 

2024

 

2023

Risk-free interest rate

 

4.33%

 

4.66%

 

4.26%

Expected dividend yield of stock

 

—

 

—

 

—

Expected volatility of stock

 

22.2%

 

23.3%

 

33.8%

Performance period (in years)

 

3.0

 

3.0

 

3.0

 

The risk-free interest rate was based on the yield on U.S. Treasury securities matching the vesting period. A zero-percent dividend yield was used, which is mathematically equivalent to the assumption that dividends are reinvested as they are paid. The expected volatility is based on the historical volatility of the Company’s stock. Volatility assumptions were also made for each of the companies included in the comparator group. The vesting period is equal to the performance period set forth in the terms of the award.

The amounts of compensation cost recognized for share-based compensation arrangements are presented below:

 

 

 

2025

 

 

2024

 

 

2023

 

Total compensation cost

 

$

7.8

 

 

$

6.6

 

 

$

11.2

 

Compensation cost capitalized

 

 

(1.1

)

 

 

(0.8

)

 

 

(1.4

)

Compensation cost recognized in net income

 

 

6.7

 

 

 

5.8

 

 

 

9.8

 

Income tax benefit recognized in net income

 

 

(1.5

)

 

 

(1.3

)

 

 

(2.2

)

Compensation cost recognized in net income, net of income tax

 

$

5.2

 

 

$

4.5

 

 

$

7.6

 

 

As of September 30, 2025, there was $8.7 of total unrecognized compensation cost related to non-vested share-based compensation arrangements, which is expected to be recognized over a weighted average period of 1.8 years.
v3.25.3
Earnings Per Common Share
 12 Months Ended
Sep. 30, 2025
Earnings Per Share [Abstract]  
Earnings Per Common Share

4. EARNINGS PER COMMON SHARE

 

 

 

2025

 

 

2024

 

 

2023

 

Basic Earnings Per Common Share:

 

 

 

 

 

 

 

 

 

Net Income

 

$

271.7

 

 

$

250.9

 

 

$

217.5

 

Less: Provision for preferred dividends

 

 

14.8

 

 

 

14.8

 

 

 

14.8

 

Income allocated to participating securities

 

 

0.3

 

 

 

0.3

 

 

 

0.3

 

Net Income Available to Common Shareholders

 

$

256.6

 

 

$

235.8

 

 

$

202.4

 

Weighted Average Common Shares Outstanding (in millions)

 

 

58.5

 

 

 

56.1

 

 

 

52.5

 

Basic Earnings Per Share of Common Stock

 

$

4.39

 

 

$

4.20

 

 

$

3.86

 

Diluted Earnings per Common Share:

 

 

 

 

 

 

 

 

 

Net Income

 

$

271.7

 

 

$

250.9

 

 

$

217.5

 

Less: Provision for preferred dividends

 

 

14.8

 

 

 

14.8

 

 

 

14.8

 

Income allocated to participating securities

 

 

0.3

 

 

 

0.3

 

 

 

0.3

 

Net Income Available to Common Shareholders

 

$

256.6

 

 

$

235.8

 

 

$

202.4

 

Weighted Average Common Shares Outstanding (in millions)

 

 

58.5

 

 

 

56.1

 

 

 

52.5

 

Dilutive Effect of Restricted Stock and Restricted Stock Units
   (in millions)*

 

 

0.2

 

 

 

0.2

 

 

 

0.1

 

Weighted Average Diluted Common Shares (in millions)

 

 

58.7

 

 

 

56.3

 

 

 

52.6

 

Diluted Earnings Per Share of Common Stock

 

$

4.37

 

 

$

4.19

 

 

$

3.85

 

 

 

 

 

 

 

 

 

 

 

* Calculation excludes certain outstanding common shares (shown in
   millions by period at the right) attributable to common stock forward
   contracts, stock units subject to performance or market conditions, and
   restricted stock, which could have a dilutive effect in the future

 

 

0.2

 

 

 

0.1

 

 

 

1.9

 
v3.25.3
Shareholders' Equity
 12 Months Ended
Sep. 30, 2025
Stockholders' Equity Note [Abstract]  
Shareholders' Equity

5. SHAREHOLDERS’ EQUITY

Spire

Preferred Stock

At September 30, 2025 and 2024, Spire had authorized 5,000,000 shares of preferred stock.

On May 21, 2019, Spire completed the public offering of 10,000,000 depositary shares (the “Depositary Shares”), each representing a 1/1,000th interest in a share of the Company’s 5.90% Series A Cumulative Redeemable Perpetual Preferred Stock, par value $25.00 per share, with a liquidation preference of $25,000 per share (the “Preferred Stock”). The transaction resulted in the issuance of 10,000 shares of preferred stock for $242.0 of net proceeds.

Dividends on the Preferred Stock, when declared by the Board, are payable on the liquidation preference amount, on a cumulative basis, quarterly in arrears on the 15th day of February, May, August and November of each year. Dividends are payable out of amounts legally available for the payment of dividends at an annual rate equal to 5.90% of the liquidation preference per share of Preferred Stock (equivalent to $25.00 per Depositary Share). Under the terms of the Preferred Stock, the Company’s ability to declare or pay dividends on, or purchase or redeem, shares of its common stock or any class or series of capital stock of the Company that rank junior to the Preferred Stock are subject to certain restrictions in the event that the Company does not declare and pay the full cumulative dividends on the Preferred Stock through the most recently completed quarterly dividend period.

Spire may, at its option, redeem the Preferred Stock in whole or in part, from time to time, at a redemption price in cash equal to $25,000 per share, plus all accumulated and unpaid dividends (whether declared or not) up to the redemption date.

Shareholders of the Preferred Stock generally have no voting rights with respect to matters that generally require the approval of voting stockholders. The limited voting rights of holders of the Preferred Stock include the right to vote on certain matters that may affect the preference or special rights of the Preferred Stock. In addition, if and whenever dividends on any shares of Preferred Stock have not been declared and paid for at least six dividend periods, whether or not consecutive, the number of directors then constituting the Board shall automatically be increased by two (to be elected by the holders of the Preferred Stock) until all accumulated and unpaid dividends on the Preferred Stock have been paid in full.

Equity Units

In February 2021, Spire issued 3.5 million equity units, initially in the form of Corporate Units (as defined in the Underwriting Agreement, dated February 9, 2021, filed as Exhibit 1.1 to the Company’s Current Report on Form 8-K filed on February 16, 2021). Each Corporate Unit was comprised of (i) a purchase contract obligating the holder to purchase from the Company for a price in cash of fifty dollars, on the purchase contract settlement date (March 1, 2024, subject to earlier termination or settlement), a certain number of shares of the Company’s common stock and (ii) a 1/20th, or 5%, undivided beneficial ownership interest in one thousand dollars principal amount of the Company’s 2021 Series A 0.75% Remarketable Senior Notes due 2026. Each Corporate Unit purchase contract obligated holders to purchase a variable number of shares of common stock of the Company based on the applicable market value, subject to anti-dilution adjustments. As of March 1, 2024, the applicable market value was calculated to be $58.6809 per share, and after adjustment the holders were obligated to purchase 0.7845 shares of common stock. The Corporate Unit holders purchased an aggregate of 2,745,733 shares of common stock (net of fractional shares) for $175.0, settled on March 5, 2024.

ATM Program

Under Spire’s “at-the-market” (ATM) equity distribution agreement and as authorized by its board of directors, the Company may offer and sell, from time to time, shares of its common stock (including shares of common stock that may be sold pursuant to forward sale agreements entered into in connection with the ATM equity distribution agreement). Settled sales under this ATM program are included in “Common stock issued” in the Consolidated Statements of Shareholders’ Equity. Specifically in the first quarter of fiscal 2024, on December 11, 2023, 1,744,549 shares were settled, generating $112.2 of net proceeds. On January 25, 2024, Spire’s board approved a new authorization for the sale of additional shares with an aggregate offering price of up to $200.0 through January 2027.

In the second and third quarters of fiscal 2024, Spire executed forward sale agreements for a total of 542,515 shares of its common stock, which were settled in December 2024, generating $32.4 of net proceeds. In the fourth quarter of fiscal 2024, Spire executed forward sale agreements for 663,619 shares of its common stock, which were settled in March 2025, generating proceeds of $42.4. As of September 30, 2025, there were no outstanding forward sales agreements.

As of September 30, 2025, under the ATM program, Spire may sell additional shares with an aggregate offering price of up to $123.6. The Company suspended activity under the ATM program beginning August 7, 2025, and such suspension will remain in effect until two business days after the Company files its Annual Report on Form 10-K for the fiscal year ended September 30, 2025.

Other Equity Information

Spire has a shelf registration statement on Form S-3 on file with the SEC for the issuance and sale of up to 250,000 shares of common stock under its Dividend Reinvestment and Direct Stock Purchase Plan. There were 196,135 and 218,141 shares at September 30, 2025 and 2024, respectively, remaining available for issuance under this Form S-3. Spire also has a universal shelf registration statement on Form S-3 on file with the SEC for the issuance of various equity and debt securities, which expires on May 6, 2028.

Spire Missouri

Substantially all of Spire Missouri’s plant is subject to the liens of its first mortgage bonds. The mortgage contains several restrictions on Spire Missouri’s ability to pay cash dividends on its common stock or to make loans to its parent company. These mortgage restrictions are applicable regardless of whether the stock is publicly held or held solely by Spire Missouri’s parent company. Under the most restrictive of these provisions, no cash dividend may be declared or paid if, after the dividend, the aggregate net amount spent for all dividends after September 30, 1953 would exceed a maximum amount determined by a formula set out in the mortgage. Under that formula, the maximum amount is the sum of $8.0 plus earnings applicable to common stock (adjusted for stock repurchases and issuances) for the period from September 30, 1953 to the last day of the quarter before the declaration or payment date for the dividends. As of September 30, 2025 and 2024, the amount under the mortgage’s formula that was available to pay dividends was $1,999.4 and $1,797.0, respectively, so all of Spire Missouri’s retained earnings were free from such restrictions.

Spire Missouri has a universal shelf registration statement on Form S-3 on file with the SEC for the issuance of various equity and debt securities, which expires on May 6, 2028. Effective October 27, 2024, Spire Missouri was authorized by the MoPSC to issue conventional term loans, first mortgage bonds, unsecured debt, preferred stock and common stock in an aggregate amount not to exceed $850.0 any time from that date through December 31, 2027. Under this authorization, through October 23, 2025, Spire Missouri has issued $74.4 of common stock and $350 of first mortgage bonds. Approximately $426.0 remains available for issuance under this authorization.

 

As of September 30, 2025 and 2024, Spire Missouri had authorized 1,480,000 shares of preferred stock, but none had been issued.

Spire Alabama

As of September 30, 2025 and 2024, Spire Alabama had authorized 120,000 shares of preferred stock, but none had been issued.

Accumulated Other Comprehensive Income

The components of accumulated other comprehensive income ("AOCI"), net of income taxes, recognized in the balance sheets at September 30 were as follows:

 

 

 

Net

 

 

Defined Benefit

 

 

Net Unrealized

 

 

 

 

 

 

Unrealized

 

 

Pension and

 

 

Gain (Loss) on

 

 

 

 

 

 

Gain (Loss)

 

 

Other

 

 

Available-for-

 

 

 

 

 

 

on Cash Flow

 

 

Postretirement

 

 

Sale Debt

 

 

 

 

 

 

Hedges

 

 

Benefit Plans

 

 

Securities

 

 

Total

 

Spire

 

 

 

 

 

 

 

 

 

 

 

 

Balance at September 30, 2023

 

$

50.5

 

 

$

(2.5

)

 

$

(0.4

)

 

$

47.6

 

Other comprehensive (loss) income

 

 

(36.3

)

 

 

0.5

 

 

 

0.3

 

 

 

(35.5

)

Balance at September 30, 2024

 

 

14.2

 

 

 

(2.0

)

 

 

(0.1

)

 

 

12.1

 

Other comprehensive income

 

 

5.9

 

 

 

1.3

 

 

 

0.1

 

 

 

7.3

 

Balance at September 30, 2025

 

$

20.1

 

 

$

(0.7

)

 

$

—

 

 

$

19.4

 

 

 

 

 

 

 

 

 

 

 

 

 

Spire Missouri

 

 

 

 

 

 

 

 

 

 

 

 

Balance at September 30, 2023

 

$

—

 

 

$

(2.5

)

 

$

—

 

 

$

(2.5

)

Other comprehensive income

 

 

—

 

 

 

0.5

 

 

 

—

 

 

 

0.5

 

Balance at September 30, 2024

 

 

—

 

 

 

(2.0

)

 

 

—

 

 

 

(2.0

)

Other comprehensive income

 

 

—

 

 

 

1.3

 

 

 

—

 

 

 

1.3

 

Balance at September 30, 2025

 

$

—

 

 

$

(0.7

)

 

$

—

 

 

$

(0.7

)

 

Income tax expense (benefit) recorded for items of other comprehensive income (loss) reported in the statements of comprehensive income is calculated by applying statutory federal, state, and local income tax rates applicable to ordinary income. The tax rates applied to individual items of other comprehensive income (loss) are similar within each reporting period. For the periods presented, Spire Alabama had no AOCI balances.
v3.25.3
Long-term Debt
 12 Months Ended
Sep. 30, 2025
Debt Disclosure [Abstract]  
Long-term Debt

6. LONG-TERM DEBT

The composition of long-term debt as of September 30 is shown in the following tables.

 

 

 

2025

 

 

2024

 

Spire

 

 

 

 

 

 

5.30% Senior Notes, due March 1, 2026

 

$

350.0

 

 

$

350.0

 

3.13% Senior Notes, due September 1, 2026

 

 

130.0

 

 

 

130.0

 

3.93% Senior Notes, due March 15, 2027

 

 

100.0

 

 

 

100.0

 

5.80% Senior Notes, due March 15, 2033

 

 

150.0

 

 

 

150.0

 

4.70% Senior Notes, due August 15, 2044

 

 

250.0

 

 

 

250.0

 

Total principal of Spire Missouri long-term debt (see below)

 

 

1,968.0

 

 

 

1,818.0

 

Total principal of Spire Alabama long-term debt (see below)

 

 

715.0

 

 

 

750.0

 

Other subsidiaries' long-term debt:

 

 

 

 

 

 

5.00% First Mortgage Bonds, due September 30, 2031

 

 

42.0

 

 

 

42.0

 

2.95% Notes, with annual principal payments through December 2034

 

 

104.1

 

 

 

111.1

 

5.61% First Mortgage Bonds, due October 15, 2037

 

 

30.0

 

 

 

30.0

 

3.52% First Mortgage Bonds, due September 30, 2049

 

 

40.0

 

 

 

40.0

 

Total principal of long-term debt

 

 

3,879.1

 

 

 

3,771.1

 

Less: Unamortized discounts and debt issuance costs

 

 

(22.2

)

 

 

(24.7

)

Less: Current portion

 

 

(487.5

)

 

 

(42.0

)

Long-term debt, excluding current portion

 

$

3,369.4

 

 

$

3,704.4

 

Spire Missouri

 

 

 

 

 

 

First Mortgage Bonds:

 

 

 

 

 

 

3.40% Series, due March 15, 2028

 

$

45.0

 

 

$

45.0

 

7.00% Series, due June 1, 2029

 

 

19.3

 

 

 

19.3

 

2.84% Series, due November 15, 2029

 

 

275.0

 

 

 

275.0

 

4.88% Series, due September 15, 2030

 

 

90.0

 

 

 

—

 

7.90% Series, due September 15, 2030

 

 

30.0

 

 

 

30.0

 

5.12% Series, due September 15, 2032

 

 

60.0

 

 

 

—

 

3.68% Series, due September 15, 2032

 

 

50.0

 

 

 

50.0

 

4.80% Series, due February 15, 2033

 

 

400.0

 

 

 

400.0

 

6.00% Series, due May 1, 2034

 

 

99.3

 

 

 

99.3

 

5.15% Series, due August 15, 2034

 

 

320.0

 

 

 

320.0

 

6.15% Series, due June 1, 2036

 

 

54.5

 

 

 

54.5

 

4.63% Series, due August 15, 2043

 

 

99.9

 

 

 

99.9

 

4.23% Series, due September 15, 2047

 

 

70.0

 

 

 

70.0

 

3.30% Series, due June 1, 2051

 

 

305.0

 

 

 

305.0

 

4.38% Series, due September 15, 2057

 

 

50.0

 

 

 

50.0

 

Total principal of Spire Missouri long-term debt

 

 

1,968.0

 

 

 

1,818.0

 

Less: Unamortized discounts and debt issuance costs

 

 

(14.4

)

 

 

(14.6

)

Spire Missouri long-term debt, excluding current portion

 

$

1,953.6

 

 

$

1,803.4

 

Spire Alabama

 

 

 

 

 

 

3.21% Notes, due September 15, 2025

 

$

—

 

 

$

35.0

 

5.32% Notes, due October 15, 2029

 

 

90.0

 

 

 

90.0

 

2.88% Notes, due December 1, 2029

 

 

100.0

 

 

 

100.0

 

2.04% Notes, due December 15, 2030

 

 

150.0

 

 

 

150.0

 

5.41% Notes, due October 15, 2032

 

 

85.0

 

 

 

85.0

 

5.90% Notes, due January 15, 2037

 

 

45.0

 

 

 

45.0

 

4.31% Notes, due December 1, 2045

 

 

80.0

 

 

 

80.0

 

3.92% Notes, due January 15, 2048

 

 

45.0

 

 

 

45.0

 

4.64% Notes, due January 15, 2049

 

 

90.0

 

 

 

90.0

 

4.02% Notes, due January 15, 2058

 

 

30.0

 

 

 

30.0

 

Total principal of Spire Alabama long-term debt

 

 

715.0

 

 

 

750.0

 

Less: Unamortized discounts and debt issuance costs

 

 

(3.3

)

 

 

(3.7

)

Less: Current portion

 

 

—

 

 

 

(35.0

)

Spire Alabama long-term debt, excluding current portion

 

$

711.7

 

 

$

711.3

 

 

Maturities of long-term debt for Spire on a consolidated basis, Spire Missouri and Spire Alabama for the five fiscal years after September 30, 2025 are as follows:

 

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030

 

Spire

 

$

487.5

 

 

$

108.1

 

 

$

53.6

 

 

$

28.5

 

 

$

594.9

 

Spire Missouri

 

 

—

 

 

 

—

 

 

 

45.0

 

 

 

19.3

 

 

 

395.0

 

Spire Alabama

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

190.0

 

 

The long-term debt agreements of Spire, Spire Missouri and Spire Alabama contain customary financial covenants and default provisions. As of September 30, 2025, there were no events of default under these financial covenants.

Spire

At September 30, 2025, Spire had outstanding principal of long-term debt totaling $3,879.1, of which $1,968.0 was issued by Spire Missouri, $715.0 was issued by Spire Alabama and $1,196.1 was issued by Spire and other subsidiaries. All long-term debt bears fixed rates and is subject to changes in fair value as market interest rates change. However, increases and decreases in fair value would impact earnings and cash flows only if the Company were to reacquire any of these issues in the open market prior to maturity. Under GAAP applicable to the Utilities’ regulated operations, losses or gains on early redemption of long-term debt would typically be deferred as regulatory assets or regulatory liabilities and amortized over a future period. Interest expense shown on Spire’s consolidated statement of income is net of capitalized interest totaling $19.5, $17.0 and $8.6 for the years ended September 30, 2025, 2024 and 2023, respectively.

As indicated in Note 5, Shareholders’ Equity, Spire has a shelf registration statement on Form S-3 on file with the SEC for the issuance of equity and debt securities.

Spire Missouri

At September 30, 2025, Spire Missouri had outstanding principal of long-term debt totaling $1,968.0. All long-term debt bears fixed rates and is subject to changes in fair value as market interest rates change. Interest expense shown on Spire Missouri’s statement of comprehensive income is net of capitalized interest totaling $4.8, $4.6 and $3.1 for the years ended September 30, 2025, 2024 and 2023, respectively.

 

On October 23, 2025, Spire Missouri issued an aggregate principal amount of $200.0 of First Mortgage Bonds. The first tranche consisted of an aggregate principal amount of $150.0, bearing interest at 4.60% per annum and maturing on September 15, 2030. The second tranche consisted of an aggregate principal amount of $50.0, bears interest at 4.65% per annum and maturing on January 15, 2031. Interest is payable semi-annually on March 15 and September 15 of each year. The bonds are senior secured indebtedness of Spire Missouri and rank equally with all other existing and future senior secured indebtedness issued by Spire Missouri under its Mortgage and Deed of Trust. The bonds are secured by a first mortgage lien on substantially all the real properties of Spire Missouri, subject to limited exceptions. Spire Missouri used the proceeds for general corporate purposes.

As indicated in Note 5, Shareholders’ Equity, Spire Missouri has a shelf registration on Form S-3 on file with the SEC for issuance of equity and debt securities, which expires on May 7, 2028. Effective October 27, 2024, Spire Missouri was authorized by the MoPSC to issue conventional term loans, first mortgage bonds, unsecured debt, preferred stock and common stock in an aggregate amount not to exceed $850.0 any time from that date through December 31, 2027. Under this authorization, through October 23, 2025, Spire Missouri has issued $74.4 of common stock and $350 of first mortgage bonds. Approximately $426.0 remains available for issuance under this authorization.

Substantially all of Spire Missouri’s plant is subject to the liens of its first mortgage bonds. The mortgage contains several restrictions on Spire Missouri’s ability to pay cash dividends on its common stock, which are described in Note 5, Shareholders’ Equity.

Spire Alabama

At September 30, 2025, Spire Alabama had outstanding principal of fixed-rate long-term debt totaling $715.0. All long-term debt bears fixed rates and is subject to changes in fair value as market interest rates change. Interest expense shown on Spire Alabama’s statement of income is net of capitalized interest totaling $4.5, $1.8 and $2.3 for the years ended September 30, 2025, 2024 and 2023, respectively.

Spire Alabama has no standing authority to issue long-term debt and must petition the APSC for each planned issuance.
v3.25.3
Notes Payable and Credit Agreements
 12 Months Ended
Sep. 30, 2025
Debt Disclosure [Abstract]  
Notes Payable and Credit Agreements

7. NOTES PAYABLE AND CREDIT AGREEMENTS

Spire, Spire Missouri and Spire Alabama have a syndicated revolving credit facility pursuant to a loan agreement with 12 banks through October 11, 2029. The loan agreement has an aggregate credit commitment of $1,500.0, including sublimits of $525.0 for the Spire holding company, $700.0 for Spire Missouri and $275.0 for Spire Alabama. These sublimits may be reallocated from time to time among the three borrowers within the $1,500.0 aggregate commitment, with commitment fees and interest margins applied for each borrower relative to its credit rating. The Spire holding company may use its line to provide for the funding needs of various subsidiaries. The agreement also contains financial covenants limiting each borrower’s consolidated total debt, including short-term debt, to no more than 70% of its total capitalization. As defined in the line of credit, on September 30, 2025, total debt was less than 65% of total capitalization for each borrower. There were no borrowings against this credit facility as of September 30, 2025 and 2024.

Spire has a commercial paper program (“CP Program”) pursuant to which it may issue short-term, unsecured commercial paper notes. Amounts available under the CP Program may be borrowed, repaid and re-borrowed from time to time, with the aggregate face or principal amount of the notes outstanding under the CP Program at any time not to exceed $1,500.0. The notes may have maturities of up to 365 days from date of issue.

On January 3, 2024, Spire Missouri entered into a short-term loan agreement with several banks for a $200.0 unsecured term loan. Interest accrued at the one-month term secured overnight financing rate (“SOFR”) plus a SOFR adjustment of 0.10% per annum plus a margin of 0.90% per annum. Spire Missouri repaid $50.0 of this loan on April 5, 2024 and the remaining $150.0 balance on May 6, 2024.

Information about short-term borrowings, including Spire Missouri’s and Spire Alabama’s borrowings from Spire, is presented in the following table. As of September 30, 2025, $741.0 of Spire’s short-term borrowings were used to support lending to the Utilities.

 

 

 

Spire

 

 

Spire

 

 

Spire

 

 

 

 

 

 

(Parent Only)

 

 

Missouri

 

 

Alabama

 

 

Spire

 

 

 

CP

 

 

 

Spire

 

 

Spire

 

 

Consol-

 

 

 

Program

 

 

 

Note

 

 

Note

 

 

idated

 

Year Ended September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

Highest borrowings outstanding

 

$

1,348.0

 

 

 

$

615.0

 

 

$

130.6

 

 

$

1,348.0

 

Lowest borrowings outstanding

 

 

896.0

 

 

 

 

299.5

 

 

 

1.2

 

 

 

896.0

 

Weighted average borrowings

 

 

1,085.7

 

 

 

 

482.6

 

 

 

50.8

 

 

 

1,085.7

 

Weighted average interest rate

 

 

4.5

%

 

 

 

4.7

%

 

 

4.7

%

 

 

4.5

%

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

Borrowings outstanding

 

$

1,317.0

 

 

 

$

566.3

 

 

$

130.1

 

 

$

1,317.0

 

Weighted average interest rate

 

 

4.4

%

 

 

 

4.4

%

 

 

4.4

%

 

 

4.4

%

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

 

Borrowings outstanding

 

$

947.0

 

 

 

$

495.3

 

 

$

48.4

 

 

$

947.0

 

Weighted average interest rate

 

 

5.2

%

 

 

 

5.2

%

 

 

5.2

%

 

 

5.2

%

 

 

For additional information regarding the pending acquisition of Tennessee natural gas business from Piedmont Natural Gas, see Note 18 – Business Combinations, which is supported by a fully committed bridge financing facility discussed therein.
v3.25.3
Fair Value of Financial Instruments
 12 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]  
Fair Value of Financial Instruments

8. FAIR VALUE OF FINANCIAL INSTRUMENTS

The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis were as follows:

 

 

 

 

 

 

 

 

 

Classification of

 

 

 

 

 

 

 

 

 

Estimated Fair Value

 

 

 

 

 

 

 

 

 

Quoted

 

 

 

 

 

 

 

 

 

 

 

 

Prices in

 

 

Significant

 

 

 

 

 

 

 

 

 

Active

 

 

Observable

 

 

 

Carrying

 

 

Fair

 

 

Markets

 

 

Inputs

 

 

 

Amount

 

 

Value

 

 

(Level 1)

 

 

(Level 2)

 

Spire

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

5.7

 

 

$

5.7

 

 

$

5.7

 

 

$

—

 

Notes payable

 

 

1,317.0

 

 

 

1,317.0

 

 

 

—

 

 

 

1,317.0

 

Long-term debt, including current portion

 

 

3,856.9

 

 

 

3,691.5

 

 

 

—

 

 

 

3,691.5

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

4.5

 

 

$

4.5

 

 

$

4.5

 

 

$

—

 

Notes payable

 

 

947.0

 

 

 

947.0

 

 

 

—

 

 

 

947.0

 

Long-term debt, including current portion

 

 

3,746.4

 

 

 

3,600.3

 

 

 

—

 

 

 

3,600.3

 

Spire Missouri

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Notes payable - associated companies

 

$

566.3

 

 

$

566.3

 

 

$

—

 

 

$

566.3

 

Long-term debt

 

 

1,953.6

 

 

 

1,874.0

 

 

 

—

 

 

 

1,874.0

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Notes payable - associated companies

 

$

495.3

 

 

$

495.3

 

 

$

—

 

 

$

495.3

 

Long-term debt

 

 

1,803.4

 

 

 

1,736.9

 

 

 

—

 

 

 

1,736.9

 

Spire Alabama

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

1.9

 

 

$

1.9

 

 

$

1.9

 

 

$

—

 

Notes payable - associated companies

 

 

130.1

 

 

 

130.1

 

 

 

—

 

 

 

130.1

 

Long-term debt

 

 

711.7

 

 

 

675.9

 

 

 

—

 

 

 

675.9

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

1.5

 

 

$

1.5

 

 

$

1.5

 

 

$

—

 

Notes payable - associated companies

 

 

48.4

 

 

 

48.4

 

 

 

—

 

 

 

48.4

 

Long-term debt, including current portion

 

 

746.3

 

 

 

711.8

 

 

 

—

 

 

 

711.8

 
v3.25.3
Fair Value Measurements
 12 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]  
Fair Value Measurements

9. FAIR VALUE MEASUREMENTS

The information presented below categorizes the assets and liabilities in the balance sheets that are accounted for at fair value on a recurring basis in periods subsequent to initial recognition.

The mutual funds and bonds included in Level 1 are valued based on exchange-quoted market prices of individual securities.

Derivative instruments included in Level 1 are valued using quoted market prices on the NYMEX or the ICE and also certain natural gas commodity contracts. Derivative instruments classified in Level 2 include physical commodity derivatives and interest rate swaps that are valued using broker or dealer quotation services whose prices are derived principally from, or are corroborated by, observable market inputs. Also included in Level 2 are certain derivative instruments that have values that are similar to, and correlate with, quoted prices for exchange-traded instruments in active markets. Derivative instruments included in Level 3 are valued using generally unobservable inputs that are based upon the best information available and reflect management’s assumptions about how market participants would price the asset or liability. There were no Level 3 balances as of September 30, 2025 or 2024. The Company’s and the Utilities’ policy is to recognize transfers between the levels of the fair value hierarchy, if any, as of the beginning of the interim reporting period in which circumstances change or events occur to cause the transfer.

The mutual funds are included in “Other investments” on the Company’s balance sheets and in “Other Property and Investments” on Spire Missouri’s balance sheets. Changes in their recurring valuations are recorded as unrealized investment gains or losses in the corresponding periodic income statement. Derivative assets and liabilities, including receivables and payables associated with cash margin requirements, are presented net on the balance sheets when a legally enforceable netting agreement exist between the Company, Spire Missouri or Spire Alabama and the counterparty to the derivative contract. For additional information on derivative instruments, see Note 10, Derivative Instruments and Hedging Activities.

Spire

 

 

 

 

 

 

 

 

 

 

 

 

Effects of

 

 

 

 

 

 

Quoted

 

 

 

 

 

 

 

 

Netting

 

 

 

 

 

 

Prices

 

 

Significant

 

 

Significant

 

 

and Cash

 

 

 

 

 

 

in Active

 

 

Observable

 

 

Unobservable

 

 

Margin

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

Inputs

 

 

Receivables

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

(Level 3)

 

 

/Payables

 

 

Total

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

27.5

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

27.5

 

NYMEX/ICE natural gas contracts

 

 

2.9

 

 

 

—

 

 

 

—

 

 

 

(2.9

)

 

 

—

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

11.4

 

 

 

—

 

 

 

—

 

 

 

(11.4

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

44.8

 

 

 

—

 

 

 

(2.7

)

 

 

42.1

 

Other:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

 

27.0

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

27.0

 

U.S. bonds

 

 

23.5

 

 

 

—

 

 

 

—

 

 

 

 

 

 

23.5

 

Global Bonds

 

 

1.5

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

1.5

 

Interest rate swaps

 

 

—

 

 

 

10.0

 

 

 

—

 

 

 

—

 

 

 

10.0

 

Total

 

$

93.8

 

 

$

54.8

 

 

$

—

 

 

$

(17.0

)

 

$

131.6

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

25.9

 

 

$

—

 

 

$

—

 

 

$

(1.3

)

 

$

24.6

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

19.0

 

 

 

—

 

 

 

—

 

 

 

(19.0

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

16.7

 

 

 

—

 

 

 

(2.7

)

 

 

14.0

 

Total

 

$

44.9

 

 

$

16.7

 

 

$

—

 

 

$

(23.0

)

 

$

38.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

24.3

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

24.3

 

NYMEX/ICE natural gas contracts

 

 

3.4

 

 

 

—

 

 

 

—

 

 

 

(3.4

)

 

 

—

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

7.0

 

 

 

—

 

 

 

—

 

 

 

(7.0

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

46.0

 

 

 

—

 

 

 

(3.5

)

 

 

42.5

 

Other:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

 

17.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

17.9

 

U.S. bonds

 

 

21.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

21.9

 

Global Bonds

 

 

5.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

5.9

 

Interest rate swaps

 

 

—

 

 

 

0.8

 

 

 

—

 

 

 

—

 

 

 

0.8

 

Total

 

$

80.4

 

 

$

46.8

 

 

$

—

 

 

$

(13.9

)

 

$

113.3

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

13.6

 

 

$

—

 

 

$

—

 

 

$

(3.8

)

 

$

9.8

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

17.7

 

 

 

—

 

 

 

—

 

 

 

(17.7

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

24.5

 

 

 

—

 

 

 

(3.5

)

 

 

21.0

 

Other:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate swaps

 

 

—

 

 

 

1.5

 

 

 

—

 

 

 

—

 

 

 

1.5

 

Total

 

$

31.3

 

 

$

26.0

 

 

$

—

 

 

$

(25.0

)

 

$

32.3

 

 

Spire Missouri

 

 

 

 

 

 

 

 

 

 

 

 

Effects of

 

 

 

 

 

 

Quoted

 

 

 

 

 

 

 

 

Netting

 

 

 

 

 

 

Prices

 

 

Significant

 

 

Significant

 

 

and Cash

 

 

 

 

 

 

in Active

 

 

Observable

 

 

Unobservable

 

 

Margin

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

Inputs

 

 

Receivables

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

(Level 3)

 

 

/Payables

 

 

Total

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

27.5

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

27.5

 

NYMEX/ICE natural gas contracts

 

 

2.9

 

 

 

—

 

 

 

—

 

 

 

(2.9

)

 

 

—

 

Total

 

$

30.4

 

 

$

—

 

 

$

—

 

 

$

(2.9

)

 

$

27.5

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

25.9

 

 

$

—

 

 

$

—

 

 

$

(1.3

)

 

$

24.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

24.3

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

24.3

 

NYMEX/ICE natural gas contracts

 

 

3.4

 

 

 

—

 

 

 

—

 

 

 

(3.4

)

 

 

—

 

Total

 

$

27.7

 

 

$

—

 

 

$

—

 

 

$

(3.4

)

 

$

24.3

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

13.6

 

 

$

—

 

 

$

—

 

 

$

(3.8

)

 

$

9.8

 

 

Spire Alabama

Spire Alabama occasionally utilizes a gasoline derivative program to stabilize the cost of fuel used in operations. As of September 30, 2025 and September 30, 2024, there were no gasoline derivatives outstanding.
v3.25.3
Derivative Instruments and Hedging Activities
 12 Months Ended
Sep. 30, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Derivative Instruments and Hedging Activities

10. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

Spire

Spire Missouri has a risk management policy to utilize various derivatives, including futures contracts, exchange-traded options and swaps for the explicit purpose of managing price risk associated with purchasing and delivering natural gas on a regular basis to customers in accordance with its tariffs. The objective of this policy is to limit Spire Missouri’s exposure to natural gas price volatility and to manage, hedge and mitigate substantial price risk. Further discussion of this policy can be found in the Spire Missouri section.

From time to time Spire Missouri and Spire Alabama purchase NYMEX futures and options contracts to help stabilize operating costs associated with forecasted purchases of gasoline and diesel fuels used to power vehicles and equipment. Further information on these derivatives can be found in the Spire Missouri and Spire Alabama sections, respectively.

In the course of its business, Spire’s gas marketing subsidiary, Spire Marketing enters into commitments associated with the purchase or sale of natural gas. Certain of Spire Marketing’s derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of ASC Topic 815 and are accounted for as executory contracts on an accrual basis. Any of Spire Marketing’s derivative natural gas contracts that are not designated as normal purchases or normal sales are accounted for at fair value. At September 30, 2025, the fair values of 278.2 million MMBtu of non-exchange-traded natural gas commodity contracts were reflected in the Consolidated Balance Sheet. Of these contracts, 236.7 million MMBtu will settle during fiscal 2026, and 29.7 million MMBtu, 8.2 million MMBtu, and 3.4 million MMBtu, will settle during fiscal years 2027, 2028, and 2029, respectively. A total of 0.2 million MMBtu will settle in the years 2029-2031. These contracts have not been designated as hedges; therefore, changes in the fair value of these contracts are reported in earnings each period.

Furthermore, Spire Marketing manages the price risk associated with its fixed-priced commitments by either closely matching the offsetting physical purchase or sale of natural gas at fixed prices or through the use of NYMEX or ICE futures, swap, and option contracts to lock in margins.

At September 30, 2025, Spire Marketing’s unmatched fixed-price positions were not material to Spire’s financial position or results of operations. Spire Marketing’s NYMEX and ICE natural gas futures, swap and option contracts used to lock in margins may be designated as cash flow hedges of forecasted transactions for financial reporting purposes.

Spire enters into cash flow hedges through the execution of interest rate swap contracts to protect itself against adverse movements in interest rates. At September 30, 2025, the following swaps were outstanding:

 

Period Originated

 

Contract
Hedge Term
(Years)

 

 

Notional
Amount

 

 

Fixed
Interest
Rate

 

 

Fiscal 2025
Mark-to-
Market Gain

 

Quarter 3, fiscal 2023

 

 

10

 

 

$

25.0

 

 

 

3.018

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.400

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.525

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.535

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.450

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.541

%

 

 

0.7

 

Quarter 4, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.552

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.426

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.577

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.450

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.350

%

 

 

0.8

 

Quarter 1, fiscal 2025

 

1.5

 

 

 

125.0

 

 

 

3.567

%

 

 

0.2

 

Quarter 1, fiscal 2025

 

1.5

 

 

 

225.0

 

 

 

3.567

%

 

 

0.4

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.580

%

 

 

0.3

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.611

%

 

 

0.3

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.657

%

 

 

0.3

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.763

%

 

 

0.5

 

 

 

 

 

$

725.0

 

 

 

 

 

$

10.7

 

 

As of September 30, 2025, the Company has recorded through other comprehensive income a cumulative mark-to-market net asset of $10.0 on open swaps.

The Company’s and Spire Missouri’s exchange-traded/cleared derivative instruments consist primarily of NYMEX and ICE positions. The NYMEX is the primary national commodities exchange on which natural gas derivatives are traded. Open NYMEX and ICE natural gas futures and swap positions at September 30, 2025 and 2024 were as follows:

 

 

 

September 30, 2025

 

 

September 30, 2024

 

Gas Marketing

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

Natural gas futures purchased

 

 

48.0

 

 

 

48

 

 

 

56.0

 

 

 

48

 

Natural gas options purchased, net

 

 

9.9

 

 

 

15

 

 

 

3.8

 

 

 

15

 

Natural gas basis swaps purchased

 

 

24.7

 

 

 

39

 

 

 

32.4

 

 

 

39

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility

 

 

 

 

 

 

 

 

 

 

 

 

Natural gas futures purchased

 

 

32.3

 

 

 

12.0

 

 

 

34.6

 

 

 

12

 

 

At September 30, 2025, Spire Missouri also had 9.78 million MMBtu of other price mitigation in place through the use of NYMEX natural gas option-based strategies.

Derivative instruments designated as cash flow hedges of forecasted transactions are recognized on the balance sheets of the Company at fair value, and the change in fair value of the effective portion of these hedge instruments is recorded, net of income tax, in other comprehensive income or loss ("OCI"). AOCI is a component of Total Common Stock Equity. Amounts are reclassified from AOCI into earnings when the hedged items affect net income, using the same revenue or expense category that the hedged item impacts. Based on market prices at September 30, 2025, it is expected that $2.6 of net gains will be reclassified into the Consolidated Statements of Income of the Company during the next twelve months.

Cash flows from hedging transactions are classified in the same category as the cash flows from the items that are being hedged in the Consolidated Statements of Cash Flows.

 

Effect of Derivative Instruments on the Consolidated Statements of Income and Comprehensive Income

 

 

 

Location of Gain (Loss)

 

 

 

 

 

 

 

 

 

 

 

Recorded in Income

 

2025

 

 

2024

 

 

2023

 

Derivatives in Cash Flow Hedging Relationships

 

 

 

 

 

 

 

 

 

Portion of gain (loss) recognized in OCI on derivatives:

 

 

 

 

 

 

 

 

 

Interest rate swaps

 

 

 

$

12.8

 

 

$

(15.9

)

 

$

20.1

 

Portion of gain reclassified from AOCI to income:

 

 

 

 

 

 

 

 

 

Interest rate swaps

 

Interest Expense

 

$

5.1

 

 

$

11.1

 

 

$

2.4

 

 

 

 

 

 

 

 

 

 

 

 

Derivatives Not Designated as Hedging Instruments*

 

 

 

 

 

 

 

 

 

(Loss) gain recognized in income on derivatives:

 

 

 

 

 

 

 

 

 

Gas / diesel futures

 

Other Income (Expense), Net

 

$

—

 

 

$

(0.3

)

 

$

0.3

 

Natural gas commodity contracts

 

Operating Expenses: Natural Gas

 

 

(6.5

)

 

 

12.5

 

 

 

18.0

 

NYMEX / ICE natural gas contracts

 

Operating Expenses: Natural Gas

 

 

(3.1

)

 

 

(16.3

)

 

 

(35.0

)

Total

 

 

 

$

(9.6

)

 

$

(4.1

)

 

$

(16.7

)

 

* Gains and losses on Spire Missouri’s natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Missouri Utilities’ PGA clauses and initially recorded as regulatory assets or regulatory liabilities. These gains and losses are excluded from the table above because they have no direct impact on the statements of income. Such amounts are recognized in the statements of income as a component of natural gas operating expenses when they are recovered through the PGA clause and reflected in customer billings.

 

Fair Value of Derivative Instruments in the Consolidated Balance Sheets

 

 

 

Derivative Assets*

 

 

Derivative Liabilities*

 

September 30, 2025

 

Balance Sheet Location

 

Fair
Value

 

 

Balance Sheet Location

 

Fair
Value

 

Derivatives designated as hedging instruments

 

 

 

 

 

 

 

 

Other: Interest rate swaps

 

Current Assets: Other

 

$

10.0

 

 

Current Liabilities: Other

 

$

—

 

Subtotal

 

 

 

 

10.0

 

 

 

 

 

—

 

 

 

 

 

 

 

 

 

 

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

 

2.9

 

 

Current Liabilities: Other

 

 

25.9

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

NYMEX / ICE natural gas contracts

 

Current Assets: Other

 

 

11.3

 

 

Current Liabilities: Other

 

 

17.7

 

 

Deferred Charges and Other Assets: Other

 

 

0.1

 

 

Deferred Credits and Other Liabilities: Other

 

 

1.3

 

Natural gas commodity

 

Current Assets: Other

 

 

42.8

 

 

Current Liabilities: Other

 

 

15.6

 

 

Deferred Charges and Other Assets: Other

 

 

2.0

 

 

Deferred Credits and Other Liabilities: Other

 

 

1.1

 

Subtotal

 

 

 

 

59.1

 

 

 

 

 

61.6

 

Total derivatives

 

 

 

$

69.1

 

 

 

 

$

61.6

 

 

 

 

 

 

 

 

 

 

 

September 30, 2024

 

 

 

 

 

 

 

 

 

 

Derivatives designated as hedging instruments

 

 

 

 

 

 

 

 

Other: Interest rate swaps

 

Current Assets: Other

 

$

0.8

 

 

Current Liabilities: Other

 

$

1.5

 

Subtotal

 

 

 

 

0.8

 

 

 

 

 

1.5

 

 

 

 

 

 

 

 

 

 

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

 

3.4

 

 

Current Liabilities: Other

 

 

13.6

 

Gasoline and heating oil contracts

 

Current Assets: Other

 

 

—

 

 

 

 

 

—

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

NYMEX / ICE natural gas contracts

 

Current Assets: Other

 

 

6.2

 

 

Current Liabilities: Other

 

 

13.7

 

 

Deferred Charges and Other Assets: Other

 

 

0.8

 

 

Deferred Credits and Other Liabilities: Other

 

 

4.0

 

Natural gas commodity

 

Current Assets: Other

 

 

42.1

 

 

Current Liabilities: Other

 

 

19.8

 

 

Deferred Charges and Other Assets: Other

 

 

3.9

 

 

Deferred Credits and Other Liabilities: Other

 

 

4.7

 

Subtotal

 

 

 

 

56.4

 

 

 

 

 

55.8

 

Total derivatives

 

 

 

$

57.2

 

 

 

 

$

57.3

 

 

 

* The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of the Company’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.

Following is a reconciliation of the amounts in the tables above to the amounts presented in the consolidated balance sheets:

 

 

 

2025

 

 

2024

 

Fair value of derivative assets presented above

 

$

69.1

 

 

$

57.2

 

Fair value of cash margin receivable offset with derivatives

 

 

6.0

 

 

 

11.1

 

Netting of assets and liabilities with the same counterparty

 

 

(23.0

)

 

 

(25.0

)

Total

 

$

52.1

 

 

$

43.3

 

Derivative Instrument Assets, per Consolidated Balance Sheets:

 

 

 

 

 

 

Current Assets: Other

 

$

50.1

 

 

$

39.5

 

Deferred Charges and Other Assets: Other

 

 

2.0

 

 

 

3.8

 

Total

 

$

52.1

 

 

$

43.3

 

 

 

 

 

 

 

Fair value of derivative liabilities presented above

 

$

61.6

 

 

$

57.3

 

Netting of assets and liabilities with the same counterparty

 

 

(23.0

)

 

 

(25.0

)

Total

 

$

38.6

 

 

$

32.3

 

Derivative Instrument Liabilities, per Consolidated Balance Sheets:

 

 

 

 

 

 

Current Liabilities: Other

 

$

37.5

 

 

$

27.6

 

Deferred Credits and Other Liabilities: Other

 

 

1.1

 

 

 

4.7

 

Total

 

$

38.6

 

 

$

32.3

 

 

Spire Missouri

Spire Missouri has a risk management policy to utilize various derivatives, including futures contracts, exchange-traded options, swaps and over-the-counter instruments for the explicit purpose of managing price risk associated with purchasing and delivering natural gas on a regular basis to customers in accordance with its tariffs. The objective of this policy is to limit Spire Missouri’s exposure to natural gas price volatility and to manage, hedge and mitigate substantial price risk. This policy strictly prohibits speculation and permits Spire Missouri to hedge current physical natural gas purchase commitments or forecasted or anticipated future peak (maximum) physical need for natural gas delivered. Costs and cost reductions, including carrying costs, associated with Spire Missouri’s use of natural gas derivative instruments are allowed to be passed on to Spire Missouri customers through the operation of its PGA clause, through which the MoPSC allows Spire Missouri to recover gas supply costs, subject to prudence review by the MoPSC. Accordingly, Spire Missouri does not expect any adverse earnings impact as a result of the use of these derivative instruments.

Spire Missouri does not designate these instruments as hedging instruments for financial reporting purposes because gains or losses associated with the use of these derivative instruments are deferred and recorded as regulatory assets or regulatory liabilities pursuant to ASC Topic 980, Regulated Operations, and, as a result, have no direct impact on the statements of income.

The timing of the operation of the PGA clause may cause interim variations in short-term cash flows, because Spire Missouri is subject to cash margin requirements associated with changes in the values of these instruments. Nevertheless, carrying costs associated with such requirements are recovered through the PGA clause.

From time to time, Spire Missouri purchases NYMEX futures and options contracts to help stabilize operating costs associated with forecasted purchases of gasoline and diesel fuels used to power vehicles and equipment used in the course of its business. The gains and losses on these contracts are not subject to Spire Missouri’s PGA clause. At September 30, 2025, Spire Missouri did not have a material amount of gasoline futures contracts outstanding.

Derivative instruments designated as cash flow hedges of forecasted transactions are recognized on the balance sheets at fair value and the change in the fair value of the effective portion of these hedge instruments is recorded, net of income tax, in OCI. AOCI is a component of Total Common Stock Equity. Amounts are reclassified from AOCI into earnings when the hedged items affect net income, using the same revenue or expense category that the hedged item impacts. As in both 2024 and 2023, there will be no reclassifications into the statements of income during fiscal 2026. Cash flows from hedging transactions are classified in the same category as the cash flows from the items that are being hedged in the statements of cash flows.

Spire Missouri’s derivative instruments consist primarily of NYMEX positions. The NYMEX is the primary national commodities exchange on which natural gas derivatives are traded. Open NYMEX natural gas futures positions at September 30, 2025 and 2024 were as follows:

 

 

 

September 30, 2025

 

 

September 30, 2024

 

 

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

Natural gas futures purchased

 

 

32.3

 

 

 

12

 

 

 

34.6

 

 

 

12

 

 

At September 30, 2025, Spire Missouri had also had 9.78 million MMBtu of other price mitigation in place through the use of NYMEX natural gas option-based strategies.

Gains and losses on Spire Missouri’s natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Spire Missouri’s PGA clauses and initially recorded as regulatory assets or regulatory liabilities. Such amounts are recognized in the statements of income as a component of natural gas operating expenses when they are recovered through the PGA clause and reflected in customer billings.

 

Fair Value of Derivative Instruments in the Balance Sheets

 

 

 

Derivative Assets*

 

 

Derivative Liabilities*

 

September 30, 2025

 

Balance Sheet Location

 

Fair
Value

 

 

Balance Sheet Location

 

Fair
Value

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

$

2.9

 

 

Current Liabilities: Other

 

$

25.9

 

Total derivatives

 

 

 

$

2.9

 

 

 

 

$

25.9

 

 

 

 

 

 

 

 

 

 

 

September 30, 2024

 

 

 

 

 

 

 

 

 

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

$

3.4

 

 

Current Liabilities: Other

 

$

13.6

 

Gasoline and heating oil contracts

 

Current Assets: Other

 

 

—

 

 

 

 

 

—

 

Total derivatives

 

 

 

$

3.4

 

 

 

 

$

13.6

 

 

* The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of Spire Missouri’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.

Following is a reconciliation of the amounts in the tables above to the amounts presented in Spire Missouri’s balance sheets:

 

 

 

2025

 

 

2024

 

Fair value of derivative assets presented above

 

$

2.9

 

 

$

3.4

 

Fair value of cash margin receivable offset with derivatives

 

 

(1.6

)

 

 

0.4

 

Netting of assets and liabilities with the same counterparty

 

 

(1.3

)

 

 

(3.8

)

Total

 

$

—

 

 

$

—

 

 

 

 

 

 

 

Fair value of derivative liabilities presented above

 

$

25.9

 

 

$

13.6

 

Netting of assets and liabilities with the same counterparty

 

 

(1.3

)

 

 

(3.8

)

Total

 

 

24.6

 

 

 

9.8

 

 

 

 

 

 

 

Derivative Instrument Liabilities, per Balance Sheets:

 

 

 

 

 

 

Current Liabilities: Other

 

$

24.6

 

 

$

9.8

 

Deferred Credits and Other Liabilities: Other

 

 

-

 

 

 

—

 

Total

 

$

24.6

 

 

$

9.8

 

 

Spire Alabama

Spire Alabama periodically employs a gasoline derivative program to help stabilize operating costs associated with forecasted purchases of gasoline and diesel fuels used to power vehicles and equipment used in the course of its business. The gains or losses on these derivative instruments are not subject to Spire Alabama’s GSA rider. There were no such contracts outstanding as of September 30, 2025 and 2024.
v3.25.3
Concentrations of Credit Risk
 12 Months Ended
Sep. 30, 2025
Risks and Uncertainties [Abstract]  
Concentrations of Credit Risk

11. CONCENTRATIONS OF CREDIT RISK

Spire’s Gas Utility segment serves 1.7 million customers in three states across multiple rate classes resulting in a significant amount of revenue diversity. Credit risk is mitigated by the high percentage of residential customers as well as the geographic diversity of the Utilities, though customers for each of the Utilities are concentrated in a single state.

Spire Marketing’s accounts receivable attributable to utility companies and their marketing affiliates totaled $52.3 at September 30, 2025. The concentration of transactions with these counterparties has the potential to affect the Company’s overall exposure to credit risk, either positively or negatively, in that customers in this group may be affected similarly by changes in economic, industry, or other conditions. Spire Marketing also has concentrations of credit risk with certain individually significant counterparties. At September 30, 2025, the amounts included in accounts receivable from its five largest counterparties (in terms of net accounts receivable exposure) totaled $25.6. Three of these five counterparties are investment-grade-rated integrated utilities, one is a liquefied natural gas project facility with a senior debt issue rating one notch below investment-grade with a positive outlook, and one is a utility marketing affiliate which is not rated but whose owners are all investment-grade public power companies.

To manage these risks, Spire Marketing has established procedures to determine the creditworthiness of its counterparties. These procedures include obtaining credit ratings and credit reports, analyzing counterparty financial statements to assess financial condition, and considering the industry environment in which the counterparty operates. This information is monitored on an ongoing basis. In some instances, Spire Marketing may require credit assurances such as prepayments, letters of credit, or parental guaranties. In addition, Spire Marketing may enter into netting arrangements to mitigate credit risk with counterparties in the energy industry with whom it conducts both sales and purchases of natural gas. Where there is no netting arrangement, Spire Marketing records accounts receivable, accounts payable, and prepayments for physical sales and purchases of natural gas on a gross basis. Sales are typically made on an unsecured credit basis with payment due the month following delivery. Accounts receivable amounts are closely monitored and provisions for uncollectible amounts are accrued when losses are probable.
v3.25.3
Income Taxes
 12 Months Ended
Sep. 30, 2025
Income Tax Disclosure [Abstract]  
Income Taxes

12. INCOME TAXES

The Company, Spire Missouri, and Spire Alabama are subject to federal income tax as well as income tax in various state and local jurisdictions. Spire files a consolidated federal income tax return and various state income tax returns and allocates income taxes to Spire Missouri, Spire Alabama and its other subsidiaries as if each entity were a separate taxpayer.

The provision for income taxes during the fiscal years ended September 30, 2025, 2024, and 2023 was as follows:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Federal:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

1.7

 

 

$

0.2

 

 

$

0.7

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

Deferred

 

 

46.3

 

 

 

46.1

 

 

 

30.4

 

 

 

12.4

 

 

 

13.5

 

 

 

10.1

 

 

 

22.9

 

 

 

21.7

 

 

 

15.8

 

Investment tax credits

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

—

 

 

 

—

 

 

 

—

 

State and local:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

 

0.7

 

 

 

1.5

 

 

 

1.2

 

 

 

0.2

 

 

 

0.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Deferred

 

 

11.2

 

 

 

11.1

 

 

 

6.7

 

 

 

1.4

 

 

 

1.5

 

 

 

1.7

 

 

 

5.5

 

 

 

5.2

 

 

 

4.5

 

Total income tax expense

 

$

59.7

 

 

$

58.7

 

 

$

38.8

 

 

$

13.8

 

 

$

15.7

 

 

$

11.6

 

 

$

28.4

 

 

$

26.9

 

 

$

20.3

 

 

The effective income tax rate varied from the federal statutory income tax rate for each year due to the following:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Federal income tax statutory rate

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

State and local income taxes, net of federal
   income tax benefits

 

 

3.7

 

 

 

3.7

 

 

 

3.7

 

 

 

2.6

 

 

 

2.6

 

 

 

2.6

 

 

 

4.1

 

 

 

4.1

 

 

 

4.1

 

Certain expenses capitalized on books and
   deducted on tax return

 

 

(1.1

)

 

 

(1.2

)

 

 

(1.4

)

 

 

(2.5

)

 

 

(2.7

)

 

 

(2.7

)

 

 

—

 

 

 

—

 

 

 

—

 

Tax credits *

 

 

(0.8

)

 

 

(0.9

)

 

 

(3.3

)

 

 

(1.1

)

 

 

(1.1

)

 

 

(4.2

)

 

 

(0.3

)

 

 

(0.3

)

 

 

(1.9

)

Amortization of excess deferred taxes

 

 

(3.1

)

 

 

(3.3

)

 

 

(5.1

)

 

 

(7.0

)

 

 

(7.4

)

 

 

(7.7

)

 

 

0.1

 

 

 

0.2

 

 

 

0.2

 

Taxes related to prior years

 

 

(1.3

)

 

 

—

 

 

 

—

 

 

 

(2.9

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Other items – net

 

 

(0.4

)

 

 

(0.3

)

 

 

0.2

 

 

 

(0.4

)

 

 

(0.7

)

 

 

—

 

 

 

0.1

 

 

 

0.1

 

 

 

0.1

 

Effective income tax rate

 

 

18.0

 %

 

 

19.0

 %

 

 

15.1

 %

 

 

9.7

 %

 

 

11.7

 %

 

 

9.0

 %

 

 

25.0

 %

 

 

25.1

 %

 

 

23.5

 %

 

* In 2023, the Company completed a research and development study which encompassed fiscal years 2014 to 2022.

The significant items comprising the net deferred tax liability or asset as of September 30 were as follows:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Deferred tax assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Operating losses

 

$

150.1

 

 

$

182.2

 

 

$

1.5

 

 

$

24.7

 

 

$

146.1

 

 

$

153.0

 

Goodwill

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

29.7

 

 

 

44.4

 

Pension and other postretirement benefits

 

 

52.6

 

 

 

58.6

 

 

 

36.0

 

 

 

39.3

 

 

 

14.8

 

 

 

17.1

 

Regulatory amount due to customers, net

 

 

23.9

 

 

 

27.1

 

 

 

21.4

 

 

 

24.5

 

 

 

—

 

 

 

2.3

 

Reserves not currently deductible

 

 

24.9

 

 

 

0.5

 

 

 

—

 

 

 

—

 

 

 

3.4

 

 

 

2.9

 

Other

 

 

73.5

 

 

 

43.3

 

 

 

16.7

 

 

 

12.3

 

 

 

6.0

 

 

 

2.1

 

Total deferred tax assets

 

 

325.0

 

 

 

311.7

 

 

 

75.6

 

 

 

100.8

 

 

 

200.0

 

 

 

221.8

 

Deferred tax liabilities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Relating to property

 

 

(912.3

)

 

 

(842.2

)

 

 

(572.6

)

 

 

(531.2

)

 

 

(238.1

)

 

 

(230.0

)

Regulatory pension and other postretirement
   benefits

 

 

(54.4

)

 

 

(60.8

)

 

 

(27.2

)

 

 

(33.8

)

 

 

(24.0

)

 

 

(25.6

)

Deferred gas costs

 

 

(10.7

)

 

 

(19.9

)

 

 

(8.2

)

 

 

(17.7

)

 

 

—

 

 

 

—

 

Other ***

 

 

(235.0

)

 

 

(197.2

)

 

 

(66.3

)

 

 

(85.7

)

 

 

(2.0

)

 

 

(2.1

)

Total deferred tax liabilities

 

 

(1,212.4

)

 

 

(1,120.1

)

 

 

(674.3

)

 

 

(668.4

)

 

 

(264.1

)

 

 

(257.7

)

Net deferred tax (liability) asset

 

$

(887.4

)

 

$

(808.4

)

 

$

(598.7

)

 

$

(567.6

)

 

$

(64.1

)

 

$

(35.9

)

 

*** For Spire, Other consists primarily of goodwill-related liabilities.

As indicated in Note 1, Summary of Significant Accounting Policies, the Company’s regulated operations accounting for income taxes is impacted by ASC Topic 980, Regulated Operations.

 

On April 14, 2023, the IRS issued Revenue Procedure 2023-15 that provides a safe harbor method of accounting that taxpayers may use to determine whether to deduct or capitalize expenditures to repair, maintain, replace, or improve natural gas transmission and distribution property. Under the revenue procedure, the method of accounting will depend on the property’s classification as linear transmission property, linear distribution property, or non-linear property. The revenue procedure may be adopted in tax years ending after May 1, 2023. The Company adopted the revenue procedure for Spire Alabama, Spire Gulf, and Spire Mississippi, with the filing of its tax return for the year ended September 30, 2024. The Company is still evaluating the revenue procedure for Spire Missouri.

In assessing whether deferred tax assets are realizable, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Management considers all significant available positive and negative evidence, including the existence of losses in recent years, the timing of deferred tax liability reversals, projected future taxable income, taxable income in carryback years, and tax planning strategies to assess the need for a valuation allowance. Based upon this evidence, management believes it is more likely than not the Company, Spire Missouri and Spire Alabama will realize the benefits of these deferred tax assets.

As of September 30, 2025, Spire, and on a separate company basis, Spire Missouri and Spire Alabama, had carryforwards as shown below.

 

 

 

Spire

 

 

Spire
Missouri

 

 

Spire
Alabama

 

Federal and state loss carryforwards

 

$

646.1

 

 

$

9.7

 

 

$

583.3

 

Tax credit carryforwards

 

 

18.9

 

 

 

8.8

 

 

 

2.7

 

 

For federal tax purposes, Spire Missouri’s and Spire Alabama’s loss carryforwards may be utilized against income from another member of the consolidated group. The loss carryforwards begin to expire in fiscal 2030 for certain state purposes and fiscal 2037 for federal and other state purposes. The tax credit carryforwards are expected to be utilized prior to their expiration.

The Company, Spire Missouri and Spire Alabama recognize the tax benefit from a tax position only if it is at least more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. Unrecognized tax benefits are reported as a reduction of a deferred tax asset for an operating loss carryforward to the extent the recognition of the benefit would impact the operating loss carryforward, pursuant to ASU 2013-11. The following table presents a reconciliation of the beginning and ending balances of unrecognized tax benefits.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Unrecognized tax benefits, beginning of year

 

$

26.3

 

 

$

23.8

 

 

$

19.6

 

 

$

25.3

 

 

$

22.9

 

 

$

19.3

 

 

$

0.3

 

 

$

0.3

 

 

$

—

 

Increases related to tax positions taken in
   current year

 

 

0.6

 

 

 

2.6

 

 

 

4.2

 

 

 

0.2

 

 

 

2.4

 

 

 

3.6

 

 

 

—

 

 

 

—

 

 

 

0.3

 

Decreases related to tax positions taken in prior years

 

 

(24.2

)

 

 

—

 

 

 

—

 

 

 

(24.2

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Reductions due to lapse of applicable statute
   of limitations

 

 

—

 

 

 

(0.1

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Unrecognized tax benefits, end of year

 

$

2.7

 

 

$

26.3

 

 

$

23.8

 

 

$

1.3

 

 

$

25.3

 

 

$

22.9

 

 

$

0.3

 

 

$

0.3

 

 

$

0.3

 

 

As of September 30, 2025 and 2024, the amounts of unrecognized tax benefits which, if recognized, would affect the effective tax rate were $2.7 and $6.2, respectively, for the Company, $1.3 and $5.3, respectively, for Spire Missouri, and $0.3 and $0.3, respectively, for Spire Alabama. It is reasonably possible that events will occur in the next 12 months that could increase or decrease the amount of the unrecognized tax benefits. The Company, Spire Missouri, and Spire Alabama do not expect that any such change will be significant to the balance sheets and results of operations.

The Company, Spire Missouri, and Spire Alabama record potential interest and penalties related to uncertain tax positions as interest expense and other income deductions, respectively. As of September 30, 2025 and 2024, interest accrued associated with uncertain tax positions was de minimis, and no penalties were accrued.

The Company, Spire Missouri, and Spire Alabama are no longer subject to examination for fiscal years prior to 2022, except to the extent the net operating losses from prior years are reviewed.

On July 4, 2025, the One Big Beautiful Bill Act (the Act) was signed into law. The Company is evaluating the impact of the Act and believes it will not have a material impact on the Company’s financial position, results of operations or cash flow. For fiscal 2025, the impact was not material.
v3.25.3
Pension Plans and Other Postretirement Benefits
 12 Months Ended
Sep. 30, 2025
Retirement Benefits [Abstract]  
Pension Plans and Other Postretirement Benefits

13. PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS

Pension Plans

Spire and the Utilities maintain pension plans for their employees. Spire Missouri and Spire Alabama have non-contributory, defined benefit, trusteed forms of pension plans covering the majority of their employees. Qualified plan assets are comprised of mutual and commingled funds consisting of U.S. equities with varying strategies, global equities, alternative investments, and fixed income investments.

The net periodic pension cost includes components shown in the following table. The components other than the service costs and regulatory adjustment are presented in “Other Income, Net” in the income statement, except for Spire Alabama’s losses on lump-sum settlements. Such losses are capitalized in regulatory balances and amortized over the remaining actuarial life of individuals in the plan, and that amortization is presented in “Other Income, Net.”

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Service cost – benefits earned during
   the period

 

$

17.6

 

 

$

15.7

 

 

$

16.3

 

 

$

11.4

 

 

$

10.4

 

 

$

11.4

 

 

$

5.5

 

 

$

4.6

 

 

$

4.2

 

Interest cost on projected benefit
   obligation

 

 

23.5

 

 

 

26.7

 

 

 

25.1

 

 

 

15.8

 

 

 

18.9

 

 

 

17.8

 

 

 

5.1

 

 

 

5.1

 

 

 

4.8

 

Expected return on plan assets

 

 

(25.9

)

 

 

(24.8

)

 

 

(24.5

)

 

 

(17.6

)

 

 

(17.0

)

 

 

(18.0

)

 

 

(5.3

)

 

 

(4.8

)

 

 

(3.5

)

Amortization of prior service credit

 

 

(4.5

)

 

 

(4.5

)

 

 

(4.5

)

 

 

(1.9

)

 

 

(1.9

)

 

 

(1.9

)

 

 

(2.4

)

 

 

(2.4

)

 

 

(2.4

)

Amortization of actuarial loss

 

 

6.5

 

 

 

6.4

 

 

 

6.6

 

 

 

4.1

 

 

 

5.9

 

 

 

6.1

 

 

 

2.4

 

 

 

1.0

 

 

 

0.9

 

Special termination benefits

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Loss on lump-sum settlements and
   curtailments

 

 

0.4

 

 

 

12.9

 

 

 

9.7

 

 

 

0.4

 

 

 

12.9

 

 

 

0.6

 

 

 

—

 

 

 

—

 

 

 

9.1

 

Subtotal

 

 

17.6

 

 

 

35.0

 

 

 

28.7

 

 

 

12.2

 

 

 

31.8

 

 

 

16.0

 

 

 

5.3

 

 

 

3.5

 

 

 

13.1

 

Regulatory adjustment

 

 

36.3

 

 

 

18.4

 

 

 

26.3

 

 

 

29.6

 

 

 

10.8

 

 

 

27.1

 

 

 

5.8

 

 

 

6.7

 

 

 

(1.7

)

Net pension cost

 

$

53.9

 

 

$

53.4

 

 

$

55.0

 

 

$

41.8

 

 

$

42.6

 

 

$

43.1

 

 

$

11.1

 

 

$

10.2

 

 

$

11.4

 

 

Other changes in plan assets and pension benefit obligations recognized in other comprehensive income or loss include the following:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Current year actuarial (gain) loss

 

$

(11.9

)

 

$

8.8

 

 

$

14.5

 

 

$

(9.9

)

 

$

(0.9

)

 

$

5.7

 

 

$

(0.8

)

 

$

8.5

 

 

$

9.0

 

Amortization of actuarial loss

 

 

(6.5

)

 

 

(6.4

)

 

 

(6.6

)

 

 

(4.1

)

 

 

(5.9

)

 

 

(6.1

)

 

 

(2.4

)

 

 

(1.0

)

 

 

(0.9

)

Acceleration of loss recognized due to
   settlement

 

 

(0.4

)

 

 

(12.9

)

 

 

(9.7

)

 

 

(0.4

)

 

 

(12.9

)

 

 

(0.6

)

 

 

—

 

 

 

—

 

 

 

(9.1

)

Current year service credit

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Amortization of prior service credit

 

 

4.5

 

 

 

4.5

 

 

 

4.5

 

 

 

1.9

 

 

 

1.9

 

 

 

1.9

 

 

 

2.4

 

 

 

2.4

 

 

 

2.4

 

Subtotal

 

 

(14.3

)

 

 

(5.8

)

 

 

2.7

 

 

 

(12.5

)

 

 

(17.6

)

 

 

0.9

 

 

 

(0.8

)

 

 

9.9

 

 

 

1.4

 

Regulatory adjustment

 

 

13.0

 

 

 

5.2

 

 

 

(2.8

)

 

 

11.2

 

 

 

17.0

 

 

 

(1.0

)

 

 

0.8

 

 

 

(9.9

)

 

 

(1.4

)

Total recognized in OCI

 

$

(1.3

)

 

$

(0.6

)

 

$

(0.1

)

 

$

(1.3

)

 

$

(0.6

)

 

$

(0.1

)

 

$

—

 

 

$

—

 

 

$

—

 

 

Spire pension obligations are driven by separate plan and regulatory provisions governing Spire Missouri, Spire Alabama and Spire EnergySouth pension plans.

Pursuant to the provisions of Spire Missouri’s and Spire Alabama’s pension plans, pension obligations may be satisfied by monthly annuities, lump-sum cash payments, or special termination benefits. Lump-sum payments are recognized as settlements (which can result in gains or losses) only if the total of such payments exceeds the sum of service and interest costs in a specific year. Special termination benefits, when offered, are also recognized as settlements which can result in gains or losses.

In the fiscal year ended September 30, 2025 one Spire Missouri plan met the criteria for settlement recognition for lump sum payments, requiring re-measurement of the obligation under that plan using updated census data and assumptions for discount rate and mortality. For the remeasurements, the discount rate for the Missouri plan was updated to 5.55% at September 30, 2025 (from 5.1% at September 30, 2024). Total Spire Missouri lump sum payments recognized as settlements during fiscal 2025 were $1.5.

In the fiscal year ended September 30, 2024 two Spire Missouri plans met the criteria for settlement recognition for lump sum payments, with one of the plans also offering special termination benefits, requiring re-measurement of the obligation under those plans using updated census data and assumptions for discount rate and mortality. For the remeasurements, the discount rate for the Missouri plans were updated to 5.1% at September 30, 2024 (from 6.25% at September 30, 2023). Total Spire Missouri lump sum payments recognized as settlements during fiscal 2024 were $37.3.

Effective December 26, 2021, the pension cost for Spire Missouri’s western territory (Missouri West) included in customer rates was reduced from $5.5 to $4.4 per year. Effective December 26, 2022, the pension cost included in Spire Missouri’s eastern territory (Missouri East) customer rates was decreased from $32.4 to $29.9. The difference between these amounts and pension expense as calculated pursuant to the above and that otherwise would be included in the statements of income and statements of comprehensive income is deferred as a regulatory asset or regulatory liability.

Also effective December 26, 2022, Missouri East prepaid pension assets and other postretirement benefits that were included in rates at $11.0 per year for eight years were reduced to $6.9 per year, with the amortization period being reset for another eight years. Missouri West net liability for pension and other postretirement benefits that were previously reducing rates by $1.1 per year for eight years were reduced to a $0.8 reduction in rates per year, with the amortization period being reset for another eight years.

The following table shows the reconciliation of the beginning and ending balances of the pension benefit obligation at September 30:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Benefit obligation, beginning of year

 

$

469.7

 

 

$

438.7

 

 

$

319.7

 

 

$

313.2

 

 

$

97.9

 

 

$

80.6

 

Service cost

 

 

17.6

 

 

 

15.7

 

 

 

11.4

 

 

 

10.4

 

 

 

5.5

 

 

 

4.6

 

Interest cost

 

 

23.5

 

 

 

26.7

 

 

 

15.8

 

 

 

18.9

 

 

 

5.1

 

 

 

5.1

 

Actuarial loss (gain)

 

 

(15.3

)

 

 

46.0

 

 

 

(8.5

)

 

 

25.2

 

 

 

(4.3

)

 

 

14.3

 

Plan amendments

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

Special termination benefits

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

—

 

Settlement benefits paid

 

 

(1.5

)

 

 

(37.3

)

 

 

(1.5

)

 

 

(37.3

)

 

 

—

 

 

 

—

 

Regular benefits paid

 

 

(43.8

)

 

 

(22.9

)

 

 

(29.7

)

 

 

(13.5

)

 

 

(11.2

)

 

 

(6.7

)

Benefit obligation, end of year

 

$

450.2

 

 

$

469.7

 

 

$

307.2

 

 

$

319.7

 

 

$

93.0

 

 

$

97.9

 

Accumulated benefit obligation, end of year

 

$

439.6

 

 

$

459.4

 

 

$

302.8

 

 

$

314.7

 

 

$

87.3

 

 

$

92.9

 

 

In 2025, all of the qualified plans experienced decreases to their respective benefit obligations. The Spire Qualified Missouri Plans experienced actuarial asset gains while Alabama plan experienced actuarial asset losses. Spire Missouri’s returns exceeded expectations while Alabama’s returns lagged expectations. The discount rates increased between 40 and 45 basis points compared to the prior fiscal year­-end which led to liability gains. Assumed lump sum rates increased since the prior fiscal year end which decreased the liability for each pension plan and contributed to liability gains.

The following table sets forth the reconciliation of the beginning and ending balances of the fair value of plan assets at September 30:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Fair value of plan assets, beginning of year

 

$

374.8

 

 

$

334.7

 

 

$

259.8

 

 

$

242.0

 

 

$

69.9

 

 

$

53.6

 

Actual return on plan assets

 

 

22.4

 

 

 

61.8

 

 

 

19.0

 

 

 

43.2

 

 

 

1.8

 

 

 

10.4

 

Employer contributions

 

 

75.8

 

 

 

38.5

 

 

 

37.2

 

 

 

25.4

 

 

 

30.1

 

 

 

12.6

 

Settlement benefits paid

 

 

(1.5

)

 

 

(37.3

)

 

 

(1.5

)

 

 

(37.3

)

 

 

—

 

 

 

—

 

Regular benefits paid

 

 

(43.8

)

 

 

(22.9

)

 

 

(29.7

)

 

 

(13.5

)

 

 

(11.2

)

 

 

(6.7

)

Fair value of plan assets, end of year

 

$

427.7

 

 

$

374.8

 

 

$

284.8

 

 

$

259.8

 

 

$

90.6

 

 

$

69.9

 

Funded status of plans, end of year

 

$

(22.5

)

 

$

(94.9

)

 

$

(22.4

)

 

$

(59.9

)

 

$

(2.4

)

 

$

(28.0

)

 

The following table sets forth the amounts recognized in the balance sheets at September 30:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Noncurrent assets

 

$

6.2

 

 

$

—

 

 

$

3.9

 

 

$

—

 

 

$

—

 

 

$

—

 

Current liabilities

 

 

(0.6

)

 

 

(1.0

)

 

 

(0.6

)

 

 

(1.0

)

 

 

—

 

 

 

—

 

Noncurrent liabilities

 

 

(28.1

)

 

 

(93.9

)

 

 

(25.7

)

 

 

(58.9

)

 

 

(2.4

)

 

 

(28.0

)

Total

 

$

(22.5

)

 

$

(94.9

)

 

$

(22.4

)

 

$

(59.9

)

 

$

(2.4

)

 

$

(28.0

)

 

Pre-tax amounts recognized in accumulated other comprehensive loss not yet recognized as components of net periodic pension cost consist of:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Net actuarial loss

 

$

100.9

 

 

$

119.7

 

 

$

58.5

 

 

$

72.9

 

 

$

44.5

 

 

$

47.7

 

Prior service credit

 

 

(22.0

)

 

 

(26.4

)

 

 

(12.1

)

 

 

(14.0

)

 

 

(9.1

)

 

 

(11.5

)

Subtotal

 

 

78.9

 

 

 

93.3

 

 

 

46.4

 

 

 

58.9

 

 

 

35.4

 

 

 

36.2

 

Adjustments for amounts included in regulatory
   assets

 

 

(77.8

)

 

 

(90.8

)

 

 

(45.3

)

 

 

(56.4

)

 

 

(35.4

)

 

 

(36.2

)

Total

 

$

1.1

 

 

$

2.5

 

 

$

1.1

 

 

$

2.5

 

 

$

—

 

 

$

—

 

 

The assumptions used to calculate net periodic pension costs for Spire Missouri are as follows:

 

 

2025

 

2024

 

2023

Weighted average discount rate - Spire Missouri East plan

 

5.10%

 

6.25%

 

5.70%

Weighted average discount rate - Spire Missouri West plan

 

5.05%

 

6.30%

 

5.80%

Weighted average rate of future compensation increase

 

3.50%

 

3.00%

 

3.00%

Expected long-term rate of return on plan assets

 

6.50%

 

6.50%

 

6.50%

 

The assumptions used to calculate net periodic pension costs for Spire Alabama are as follows:

 

 

2025

 

2024

 

2023

Weighted average discount rate

 

5.10%

 

6.20%/6.25%

 

5.65%/5.70%

Weighted average rate of future compensation increase

 

3.50%

 

3.00%

 

3.00%

Expected long-term rate of return on plan assets

 

6.75%

 

6.75%

 

6.50%

 

The discount rate is based on long-term, high quality bond indices at the measurement date. The expected long-term rate of return on plan assets is based on historical and projected rates of return for current and planned asset classes in the investment portfolio. Assumed projected rates of return for each asset class were selected after analyzing historical experience and future expectations of the returns. The overall expected rate of return for the portfolio was developed based on the target allocation for each class.

The assumptions used to calculate the benefit obligations are as follows:

 

 

2025

 

2024

Weighted average discount rate - Spire Missouri East plan

 

5.55%

 

5.10%

Weighted average discount rate - Spire Missouri West plan

 

5.45%

 

5.05%

Weighted average discount rate - Spire Alabama plans

 

5.55%

 

5.10%

Weighted average rate of future compensation increase (all plans)

 

3.50%

 

3.50%

Cash balance interest crediting rate - Spire Alabama / Spire Missouri

 

4.25%

 

4.25%

 

The following table sets forth the year-end projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for plans that have a projected benefit obligation and an accumulated benefit obligation in excess of plan assets:

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Projected benefit obligation

 

$

450.2

 

 

$

469.7

 

 

$

307.2

 

 

$

319.7

 

 

$

93.0

 

 

$

97.9

 

Accumulated benefit obligation

 

 

439.6

 

 

 

459.4

 

 

 

302.8

 

 

 

314.7

 

 

 

87.3

 

 

 

92.9

 

Fair value of plan assets

 

 

427.7

 

 

 

374.8

 

 

 

284.8

 

 

 

259.8

 

 

 

90.6

 

 

 

69.9

 

 

The following tables set forth the targeted and actual plan assets by category as of September 30 of each year for Spire Missouri and Spire Alabama:

Spire Missouri

 

2025
Target

 

 

2025
Actual

 

 

2024
Target

 

 

2024
Actual

 

Return seeking assets

 

 

70.0

%

 

 

56.6

%

 

 

70.0

%

 

 

71.3

%

Liability hedging assets

 

 

30.0

%

 

 

40.4

%

 

 

30.0

%

 

 

24.3

%

Cash and cash equivalents

 

 

—

%

 

 

3.0

%

 

 

—

%

 

 

4.4

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

Spire Alabama

 

2025
Target

 

 

2025
Actual

 

 

2024
Target

 

 

2024
Actual

 

Return seeking assets

 

 

75.0

%

 

 

72.0

%

 

 

75.0

%

 

 

74.9

%

Liability hedging assets

 

 

25.0

%

 

 

16.8

%

 

 

25.0

%

 

 

22.6

%

Cash and cash equivalents

 

 

—

%

 

 

11.2

%

 

 

—

%

 

 

2.5

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

The Spire Inc. Retirement Plans Committee is responsible for the administration of the various plans, and all payments under the plans require direction of that committee. The Spire Inc. Defined Benefit Plan Investment Review Committee utilizes an Outsourced Chief Investment Officer (OCIO) model where investment decisions are outsourced to investment consultants (Willis Towers Watson), who in turn become co-fiduciaries with the committee.

For all plans, the Company employs a total return investment approach whereby a mix of equities and fixed income investments are used to maximize the long-term return of plan assets with a prudent level of risk. Risk tolerance is established through consideration of plan liabilities, plan funded status, corporate financial condition and market conditions. The Company has developed an investment strategy that focuses on asset allocation, diversification and quality guidelines. The investment goals are to obtain an adequate level of return to meet future obligations of the plan by providing above average risk-adjusted returns with a risk exposure in the mid-range of comparable funds. Comparative market and peer group benchmarks are utilized to ensure that investment managers are performing satisfactorily. The Company seeks to maintain an appropriate level of diversification to minimize the risk of large losses in a single asset class. Accordingly, plan assets for the pension plans do not have a concentration of assets in a single entity, industry, country, commodity or class of investment fund.

The following table sets forth expected pension benefit payments for the succeeding five fiscal years, and in aggregate for the five fiscal years thereafter, for Spire, Spire Missouri, and Spire Alabama:

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030

 

 

2031 –
2035

 

Spire

 

$

51.2

 

 

$

46.0

 

 

$

45.3

 

 

$

42.9

 

 

$

41.7

 

 

$

196.2

 

Spire Missouri

 

 

38.5

 

 

 

33.4

 

 

 

32.6

 

 

 

30.5

 

 

 

29.1

 

 

 

133.5

 

Spire Alabama

 

 

8.8

 

 

 

8.8

 

 

 

8.5

 

 

 

8.4

 

 

 

8.5

 

 

 

42.8

 

 

The funding policy of Spire Missouri and Spire Alabama is to contribute an amount not less than the minimum required by government funding standards nor more than the maximum deductible amount for federal income tax purposes. Spire

Missouri’s contributions to the pension plans in fiscal 2026 are anticipated to be $22.1 into the qualified trusts, and $0.6 into the non-qualified plans. Spire Alabama’s contributions to the pension plans in fiscal 2026 are anticipated to be $7.0 into the qualified trusts.

Other Postretirement Benefits

Spire and the Utilities provide certain life insurance benefits at retirement. Spire Missouri plans provide for medical insurance after early retirement until age 65. For retirements prior to January 1, 2015, the Missouri West plans provided medical insurance after retirement until death. The Spire Alabama plans provide medical insurance upon retirement until death for certain retirees depending on the type of employee and the date the employee was originally hired.

Net periodic postretirement benefit costs consist of the following components:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Service cost – benefits earned during
   the period

 

$

4.2

 

 

$

4.3

 

 

$

4.8

 

 

$

3.5

 

 

$

3.5

 

 

$

4.0

 

 

$

0.7

 

 

$

0.7

 

 

$

0.7

 

Interest cost on accumulated
   postretirement benefit obligation

 

 

7.3

 

 

 

8.9

 

 

 

8.5

 

 

 

5.2

 

 

 

6.6

 

 

 

6.5

 

 

 

2.0

 

 

 

2.1

 

 

 

1.8

 

Expected return on plan assets

 

 

(16.9

)

 

 

(16.0

)

 

 

(15.8

)

 

 

(11.1

)

 

 

(10.6

)

 

 

(10.5

)

 

 

(5.4

)

 

 

(5.1

)

 

 

(5.0

)

Amortization of prior service cost
   (credit)

 

 

0.2

 

 

 

0.3

 

 

 

0.3

 

 

 

0.3

 

 

 

0.6

 

 

 

0.6

 

 

 

(0.1

)

 

 

(0.3

)

 

 

(0.3

)

Amortization of actuarial gain

 

 

(5.8

)

 

 

(5.8

)

 

 

(4.0

)

 

 

(5.1

)

 

 

(5.2

)

 

 

(3.2

)

 

 

(0.1

)

 

 

(0.1

)

 

 

(0.5

)

Special termination benefits

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Subtotal

 

 

(11.0

)

 

 

(2.2

)

 

 

(6.2

)

 

 

(7.2

)

 

 

1.0

 

 

 

(2.6

)

 

 

(2.9

)

 

 

(2.7

)

 

 

(3.3

)

Regulatory adjustment

 

 

4.5

 

 

 

(3.6

)

 

 

0.6

 

 

 

6.2

 

 

 

(1.9

)

 

 

1.8

 

 

 

(1.8

)

 

 

(1.8

)

 

 

(1.3

)

Net postretirement benefit income

 

$

(6.5

)

 

$

(5.8

)

 

$

(5.6

)

 

$

(1.0

)

 

$

(0.9

)

 

$

(0.8

)

 

$

(4.7

)

 

$

(4.5

)

 

$

(4.6

)

 

Other changes in plan assets and postretirement benefit obligations recognized in OCI include the following:

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Current year actuarial (gain) loss

 

$

(36.5

)

 

$

(52.4

)

 

$

(24.4

)

 

$

(31.9

)

 

$

(40.4

)

 

$

(21.5

)

 

$

(4.0

)

 

$

(9.3

)

 

$

(1.1

)

Amortization of actuarial gain

 

 

5.8

 

 

 

5.8

 

 

 

4.0

 

 

 

5.1

 

 

 

5.2

 

 

 

3.2

 

 

 

0.1

 

 

 

0.1

 

 

 

0.5

 

Current year prior service cost

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Amortization of prior service (cost)
   credit

 

 

(0.2

)

 

 

(0.3

)

 

 

(0.3

)

 

 

(0.3

)

 

 

(0.6

)

 

 

(0.6

)

 

 

0.1

 

 

 

0.3

 

 

 

0.3

 

Subtotal

 

 

(30.9

)

 

 

(51.6

)

 

 

(20.7

)

 

 

(27.1

)

 

 

(40.5

)

 

 

(18.9

)

 

 

(3.8

)

 

 

(8.9

)

 

 

(0.3

)

Regulatory adjustment

 

 

30.9

 

 

 

51.6

 

 

 

20.7

 

 

 

27.1

 

 

 

40.5

 

 

 

18.9

 

 

 

3.8

 

 

 

8.9

 

 

 

0.3

 

Total recognized in OCI

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

Pursuant to a MoPSC Order, the return on plan assets is based on the market-related value of plan assets implemented prospectively over a four-year period. Gains and losses not yet includible in postretirement benefit cost are amortized only to the extent that such gain or loss exceeds 10% of the greater of the accumulated postretirement benefit obligation or the market-related value of plan assets. Such excess is amortized over the average remaining service life of active participants. Effective December 23, 2021, the $8.6 allowance for recovery in rates for Spire Missouri’s postretirement benefit plans was discontinued. The difference between no recovery in rates and postretirement expense as calculated pursuant to the above and that otherwise would be included in the statements of income and statements of comprehensive income is deferred as a regulatory asset or regulatory liability. Effective with the resolution of the 2022 Missouri rate case in December 2022, net liabilities for postretirement benefits reduced rates $0.9 and $0.1 per year for Missouri East and Missouri West, respectively.

In fiscal 2024, Spire Missouri offered an early retirement incentive to select employees, which resulted in a $6.1 increase in the postretirement obligation.

The following table sets forth the reconciliation of the beginning and ending balances of the postretirement benefit obligation at September 30:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Benefit obligation, beginning of year

 

$

142.5

 

 

$

142.6

 

 

$

102.4

 

 

$

105.3

 

 

$

39.0

 

 

$

35.1

 

Service cost

 

 

4.2

 

 

 

4.3

 

 

 

3.5

 

 

 

3.5

 

 

 

0.7

 

 

 

0.7

 

Interest cost

 

 

7.3

 

 

 

8.9

 

 

 

5.2

 

 

 

6.6

 

 

 

2.0

 

 

 

2.1

 

Actuarial (gain) loss

 

 

(18.4

)

 

 

(1.5

)

 

 

(17.1

)

 

 

(3.2

)

 

 

(1.2

)

 

 

3.1

 

Plan amendments

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

—

 

Retiree drug subsidy program

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

Special termination benefits

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

—

 

Benefits paid

 

 

(4.1

)

 

 

(13.4

)

 

 

(1.9

)

 

 

(11.4

)

 

 

(2.2

)

 

 

(2.0

)

Benefit obligation, end of year

 

$

131.5

 

 

$

142.5

 

 

$

92.1

 

 

$

102.4

 

 

$

38.3

 

 

$

39.0

 

 

In fiscal 2025, all the Spire funded plans experienced actuarial asset gains. Each plan’s returns exceeded expectations. The discount rate increased 45 basis points compared to the prior fiscal year-end which led to liability gains.

The following table sets forth the reconciliation of the beginning and ending balances of the fair value of plan assets at September 30:

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Fair value of plan assets at beginning of year

 

$

339.4

 

 

$

286.3

 

 

$

224.9

 

 

$

188.8

 

 

$

107.5

 

 

$

92.0

 

Actual return on plan assets

 

 

34.9

 

 

 

66.3

 

 

 

25.7

 

 

 

47.3

 

 

 

8.2

 

 

 

17.5

 

Employer contributions

 

 

2.7

 

 

 

0.2

 

 

 

2.7

 

 

 

0.2

 

 

 

—

 

 

 

—

 

Benefits paid

 

 

(4.1

)

 

 

(13.4

)

 

 

(1.9

)

 

 

(11.4

)

 

 

(2.2

)

 

 

(2.0

)

Fair value of plan assets, end of year

 

$

372.9

 

 

$

339.4

 

 

$

251.4

 

 

$

224.9

 

 

$

113.5

 

 

$

107.5

 

Funded status of plans, end of year

 

$

241.4

 

 

$

196.9

 

 

$

159.3

 

 

$

122.5

 

 

$

75.2

 

 

$

68.5

 

 

The following table sets forth the amounts recognized in the balance sheets at September 30:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Noncurrent assets

 

$

288.2

 

 

$

248.3

 

 

$

206.1

 

 

$

173.9

 

 

$

75.2

 

 

$

68.5

 

Current liabilities

 

 

(0.4

)

 

 

(0.4

)

 

 

(0.4

)

 

 

(0.4

)

 

 

—

 

 

 

—

 

Noncurrent liabilities

 

 

(46.4

)

 

 

(51.0

)

 

 

(46.4

)

 

 

(51.0

)

 

 

—

 

 

 

—

 

Total

 

$

241.4

 

 

$

196.9

 

 

$

159.3

 

 

$

122.5

 

 

$

75.2

 

 

$

68.5

 

 

Pre-tax amounts recognized in accumulated other comprehensive loss not yet recognized as components of net periodic postretirement benefit cost consist of:

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Net actuarial gain

 

$

(180.6

)

 

$

(150.0

)

 

$

(154.2

)

 

$

(127.5

)

 

$

(19.3

)

 

$

(15.4

)

Prior service cost (credit)

 

 

2.0

 

 

 

2.0

 

 

 

2.0

 

 

 

2.1

 

 

 

—

 

 

 

(0.1

)

Subtotal

 

 

(178.6

)

 

 

(148.0

)

 

 

(152.2

)

 

 

(125.4

)

 

 

(19.3

)

 

 

(15.5

)

Adjustments for amounts included in regulatory
   assets

 

 

178.6

 

 

 

148.0

 

 

 

152.2

 

 

 

125.4

 

 

 

19.3

 

 

 

15.5

 

Total

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

The assumptions used to calculate net periodic postretirement benefit costs for Spire Missouri are as follows:

 

 

2025

 

2024

 

2023

Weighted average discount rate – Spire Missouri plans

 

5.05%

 

6.30%

 

5.80%

Expected long-term rate of return on plan assets – Spire Missouri plans

 

5.50%

 

5.50%

 

5.50%

 

The assumptions used to calculate net periodic postretirement benefit costs for Spire Alabama are as follows:

 

 

2025

 

2024

 

2023

Weighted average discount rate

 

5.05%

 

6.30%

 

5.80%

Expected long-term rate of return on plan assets

 

4.75%/6.00%

 

4.75%/6.00%

 

4.75%/6.00%

 

The discount rate is based on long-term, high quality bond indices at the measurement date. The expected long-term rate of return on plan assets is based on historical and projected rates of return for current and planned asset classes in the investment portfolio. Assumed projected rates of return for each asset class were selected after analyzing historical experience and future expectations of the returns. The overall expected rate of return for the portfolio was developed based on the target allocation for each class.

The weighted average discount rate used to calculate the accumulated postretirement benefit obligations for the Spire Alabama and Spire Missouri plans was 5.50% for 2025 and 5.05% for 2024.

The assumed medical cost trend rates at September 30 are as follows:

 

 

 

2025

 

2024

Medical cost trend assumed for next year – Spire Alabama and Spire Missouri

 

7.00%

 

6.50%

Rate to which the medical cost trend rate is assumed to decline (the ultimate medical
   cost trend rate)

 

5.00%

 

5.00%

Year the rate reaches the ultimate trend

 

2034

 

2031

 

The following tables set forth the targeted and actual plan assets by category as of September 30 of each year for Spire Missouri and Spire Alabama:

Spire Missouri

 

Target

 

 

2025
Actual

 

 

2024
Actual

 

Equity securities

 

 

60.0

%

 

 

58.6

%

 

 

60.8

%

Debt securities

 

 

40.0

%

 

 

36.0

%

 

 

38.2

%

Cash and cash equivalents

 

 

—

%

 

 

5.4

%

 

 

1.0

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

Spire Alabama

 

Target

 

 

2025
Actual

 

 

2024
Actual

 

Equity securities

 

 

60.5

%

 

 

60.9

%

 

 

60.7

%

Debt securities

 

 

39.5

%

 

 

39.1

%

 

 

39.3

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

Missouri and Alabama state laws provide for the recovery in rates of costs accrued pursuant to GAAP provided that such costs are funded through an independent, external funding mechanism. The Utilities have established Voluntary Employees’ Beneficiary Association and Rabbi Trusts as external funding mechanisms. Their investment policies seek to maximize investment returns consistent with their tolerance for risk. Outside investment management specialists are utilized in each asset class. Such specialists are provided with guidelines, where appropriate, designed to ensure that the investment portfolio is managed in accordance with policy. Performance and compliance with the guidelines is regularly monitored. Spire Missouri and Spire Alabama currently invest in mutual funds which are rebalanced periodically to the target allocation. The mutual funds are diversified across U.S. stock and bond markets, and for Spire Alabama, international stock markets.

The following table sets forth expected postretirement benefit payments for the succeeding five fiscal years, and in aggregate for the five fiscal years thereafter for Spire, Spire Missouri, and Spire Alabama:

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030

 

 

2031 –
2035

 

Spire

 

$

13.4

 

 

$

13.0

 

 

$

12.5

 

 

$

12.0

 

 

$

11.6

 

 

$

54.0

 

Spire Missouri

 

 

10.1

 

 

 

9.7

 

 

 

9.3

 

 

 

8.9

 

 

 

8.5

 

 

 

38.3

 

Spire Alabama

 

 

3.2

 

 

 

3.2

 

 

 

3.1

 

 

 

3.0

 

 

 

3.0

 

 

 

15.2

 

 

The Utilities’ funding policy is to contribute amounts to the trusts equal to the periodic benefit cost calculated pursuant to GAAP as recovered in rates. For both Spire Missouri and Spire Alabama there are no anticipated contributions to the postretirement plans in fiscal 2026.

Other Plans

Spire Services Inc. sponsors a 401(k) plan that cover substantially all employees of Spire Inc. and its subsidiaries. The plan allows employees to contribute a portion of their base pay in accordance with specific guidelines. The cost of the defined contribution plan for Spire Inc. totaled $16.5 for fiscal years 2025, and $16.6 for 2024, and $15.5 for 2023, respectively. Spire Missouri provides a match of such contributions within specific limits. The cost of the defined contribution plan for

Spire Missouri amounted to $9.3, $9.3, and $9.1 for fiscal years 2025, 2024, and 2023, respectively. Spire Alabama also provides a match of employee contributions within specific limits. The cost of the defined contribution plan for Spire Alabama amounted to $3.0, $2.9, and $3.1 for fiscal years 2025, 2024, and 2023, respectively.

Fair Value Measurements of Pension and Other Postretirement Plan Assets

For registrants, cash and cash equivalents include money market mutual funds, are valued based on quoted market prices and are recorded as level 1 assets. Debt securities, other than global funds, are valued based on broker/dealer quotations or by using observable market inputs and are recorded as level 1 assets. The US stock/bond mutual funds that are valued at the quoted market price of the identical securities are recorded as level 1 assets. Debt global funds, real asset funds, international funds, and certain US stock/bond mutual funds and equity funds are recorded as level 2 as they have observable inputs other than level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Spire

The table below categorizes the fair value measurements of the Spire pension plan assets:

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

27.4

 

 

$

—

 

 

$

27.4

 

 

$

12.7

 

 

$

—

 

 

$

12.7

 

Equity funds - global (including U.S.)

 

 

—

 

 

 

181.5

 

 

 

181.5

 

 

 

—

 

 

 

152.4

 

 

 

152.4

 

Real asset funds

 

 

—

 

 

 

61.4

 

 

 

61.4

 

 

 

—

 

 

 

57.7

 

 

 

57.7

 

Debt securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. bond funds

 

 

50.7

 

 

 

—

 

 

 

50.7

 

 

 

55.6

 

 

 

—

 

 

 

55.6

 

U.S. government index funds

 

 

38.3

 

 

 

—

 

 

 

38.3

 

 

 

33.9

 

 

 

—

 

 

 

33.9

 

Global funds (including U.S.)

 

 

—

 

 

 

68.4

 

 

 

68.4

 

 

 

—

 

 

 

62.5

 

 

 

62.5

 

Total

 

$

116.4

 

 

$

311.3

 

 

$

427.7

 

 

$

102.2

 

 

$

272.6

 

 

$

374.8

 

 

The table below categorizes the fair value measurements of Spire’s postretirement plan assets:

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

13.1

 

 

$

—

 

 

$

13.1

 

 

$

1.6

 

 

$

—

 

 

$

1.6

 

U.S. stock/bond mutual funds

 

 

294.5

 

 

 

44.4

 

 

 

338.9

 

 

 

229.1

 

 

 

89.0

 

 

 

318.1

 

International fund

 

 

1.4

 

 

 

19.5

 

 

 

20.9

 

 

 

—

 

 

 

19.7

 

 

 

19.7

 

Total

 

$

309.0

 

 

$

63.9

 

 

$

372.9

 

 

$

230.7

 

 

$

108.7

 

 

$

339.4

 

 

Spire Missouri

The table below categorizes the fair value measurements of Spire Missouri’s pension plan assets:

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

10.1

 

 

$

—

 

 

$

10.1

 

 

$

9.9

 

 

$

—

 

 

$

9.9

 

Equity funds - global (including U.S.)

 

 

—

 

 

 

117.1

 

 

 

117.1

 

 

 

—

 

 

 

102.2

 

 

 

102.2

 

Real asset funds

 

 

—

 

 

 

43.1

 

 

 

43.1

 

 

 

—

 

 

 

40.2

 

 

 

40.2

 

Debt securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. bond funds

 

 

35.1

 

 

 

—

 

 

 

35.1

 

 

 

38.2

 

 

 

—

 

 

 

38.2

 

U.S. government index funds

 

 

30.2

 

 

 

—

 

 

 

30.2

 

 

 

25.2

 

 

 

—

 

 

 

25.2

 

Global funds (including U.S.)

 

 

—

 

 

 

49.2

 

 

 

49.2

 

 

 

—

 

 

 

44.1

 

 

 

44.1

 

Total

 

$

75.4

 

 

$

209.4

 

 

$

284.8

 

 

$

73.3

 

 

$

186.5

 

 

$

259.8

 

 

The table below categorizes the fair value measurements of Spire Missouri’s postretirement plan assets:

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

12.1

 

 

$

—

 

 

$

12.1

 

 

$

0.7

 

 

$

—

 

 

$

0.7

 

U.S. stock/bond mutual funds

 

 

239.3

 

 

 

—

 

 

 

239.3

 

 

 

224.2

 

 

 

—

 

 

$

224.2

 

Total

 

$

251.4

 

 

$

—

 

 

$

251.4

 

 

$

224.9

 

 

$

—

 

 

$

224.9

 

 

Spire Alabama

The table below categorizes the fair value measurements of Spire Alabama’s pension plan assets:

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

10.2

 

 

$

—

 

 

$

10.2

 

 

$

1.7

 

 

$

—

 

 

$

1.7

 

Equity funds - global (including U.S.)

 

 

—

 

 

 

41.3

 

 

 

41.3

 

 

 

—

 

 

 

30.6

 

 

 

30.6

 

Real asset funds

 

 

—

 

 

 

11.7

 

 

 

11.7

 

 

 

—

 

 

 

10.6

 

 

 

10.6

 

Debt securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. bond funds

 

 

9.9

 

 

 

—

 

 

 

9.9

 

 

 

10.6

 

 

 

—

 

 

 

10.6

 

U.S. government index funds

 

 

5.2

 

 

 

—

 

 

 

5.2

 

 

 

5.2

 

 

 

—

 

 

 

5.2

 

Global funds (including U.S.)

 

 

—

 

 

 

12.3

 

 

 

12.3

 

 

 

—

 

 

 

11.2

 

 

 

11.2

 

Total

 

$

25.3

 

 

$

65.3

 

 

$

90.6

 

 

$

17.5

 

 

$

52.4

 

 

$

69.9

 

 

The table below categorizes the fair value measurements of Spire Alabama’s postretirement plan assets:

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

U.S. stock/bond mutual funds

 

$

49.6

 

 

$

44.4

 

 

$

94.0

 

 

$

—

 

 

$

89.0

 

 

$

89.0

 

International fund

 

 

—

 

 

 

19.5

 

 

 

19.5

 

 

 

—

 

 

 

18.5

 

 

 

18.5

 

Total

 

$

49.6

 

 

$

63.9

 

 

$

113.5

 

 

$

—

 

 

$

107.5

 

 

$

107.5

 
v3.25.3
Segment Information
 12 Months Ended
Sep. 30, 2025
Segment Reporting [Abstract]  
Segment Information

14. SEGMENT INFORMATION

The Company has three reportable segments: Gas Utility, Gas Marketing, and Midstream. The Gas Utility segment is the aggregation of the operations of the Utilities. The Gas Utility segment consists of our natural gas utilities: Spire Missouri Inc. (“Spire Missouri”) (serving areas of Missouri, including the St. Louis and Kansas City regions), Spire Alabama Inc. (serving central and northern Alabama, including Birmingham and Montgomery), Spire Gulf Inc. (serving southwestern Alabama, including Mobile) and Spire Mississippi Inc. (serving south-central Mississippi, including Hattiesburg). The Gas Marketing segment includes the results of Spire Marketing, a subsidiary engaged in the non-regulated marketing of natural gas and related activities, including utilizing natural gas storage contracts for providing natural gas sales. The Midstream segment includes Spire Storage, Spire STL Pipeline and Spire MoGas Pipeline, which are subsidiaries engaged in the storage and transportation of natural gas. All other components of the Company’s consolidated information include Spire’s subsidiaries engaged in the operation of a propane pipeline and risk management, among other activities, and unallocated corporate items, including certain debt and associated interest costs.

Spire

 

Spire’s chief operating decision maker ("CODM") is the chief executive officer. The CODM and management evaluate the performance of the segments based on the computation of adjusted earnings. Adjusted earnings excludes from reported net income, as applicable, the after-tax impacts of fair value accounting and timing adjustments associated with energy-related transactions, the impacts of acquisition, divestiture and restructuring activities, and the largely non-cash impacts of other non-recurring or unusual items such as certain regulatory, legislative or GAAP standard-setting actions. For each of the Company’s segments, the CODM uses adjusted earnings to allocate resources and determine reinvestment for each segment, predominantly in the annual budget and forecasting process. Adjusted earnings is also used to monitor budget versus actual results to assess performance of the segment and establish management compensation. The CODM does not receive asset information for the individual reportable segments.

Spire Missouri

As a separate public gas utility company operating in a single state, Spire Missouri is a single reportable segment. The chief executive officer is the CODM, who assesses performance and decides how to allocate resources based on net income. The CODM uses comparisons of actual results with budgeted and prior year results to assess performance of Spire Missouri and in establishing management’s compensation. The CODM does not receive asset information other than asset information reported on the Spire Missouri Balance Sheets. Financial data related to income and expenses, including gross receipt taxes which are disclosed separately, for the single reportable segment are reported on Spire Missouri’s Statements of Comprehensive Income.

 

Financial data related to gross receipt taxes and capital expenditures are as follows:

 

 

 

2025

 

 

2024

 

 

2023

 

Gross Receipt Taxes

 

$

82.9

 

 

$

93.1

 

 

$

96.7

 

Capital Expenditures

 

 

641.2

 

 

 

553.0

 

 

 

447.5

 

 

Spire Alabama

 

As a separate public gas utility company operating in a single state, Spire Alabama is a single reportable segment. The chief executive officer is the CODM, who assesses performance and decides how to allocate resources based on net income. The CODM uses comparisons of actual results with budgeted and prior year results to assess performance of each company and in establishing management’s compensation. The CODM does not receive asset information other than asset information reported on the Spire Alabama Balance Sheets. Financial data related to income and expenses, including gross receipts taxes which are disclosed separately, for the single reportable segment are reported on Spire Alabama’s Statements of Income.

Financial data related to gross receipt taxes and capital expenditures are as follows:

 

 

2025

 

 

2024

 

 

2023

 

Gross Receipt Taxes

 

 

27.9

 

 

 

30.1

 

 

 

29.9

 

Capital Expenditures

 

 

144.2

 

 

 

112.8

 

 

 

117.6

 

 

 

Spire

The accounting policies of the segments are the same as those described in Note 1, Summary of Significant Accounting Policies. Spire’s intersegment transactions include sales of natural gas from Spire Marketing to Spire Missouri, Spire Alabama and Spire Storage; sales of natural gas from Spire Missouri to Spire Marketing; storage services from Spire Storage to Spire Missouri and Spire Marketing; and natural gas transportation services provided by Spire STL Pipeline and Spire MoGas Pipeline to Spire Missouri and Spire Marketing. The basis of accounting for intersegment transactions is the same as that for third party transactions. For more information about segment revenue, see Note 2, Revenue.

The following tables present information about Spire’s segment revenue, segment expenses, and Adjusted Earnings.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2025

 

Gas Utility

 

 

Gas Marketing

 

 

Midstream

 

 

Total Reportable Segments

 

 

Other(b)

 

 

Intersegment Eliminations

 

 

Consolidated

 

Revenues from external customers

 

$

2,207.5

 

 

$

157.2

 

 

$

109.2

 

 

$

2,473.9

 

 

$

2.5

 

 

$

—

 

 

$

2,476.4

 

Intersegment revenues

 

 

0.1

 

 

 

-

 

 

 

46.3

 

 

 

46.4

 

 

 

—

 

 

 

(46.4

)

 

 

-

 

Total Operating Revenues

 

 

2,207.6

 

 

 

157.2

 

 

 

155.5

 

 

 

2,520.3

 

 

 

2.5

 

 

 

(46.4

)

 

 

2,476.4

 

Less:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Significant segment expenses:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Cost of gas sold, incl. gross receipts taxes

 

 

970.9

 

 

 

93.7

 

 

 

3.0

 

 

 

1,067.6

 

 

 

—

 

 

 

(46.4

)

 

 

1,021.2

 

  Operation and maintenance expense

 

 

467.1

 

 

 

19.4

 

 

 

45.3

 

 

 

531.8

 

 

 

10.3

 

 

 

—

 

 

 

542.1

 

Depreciation and amortization
   expense

 

 

277.6

 

 

 

1.0

 

 

 

19.2

 

 

 

297.8

 

 

 

0.4

 

 

 

—

 

 

 

298.2

 

Interest expense

 

 

137.1

 

 

 

—

 

 

 

11.6

 

 

 

148.7

 

 

 

55.4

 

 

 

—

 

 

 

204.1

 

Income tax expense (benefit)

 

 

47.4

 

 

 

11.1

 

 

 

15.7

 

 

 

74.2

 

 

 

(14.5

)

 

 

—

 

 

 

59.7

 

Other segment items (a)

 

 

76.1

 

 

 

6.1

 

 

 

4.4

 

 

 

86.6

 

 

 

(11.0

)

 

 

—

 

 

 

75.6

 

Adjusted earnings (loss) [Non-GAAP]

 

$

231.4

 

 

$

25.9

 

 

$

56.3

 

 

$

313.6

 

 

$

(38.1

)

 

$

-

 

 

$

275.5

 

Capital expenditures

 

 

816.8

 

 

 

0.1

 

 

 

106.8

 

 

 

923.7

 

 

 

(1.3

)

 

 

—

 

 

 

922.4

 

 

2024

 

Gas Utility

 

 

Gas Marketing

 

 

Midstream

 

 

Total Reportable Segments

 

 

Other(b)

 

 

Intersegment Eliminations

 

 

Consolidated

 

Revenues from external customers

 

$

2,436.2

 

 

$

99.2

 

 

$

56.9

 

 

$

2,592.3

 

 

$

0.7

 

 

$

—

 

 

$

2,593.0

 

Intersegment revenues

 

 

1.7

 

 

 

—

 

 

 

43.8

 

 

 

45.5

 

 

 

-

 

 

 

(45.5

)

 

 

-

 

Total Operating Revenues

 

 

2,437.9

 

 

 

99.2

 

 

 

100.7

 

 

 

2,637.8

 

 

 

0.7

 

 

 

(45.5

)

 

 

2,593.0

 

Less:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Significant segment expenses:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Cost of gas sold, incl. gross receipts taxes

 

 

1,238.7

 

 

 

37.1

 

 

 

1.1

 

 

 

1,276.9

 

 

 

0.1

 

 

 

(45.5

)

 

 

1,231.5

 

  Operation and maintenance expense

 

 

452.8

 

 

 

18.2

 

 

 

34.7

 

 

 

505.7

 

 

 

1.7

 

 

 

—

 

 

 

507.4

 

Depreciation and amortization
   expense

 

 

263.6

 

 

 

1.5

 

 

 

12.8

 

 

 

277.9

 

 

 

0.5

 

 

 

—

 

 

 

278.4

 

Interest expense

 

 

147.3

 

 

 

—

 

 

 

7.0

 

 

 

154.3

 

 

 

46.8

 

 

 

—

 

 

 

201.1

 

Income tax expense (benefit)

 

 

48.0

 

 

 

10.8

 

 

 

9.6

 

 

 

68.4

 

 

 

(9.7

)

 

 

—

 

 

 

58.7

 

Other segment items (a)

 

 

66.7

 

 

 

8.2

 

 

 

2.0

 

 

 

76.9

 

 

 

(8.4

)

 

 

—

 

 

 

68.5

 

Adjusted earnings (loss) [Non-GAAP]

 

$

220.8

 

 

$

23.4

 

 

$

33.5

 

 

$

277.7

 

 

$

(30.3

)

 

$

-

 

 

$

247.4

 

Capital expenditures

 

 

691.1

 

 

 

0.1

 

 

 

171.3

 

 

 

862.5

 

 

 

(1.2

)

 

 

—

 

 

 

861.3

 

 

2023

 

Gas Utility

 

 

Gas Marketing

 

 

Midstream

 

 

Total Reportable Segments

 

 

Other(b)

 

 

Intersegment Eliminations

 

 

Consolidated

 

Revenues from external customers

 

$

2,456.6

 

 

$

179.1

 

 

$

29.9

 

 

$

2,665.6

 

 

$

0.7

 

 

$

—

 

 

$

2,666.3

 

Intersegment revenues

 

 

0.3

 

 

 

—

 

 

 

36.2

 

 

 

36.5

 

 

 

—

 

 

 

(36.5

)

 

 

-

 

Total Operating Revenues

 

 

2,456.9

 

 

 

179.1

 

 

 

66.1

 

 

 

2,702.1

 

 

 

0.7

 

 

 

(36.5

)

 

 

2,666.3

 

Less:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Significant segment expenses:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Cost of gas sold, incl. gross receipts taxes

 

 

1,321.1

 

 

 

108.0

 

 

 

—

 

 

 

1,429.1

 

 

 

—

 

 

 

(36.5

)

 

 

1,392.6

 

  Operation and maintenance expense

 

 

461.8

 

 

 

19.4

 

 

 

30.5

 

 

 

511.7

 

 

 

5.9

 

 

 

—

 

 

 

517.6

 

Depreciation and amortization
   expense

 

 

244.4

 

 

 

1.5

 

 

 

8.4

 

 

 

254.3

 

 

 

0.5

 

 

 

—

 

 

 

254.8

 

Interest expense

 

 

139.9

 

 

 

—

 

 

 

8.6

 

 

 

148.5

 

 

 

37.2

 

 

 

—

 

 

 

185.7

 

Income tax expense (benefit)

 

 

32.7

 

 

 

12.8

 

 

 

3.8

 

 

 

49.3

 

 

 

(10.5

)

 

 

—

 

 

 

38.8

 

Other segment items (a)

 

 

56.5

 

 

 

(10.2

)

 

 

0.7

 

 

 

47.0

 

 

 

1.7

 

 

 

—

 

 

 

48.7

 

Adjusted earnings (loss)

 

$

200.5

 

 

$

47.6

 

 

$

14.1

 

 

$

262.2

 

 

$

(34.1

)

 

—

 

 

$

228.1

 

Capital expenditures

 

 

588.6

 

 

 

0.4

 

 

 

73.6

 

 

 

662.6

 

 

 

(0.1

)

 

 

—

 

 

 

662.5

 

 

(a) Other segment items for each reportable segment include fair value and timing adjustments, acquisition and restructuring activities, taxes other than income and gross receipt taxes, and miscellaneous income and deductions.

 

(b) All other components of the Company's consolidated information include Spire's subsidiaries engaged in the operation of a propane pipeline and risk management, among other activities, and unallocated corporate items, including certain debt and associated interest costs.

 

 

Reconciliation of Consolidated Net Income to Consolidated Adjusted Earnings

 

2025

 

 

2024

 

 

2023

 

Net Income

 

$

271.7

 

 

$

250.9

 

 

$

217.5

 

Adjustments, pre-tax:

 

 

 

 

 

 

 

 

 

Fair value and timing adjustments

 

 

(10.4

)

 

 

(12.4

)

 

 

11.4

 

Acquisition and restructuring activities

 

 

15.2

 

 

 

7.6

 

 

 

2.5

 

Income tax adjustments

 

 

(1.0

)

 

 

1.3

 

 

 

(3.3

)

Adjusted Earnings

 

$

275.5

 

 

$

247.4

 

 

$

228.1

 
v3.25.3
Regulatory Matters
 12 Months Ended
Sep. 30, 2025
Regulated Operations [Abstract]  
Regulatory Matters

15. REGULATORY MATTERS

As discussed below for Spire Missouri and Spire Alabama, the PGA clauses and GSA riders allow the Utilities to pass through to customers the cost of purchased gas supplies. Regulatory assets and regulatory liabilities related to the PGA clauses and the GSA rider are both labeled Unamortized Purchased Gas Adjustments herein.

The following regulatory assets and regulatory liabilities were reflected in the balance sheets of the Company, Spire Missouri and Spire Alabama as of September 30, 2025 and 2024.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

September 30

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Regulatory Assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unamortized purchased gas adjustments

 

$

16.5

 

 

$

28.9

 

 

$

14.9

 

 

$

28.1

 

 

$

—

 

 

$

—

 

Other

 

 

61.8

 

 

 

86.5

 

 

 

34.0

 

 

 

55.9

 

 

 

16.1

 

 

 

19.2

 

Total Current Regulatory Assets

 

 

78.3

 

 

 

115.4

 

 

 

48.9

 

 

 

84.0

 

 

 

16.1

 

 

 

19.2

 

Noncurrent:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Future income taxes due from customers

 

 

154.2

 

 

 

150.7

 

 

 

146.6

 

 

 

142.7

 

 

 

1.6

 

 

 

1.8

 

Pension and postretirement benefit costs

 

 

217.8

 

 

 

237.5

 

 

 

157.0

 

 

 

166.5

 

 

 

59.1

 

 

 

68.2

 

Cost of removal

 

 

688.3

 

 

 

668.2

 

 

 

98.8

 

 

 

97.0

 

 

 

589.6

 

 

 

571.2

 

Unamortized purchased gas adjustments

 

 

9.0

 

 

 

1.2

 

 

 

9.0

 

 

 

1.2

 

 

 

—

 

 

 

—

 

Energy efficiency

 

 

65.0

 

 

 

61.0

 

 

 

65.0

 

 

 

61.0

 

 

 

—

 

 

 

—

 

Other

 

 

189.2

 

 

 

133.2

 

 

 

176.8

 

 

 

119.6

 

 

 

0.3

 

 

 

0.8

 

Total Noncurrent Regulatory Assets

 

 

1,323.5

 

 

 

1,251.8

 

 

 

653.2

 

 

 

588.0

 

 

 

650.6

 

 

 

642.0

 

Total Regulatory Assets

 

$

1,401.8

 

 

$

1,367.2

 

 

$

702.1

 

 

$

672.0

 

 

$

666.7

 

 

$

661.2

 

Regulatory Liabilities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unamortized purchased gas adjustments

 

$

34.9

 

 

$

42.3

 

 

$

13.9

 

 

$

10.2

 

 

$

20.2

 

 

$

30.9

 

Other

 

 

4.5

 

 

 

7.2

 

 

 

—

 

 

 

—

 

 

 

0.1

 

 

 

2.9

 

Total Current Regulatory Liabilities

 

 

39.4

 

 

 

49.5

 

 

 

13.9

 

 

 

10.2

 

 

 

20.3

 

 

 

33.8

 

Noncurrent:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Deferred taxes due to customers

 

 

100.3

 

 

 

114.2

 

 

 

88.8

 

 

 

101.8

 

 

 

—

 

 

 

—

 

Pension and postretirement benefit costs

 

 

300.1

 

 

 

232.9

 

 

 

261.2

 

 

 

196.6

 

 

 

26.5

 

 

 

25.1

 

Accrued cost of removal

 

 

138.2

 

 

 

133.6

 

 

 

96.0

 

 

 

94.5

 

 

 

—

 

 

 

—

 

Unamortized purchased gas adjustments

 

 

6.5

 

 

 

17.2

 

 

 

6.5

 

 

 

17.2

 

 

 

—

 

 

 

—

 

Other

 

 

32.9

 

 

 

37.6

 

 

 

28.8

 

 

 

33.2

 

 

 

2.7

 

 

 

3.2

 

Total Noncurrent Regulatory Liabilities

 

 

578.0

 

 

 

535.5

 

 

 

481.3

 

 

 

443.3

 

 

 

29.2

 

 

 

28.3

 

Total Regulatory Liabilities

 

$

617.4

 

 

$

585.0

 

 

$

495.2

 

 

$

453.5

 

 

$

49.5

 

 

$

62.1

 

 

A portion of the Company’s and Spire Missouri's regulatory assets are not earning a return, as shown in the table below:

 

 

 

Spire

 

 

Spire Missouri

 

September 30

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Pension and postretirement benefit costs

 

$

119.1

 

 

$

129.7

 

 

$

119.1

 

 

$

129.7

 

Future income taxes due from customers

 

 

152.7

 

 

 

148.9

 

 

 

146.6

 

 

 

142.7

 

Unamortized purchase gas adjustments

 

 

23.9

 

 

 

29.3

 

 

 

23.9

 

 

 

29.3

 

Other

 

 

177.0

 

 

 

132.5

 

 

 

177.0

 

 

 

132.5

 

Total Regulatory Assets Not Earning a Return

 

$

472.7

 

 

$

440.4

 

 

$

466.6

 

 

$

434.2

 

 

Like all the Company’s regulatory assets, these regulatory assets as of September 30, 2025 are expected to be recovered from customers in future rates. The recovery period for the future income taxes due from customers and pension and other postretirement benefit costs could be 20 years or longer, based on current Internal Revenue Service guidelines and average remaining service life of active participants, respectively. The recovery period for the PGA assets is about one year. The other items not earning a return are expected to be recovered over a period not to exceed 15 years, consistent with precedent set by the MoPSC, except for certain debt costs expected to be recovered over the related debt term (currently to 2057) and the diaphragm meter recovery over 20 years. Spire Alabama does not have any regulatory assets that are not earning a return.

Spire Missouri

As authorized by the MoPSC, the PGA clause allows Spire Missouri to flow through to customers, subject to prudence review by the MoPSC, the cost of purchased gas supplies. To better match customer billings with market natural gas prices, Spire Missouri is allowed to file to modify, on a periodic basis, the level of gas costs in its PGA. Some provisions of the PGA clause are:

•
Spire Missouri has a risk management policy that allows for the purchase of natural gas derivative instruments with the goal of managing price risk associated with purchasing natural gas on behalf of its customers. The MoPSC clarified that costs, cost reductions, and carrying costs associated with the Utility’s use of natural gas derivative instruments are gas costs recoverable through the PGA mechanism.
•
The tariffs allow Spire Missouri flexibility to make up to three discretionary PGA changes during each year, in addition to its mandatory November PGA change, so long as such changes are separated by at least two months.
•
Spire Missouri is authorized to apply carrying costs to all over- or under-recoveries of gas costs, including cost increases and cost reductions associated with the use of derivative instruments, including cash payments for margin deposits.
•
Pre-tax income from off-system sales and capacity release revenues is shared with customers such that customers receive 75% and Spire Missouri receives 25% (after the first $2.2 of annual value from capacity release goes entirely to customers through fiscal 2029 for Spire Missouri West).

Pursuant to the provisions of the PGA clause, the difference between actual costs incurred and costs recovered through the application of the PGA clause, as well as the actual amount of off-system sales and capacity release revenues allocated to customers, are reflected as a regulatory asset or liability at the end of the fiscal year. At that time, the balance is classified as a current asset or current liability and recovered from, or credited to, customers over an annual period commencing in the subsequent November. The balance in the current account is amortized as amounts are reflected in customer billings. On November 12, 2024, based on a recent Spire Missouri filing, the MoPSC approved a PGA decrease of approximately 30% for both service territories effective November 15, 2024. On November 12, 2025, Spire Missouri filed a PGA adjustment increase for both Missouri service territories, with rates proposed to become effective November 26, 2025, pending MoPSC approval.

In fiscal 2025, Spire Missouri filed a general rate case (Case No. GR-2025-0107) requesting a base rate increase. On September 3, 2025, the MoPSC approved a stipulation and agreement in Spire Missouri’s general rate case. The approved agreement provides for a base rate increase of $210.0, which became effective on October 24, 2025. The approved base rate incorporates the $72.6 from customers through ISRS for eligible capital projects through February 2025, resulting in a net base rate increase of $137.4. The terms of the agreement do not impact any amounts previously recorded. The approved rates are based on a total rate base plant in service of $4,379.6, reflecting significant infrastructure investments since Spire’s last general rate filing, and include a 7.05% post-tax total rate of return for future ISRS purposes.

The Infrastructure System Replacement Surcharge (ISRS) allows Spire Missouri expedited recovery for its investment to replace qualifying components of its infrastructure without the necessity of a formal rate case. On January 17, 2025, Spire Missouri filed an ISRS case for eligible capital projects from September 2024 through February 2025 (including estimates for January and February). On April 17, the MoPSC Staff recommended an increase of $19.0, to which no party objected. The MoPSC authorized new rates effective May 14, 2025, resulting in total annual ISRS revenues of $72.6. All ISRS charges reset to zero on October 24, 2025 when new base rates took effect under the general rate case described above.

Spire Alabama

In September 2022, the APSC approved the renewal of the RSE through September 30, 2025, with certain modifications to the previous terms. Under RSE, the APSC conducts reviews in March, June and September to determine whether Spire Alabama’s return on average common equity (RCE) at the end of the rate year will be within the allowed range of return. Reductions in rates can be made quarterly to bring the projected RCE within the allowed range; increases, however, are allowed only once each rate year, effective December 1, and cannot exceed 4% of prior-year revenues. Effective October 1, 2022, Spire Alabama's allowed range of RCE is 9.50% to 9.90% with an adjusting point of 9.70%. Previously, the allowed range was 10.15% to 10.65% with an adjusting point of 10.40%. Spire Alabama is subject to a performance-based adjustment of plus or minus 10 basis points to the RCE adjusting point, based upon the terms of the previously approved Accelerated Infrastructure Modernization (AIM) Program tariff; however, Spire applied for and received approval to suspend the operation of the AIM performance-based adjustment for 2022, 2023, 2024 and 2025, impacting fiscal years 2023 through 2026. Spire Alabama’s equity as a percent of total capitalization is limited to 55.5%, and Average Common Equity growth is limited to 6.00% each year. In October 2025, Spire Alabama submitted its annual RSE filing to the APSC, indicating that the RSE framework will continue beyond September 30, 2025. The filing projects a return on average common equity of 8.24% for the upcoming rate year, which falls below the approved range, resulting in rate adjustments scheduled to take effect on December 1, 2025, in line with RSE guidelines.

In the first quarter of fiscal 2023, Spire Alabama made its annual RSE rate filing with the APSC, presenting the utility’s budget for the fiscal year ended September 30, 2024, and new rates designed to provide an annual revenue increase of $15.0 became effective January 1, 2023. On October 26, 2023, Spire Alabama made its annual RSE rate filing, presenting the utility’s budget for the fiscal year ending September 30, 2025. After an amended filing on December 27, 2023, new rates designed to provide an annual revenue increase of $14.3 became effective January 1, 2024. At the September 30, 2024 point of test, the RCE was above the allowed range, resulting in a reduction in rates totaling $4.0 annually effective in December 2024. On October 24, 2024, Spire Alabama made its annual RSE rate filing (based on its budget for fiscal 2025) including proposed rates designed to provide an annual revenue increase of $3.6, subject to review by the APSC staff and the Office of the Attorney General. The final budget was filed and approved on November 26, 2024. The filing included an increase to the Company’s return on equity that was offset by cost reductions due to customer affordability efforts, and therefore no adjustment was required to base rates that went into effect on December 1, 2024. On October 24, 2025, Spire Alabama made its annual RSE rate filing (based on its budget for fiscal 2026) including proposed rates designed to provide an annual revenue increase of $15.6, subject to review by the APSC staff and the Office of the Attorney General.

The inflation-based Cost Control Measure (CCM) established by the APSC allows for annual changes in operation and maintenance (“O&M”) expense relative to an index range. Effective October 1, 2022, the Base Year O&M expense was computed by averaging the actual O&M expenses for 2020, 2021, and 2022. The Base CPI-U was computed by averaging the August CPI-U for 2020, 2021, 2022. The “Index” is computed by measuring the change from the Base CPI-U to the August CPI-U of the most recently completed fiscal year, less a factor of 1.50%. The index range will be computed by adjusting the Index plus or minus 1.50%. If rate year O&M expense falls within the index range, no adjustment is required. If rate year O&M expense exceeds the index range, three-quarters of the difference is returned to customers through future rate adjustments. To the extent rate year O&M is less than the index range, Spire Alabama benefits by one-half of the difference through future rate adjustments. If a benefit is achieved, the Base Year and the Base CPI-U for the following year will each be reset to an average of the three preceding completed years. If a benefit is not achieved, the Base Year and Base CPI-U will not be updated. Certain items that fluctuate based on situations demonstrated to be beyond Spire Alabama’s control may be excluded from the CCM calculation. Spire Alabama recorded a CCM benefit for rate year 2022 of $17.2. To mitigate the impact on ratepayers, Spire requested and received approval to recover the rate year 2022 CCM benefit over five years (with recognition of revenue only up to 24 months in advance of recovery), of which approximately $10.0 has been collected to date as September 30, 2025. Spire Alabama recorded CCM benefits for rate years 2023 and 2024 of $4.4 and $2.5, respectively, which have been fully recovered as of September 30, 2025. For the rate year ending September 30, 2025, Spire Alabama’s O&M expenses fell within the allowed index range under the CCM provision, and as a result, no adjustment to rates (or related CCM benefit or refund) was proposed—subject to review and approval by the Alabama Public Service Commission.

Spire Alabama’s rate schedules for natural gas distribution charges contain a GSA rider which permits the pass-through to customers of changes in the cost of gas supply. Spire Alabama’s tariff provides a temperature adjustment mechanism, also included in the GSA rider, which is designed to moderate the impact of departures from normal temperatures on Spire Alabama’s earnings. The temperature adjustment applies primarily to residential, small commercial and small industrial customers. Other non-temperature weather-related conditions that may affect customer usage are not included in the temperature adjustment. There is also a mechanism under Spire Alabama's GSA rider allowing the utility to create value through off-system sales of excess natural gas supply and capacity and to give 75% of the value created to customers while retaining 25% (after the first $1.6 of value from capacity release goes entirely to customers). In fiscal 2023, GSA rate increases were effective December 1, 2022 and January 1, 2023, and in fiscal 2024, GSA rate decreases were effective October 1, 2023, January 1, 2024, April 1, 2024, and October 1, 2024, primarily attributable to changes in natural gas commodity prices.

Spire

In addition to those discussed above for Spire Missouri and Spire Alabama, Spire is affected by the following regulatory matters.

Spire Gulf has similar rate regulation to Spire Alabama. Its RSE rate-setting mechanism was renewed in September 2021 for a four-year term through September 2025. The RSE allowed RCE range is 9.70% to 10.30% with an adjusting point of 9.95% for fiscal 2022 through fiscal 2025. Spire Gulf filed its RSE point of test as of April 30, 2023 with the APSC reflecting that its projected RCE exceeded the allowed RCE resulting in an annualized refund of $1.8 that became effective July 1, 2023. Spire Gulf’s September 30, 2024 RSE point of test reflected that its actual RCE still exceeded the allowed RCE, resulting in an additional annualized refund of $2.0 that became effective December 13, 2023. In the first quarter of fiscal 2024, Spire Gulf made its annual RSE filing (based on its budget for fiscal 2024) reflecting a further increase in annual revenues of $2.7 which also became effective December 13, 2023. On October 25, 2024, Spire Gulf made its annual RSE filing (based on its budget for fiscal 2025) reflecting a further increase in annual revenues of $1.9, pending regulatory review. The final budget was filed and approved on December 2, 2024, reflecting an approved increase in annual revenues of $1.3, with new rates effective December 4, 2024. On October 23, 2025, Spire Gulf made its annual RSE filing (based on its budget for fiscal 2026) reflecting a further increase in annual revenues of $3.5, pending regulatory review. Spire Gulf’s CCM has evaluation and recovery provisions when expenses exceed or are under a band of plus or minus 1.50% around the CPI-U inflated O&M per customer expense level from the base year, excluding expenses for pensions and gas bad debt. The base year for the O&M index was 2021 for fiscal 2022. Since a CCM benefit was recorded in fiscal 2022, the base year O&M index for fiscal 2023 through fiscal 2025 will be the 2022 O&M level. Spire Gulf’s O&M for fiscal 2024 was within the O&M per customer inflation adjusted band. Spire Gulf’s O&M for fiscal 2025 reflected a benefit of $0.2. Spire Gulf has a Cast Iron Main Replacement Factor (CIF) that provides an enhanced return on the pro-rata costs associated with cast iron main replacement exceeding 10 miles per year based on a 75% weighting for the equity content. Capital expenditures recovered under the CIF have not increased since fiscal 2019 pursuant to applicable tariff provisions although the Company is continuing to recover costs of service associated with accumulated expenditures under the CIF. Spire Gulf also has an ESR for negative revenue variances over $0.1 or a force majeure event expense of $0.1 (or two events that exceed $0.15) and an Environmental Cost Recovery Factor that recovers 90% of prudently incurred costs for compliance with environmental laws, rules and regulations. Spire Gulf has an APSC-approved intercompany revolving credit agreement with Spire to borrow in a principal amount not to exceed $75.0 and to loan up to $25.0.

Spire Mississippi utilizes a formula rate-making process under the RSA. An allowed return on equity (currently 10.73%) is computed annually and compared to the actual return on equity based on a rate year ending June 30. If the actual equity return on an end of period rate base is beyond the allowed return on equity by 1.0%, then 75% of any shortfall is recovered through a rate increase and 50% of any excess results in a rate decrease. Updates may include known and measurable adjustments to historic costs from the 12 months ended June 30, submitted September 15 for an effective date of November 1, unless disputed by the Mississippi Public Utilities Staff (MPUS), with any disputes to be resolved by the Mississippi Public Service Commission (MSPSC) by January 15 of the following year. The MSPSC approved stipulation agreements between the MPUS and Spire Mississippi that provided for increased annual revenues of $0.8, $1.0, and $0.6 through rates effective on January 1, 2023, January 1, 2024, and January 1, 2025, respectively. Spire Mississippi’s RSA filing made on September 12, 2025 reflected a further rate increase of approximately $0.8 and is pending review by the MPUS. Additionally, a Supplemental Growth Rider provides recovery of certain Spire Mississippi system expansion projects to serve qualified economic development projects.
v3.25.3
Commitments and Contingencies
 12 Months Ended
Sep. 30, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies

16. COMMITMENTS AND CONTINGENCIES

Commitments

The Company and the Utilities have entered into contracts with various counterparties, expiring on dates through calendar 2039, for the storage, transportation, and supply of natural gas. Minimum payments required under the contracts in place at September 30, 2025, are estimated at $1,762.8, $1,388.9 and $557.2 for the Company (excluding commitments between subsidiaries), Spire Missouri and Spire Alabama, respectively. Additional contracts are generally entered into prior to or during the heating season of November through April. The Utilities recover their costs from customers in accordance with their PGA clauses or GSA riders.

Spire is a limited partner in several unconsolidated partnerships, predominantly focusing on sustainability and development initiatives tied to the natural gas utility sector. Spire committed to contribute a total of $25.0 of capital to the partnerships as and when requested by the respective general partners. As of September 30, 2025, the total remaining unfunded commitment was $15.4.

Contingencies

The Company and the Utilities account for contingencies, including environmental liabilities, in accordance with accounting standards under the loss contingency guidance of ASC Topic 450, Contingencies, when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated.

In addition to matters noted below, the Company and the Utilities are involved in other litigation, claims, and investigations arising in the normal course of business. Management, after discussion with counsel, believes the final outcome will not have a material effect on the statements of income, balance sheets, and statements of cash flows of the Company, Spire Missouri, or Spire Alabama. However, there is uncertainty in the valuation of pending claims and prediction of litigation results.

The Company and the Utilities own and operate natural gas distribution, transmission, and storage facilities, the operations of which are subject to various environmental laws, regulations, and interpretations. While environmental issues resulting from such operations arise in the ordinary course of business, such issues have not materially affected the Company’s or Utilities’ financial position and results of operations. As environmental laws, regulations, and their interpretations change, the Company or the Utilities may incur additional environmental liabilities that may result in additional costs, which may be material.

In the natural gas industry, many gas distribution companies have incurred environmental liabilities associated with sites they or their predecessor companies formerly owned or operated where manufactured gas operations took place. The Utilities each have former manufactured gas plant ("MGP") operations in their respective service territories, some of which are discussed under the Spire Missouri and Spire Alabama headings below. To the extent costs are incurred associated with environmental remediation activities, the Utilities would request authority from their respective regulators to defer such costs (less any amounts received from insurance proceeds or as contributions from other potentially responsible parties (PRPs)) and collect them through future rates.

To date, costs incurred for all Spire MGP sites for investigation, remediation and monitoring have not been material. However, the amount of costs relative to future remedial actions at these and other sites is unknown and may be material. The actual future costs that Spire Missouri and Spire Alabama may incur could be materially higher or lower depending upon several factors, including whether remediation will be required, final selection and regulatory approval of any remedial actions, changing technologies and government regulations, the ultimate ability of other PRPs to pay, and any insurance recoveries.

In 2020, Spire retained an outside consultant to conduct probabilistic cost modeling of its former MGP sites in Missouri and Alabama. The purpose of this analysis was to develop an estimated range of probabilistic future liability for each of their MGP sites. That analysis, completed in March 2021, provided a range of demonstrated possible future expenditures to investigate, monitor and remediate the former MGP sites. Spire Missouri and Spire Alabama have recorded their best estimates of the probable expenditures that relate to these matters. The amount remains immaterial, and Spire Missouri, Spire Alabama and the Company do not expect potential liabilities that may arise from remediating these sites to have a material impact on their future financial condition or results of operations.

 

Spire Missouri

Spire Missouri has identified three former MGP sites in the city of St. Louis, Missouri (the “City”) where costs have been incurred and claims have been asserted. Spire Missouri has enrolled two of the sites in the Missouri Department of Natural Resources ("MoDNR") Brownfields/Voluntary Cleanup Program ("BVCP"). The third site is the result of an assertion by the United States Environmental Protection Agency ("EPA").

In conjunction with redevelopment of the Carondelet Coke site, Spire Missouri and another former owner of the site entered into an agreement (the “Remediation Agreement”) with the City development agencies, the developer, and an environmental consultant that obligates one of the City agencies and the environmental consultant to remediate the site and obtain a No Further Action ("NFA") letter from the MoDNR. The Remediation Agreement also provides for a release of Spire Missouri and the other former site owner from certain liabilities related to the past and current environmental condition of the site and requires the developer and the environmental consultant to maintain certain insurance coverage, including remediation cost containment, premises pollution liability, and professional liability. The operative provisions of the Remediation Agreement were triggered on December 20, 2010, on which date Spire Missouri and the other former site owner, as full consideration under the Remediation Agreement, paid a small percentage of the cost of remediation of the site. The property was divided into seven parcels, and MoDNR NFA letters have been received for six of the parcels. Remediation is ongoing on the last parcel.

 

In May 2023, Spire Missouri was approached by a real estate developer interested in purchasing the northern half of the second site, Station A, and developing the same for industrial purposes. Consequently, Spire Missouri entered into a cost sharing agreement for remedial investigation with other PRPs. The site developer, Spire Missouri and the PRPs collectively designed a site investigation plan which was submitted to the MoDNR and approved by the agency on August 27, 2024. A lead environmental engineering firm is now managing the ongoing site investigation process.

Additionally, in correspondence dated November 30, 2016, Region 7 of the EPA has asserted that Spire Missouri is liable under Section 107(a) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 ("CERCLA") for alleged coal gas waste contamination at a third site, Station B. Spire Missouri and the site owner notified the EPA that information and data provided by the EPA to date does not rise to the level of documenting a threat to the public health or environment. As such, in March 2017 Spire Missouri requested more information from the EPA. Spire Missouri never received a response from the EPA.

Spire Missouri has notified its insurers that it seeks reimbursement for costs incurred in the past and future potential liabilities associated with these MGP sites. While some of the insurers have denied coverage and reserved their rights, Spire Missouri retains the right to seek potential reimbursements from them.

On March 10, 2015, Spire Missouri received a Section 104(e) information request under CERCLA from EPA Region 7 regarding the former Thompson Chemical/Superior Solvents site in the City. In turn, Spire Missouri issued a Freedom of Information Act ("FOIA") request to the EPA on April 3, 2015, to identify the basis of the inquiry. The FOIA response from the EPA was received on July 15, 2015, and a response was provided to the EPA on August 15, 2015. Spire Missouri has received no further inquiry from the EPA regarding this matter.

In its western service area, Spire Missouri has six owned MGP sites enrolled in the BVCP, including Joplin MGP #1, St. Joseph MGP #1, Kansas City Coal Gas Station B, Kansas City Station A Railroad area, Kansas City Coal Gas Station A, and Independence MGP #2. Source removal has been conducted at all the owned sites since 2003 with the exception of Joplin. On September 15, 2016, a request was made with the MoDNR for a restrictive covenant use limitation with respect to Joplin. Remediation efforts at the six sites are at various stages of completion, ranging from groundwater monitoring and sampling following source removal activities to the aforementioned request for the Joplin site. As part of its participation in the BVCP, Spire Missouri communicates regularly with the MoDNR with respect to its remediation efforts and monitoring activities at these sites. On May 11, 2015, MoDNR approved the next phase of investigation at the Kansas City Station A Railroad area.

Spire Alabama

Spire Alabama is in the chain of title of nine former MGP sites, four of which it still owns, and five former manufactured gas distribution sites, one of which it still owns. All sites are located in the state of Alabama.

In 2011, a removal action was completed and an NFA letter was received at the Huntsville MGP site pursuant to an Administrative Settlement Agreement and Order on Consent among the EPA, Spire Alabama and the current site owner.

In 2012, Spire Alabama responded to an EPA Request for Information Pursuant to Section 104 of CERCLA relating to the 35th Avenue Superfund Site located in North Birmingham, Jefferson County, Alabama. Spire Alabama was identified as a PRP under CERCLA for the cleanup of the site or costs the EPA incurs in cleaning up the site. At this point, Spire Alabama has not been provided information that would allow it to determine the extent, if any, of its potential liability with respect to the 35th Avenue Superfund Site and vigorously denies its inclusion as a PRP.

Assessments were performed by the EPA of the former MGP sites in Gadsden and Anniston, and NFA letters were received after each assessment.

Spire

In addition to those discussed above for Spire Missouri and Spire Alabama, Spire is aware of the following contingent matters.

Spire Marketing, along with many natural gas industry participants, faced the unprecedented effects of Winter Storm Uri in February 2021. Numerous natural gas producers and midstream operators were unable to deliver natural gas to market as they experienced wellhead freeze-offs, power outages and equipment failure due to the extreme weather. These events resulted in supply curtailments, and related notices of force majeure to excuse performance, from and to certain counterparties. Further, these events made Spire Marketing subject to various commercial disputes, all of which have been settled and reflected in the financial statements in previous periods. As a result of participating in the Oklahoma natural gas market, Spire Marketing has become subject, along with other market participants, to a complaint filed in January 2025 by the State of Oklahoma related to its transactions with various counterparties in the state during this period. The

Company’s management continues to assess this matter but does not believe it will have a material impact on the Company’s financial position, results of operations or cash flow.
v3.25.3
Leases
 12 Months Ended
Sep. 30, 2025
Leases [Abstract]  
Leases

17. LEASES

The lease agreement covering the Company’s primary office space in St. Louis extends through February 2035, with an option to renew for an additional five years. Spire Alabama’s lease agreement for office space in Birmingham extends through January 2037, with an option to renew for two additional five-year terms. The lease agreement covering Spire Marketing and Spire Storage office space in Houston extends through December 2028, with options to terminate three years earlier or to renew for an additional five years. The renewal options in the St. Louis and Houston leases were deemed reasonably certain to be exercised and are included in the lease term used to determine the right-of-use assets and lease liabilities. The Company and its subsidiaries have other relatively minor rental arrangements for real estate and equipment with remaining terms of up to nine years.

Operating lease cost, cash flow and noncash information are shown in the following table.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Operating lease cost, including amounts
   capitalized

 

$

7.1

 

 

$

7.3

 

 

$

7.3

 

 

$

0.5

 

 

$

0.5

 

 

$

0.5

 

 

$

2.0

 

 

$

2.0

 

 

$

2.0

 

Operating cash flows representing cash
   paid for amounts included in the
   measurement of lease liabilities

 

 

7.3

 

 

 

7.4

 

 

 

7.3

 

 

 

0.5

 

 

 

0.5

 

 

 

0.5

 

 

 

2.2

 

 

 

2.1

 

 

 

2.1

 

Right-of-use assets obtained in exchange
   for lease liabilities

 

 

—

 

 

 

—

 

 

 

0.8

 

 

 

—

 

 

 

—

 

 

 

0.8

 

 

 

—

 

 

 

—

 

 

 

—

 

 

The following table shows year-end balance sheet and weighted-average information about operating leases.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Right-of-use assets

 

$

59.2

 

 

$

63.1

 

 

$

1.6

 

 

$

1.7

 

 

$

17.0

 

 

$

18.1

 

Lease liabilities, current

 

 

6.1

 

 

 

6.6

 

 

 

0.5

 

 

 

0.5

 

 

 

2.0

 

 

 

1.9

 

Lease liabilities, noncurrent

 

 

59.1

 

 

 

62.7

 

 

 

1.2

 

 

 

1.3

 

 

 

20.9

 

 

 

22.3

 

Weighted-average remaining lease term (in years)

 

 

12.6

 

 

 

13.5

 

 

 

4.8

 

 

 

5.1

 

 

 

11.3

 

 

 

12.3

 

Weighted-average discount rate

 

 

4.2

%

 

 

4.2

%

 

 

3.8

%

 

 

3.4

%

 

 

3.7

%

 

 

3.7

%

 

On the balance sheets, right-of-use assets are included in “Deferred Charges and Other Assets: Other,” current lease liabilities are in “Current Liabilities: Other,” and noncurrent lease liabilities are in “Deferred Credits and Other Liabilities: Other.”

Following is a maturity analysis by fiscal year for operating lease liabilities as of September 30, 2025.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

2026

 

$

6.3

 

 

$

0.5

 

 

$

2.0

 

2027

 

 

6.7

 

 

 

0.4

 

 

 

2.3

 

2028

 

 

6.8

 

 

 

0.3

 

 

 

2.3

 

2029

 

 

6.7

 

 

 

0.3

 

 

 

2.4

 

2030

 

 

6.7

 

 

 

0.2

 

 

 

2.4

 

Thereafter

 

 

51.3

 

 

 

0.2

 

 

 

16.9

 

Total undiscounted lease payments

 

 

84.5

 

 

 

1.9

 

 

 

28.3

 

Less present value discount

 

 

(19.3

)

 

 

(0.2

)

 

 

(5.4

)

Total current and noncurrent lease liabilities

 

$

65.2

 

 

$

1.7

 

 

$

22.9

 

 

There are no significant finance leases, short-term leases, subleases, variable lease payments, residual value guarantees, restrictions or covenants pertaining to leases.

The Company elected, for all asset classes, not to recognize right-of-use assets and lease liabilities for short-term leases. Instead, the lease payments for short-term leases are recognized in profit or loss on a straight-line basis over the lease term and variable lease payments are recognized in the period in which the obligation for those payments is incurred. The Company elected, for all asset classes, not to separate non-lease components from lease components and instead to account for each separate lease component and the non-lease components associated with that lease component as a single lease component.

The discount rate used for all the leases is the applicable incremental borrowing rate, which is the rate of interest that a lessee would have to pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. For a subsidiary lessee, the rate applicable to the subsidiary is used unless the lease terms are influenced by parent credit.
v3.25.3
Business Combinations
 12 Months Ended
Sep. 30, 2025
Business Combination [Abstract]  
Business Combination

18. BUSINESS COMBINATIONS

On January 19, 2024, a subsidiary in Spire’s Midstream segment acquired MoGas, an interstate natural gas pipeline, and Omega Pipeline, a connected gas distribution system in Missouri. MoGas interconnects with Spire STL Pipeline and other regional pipelines to deliver gas to Spire Missouri’s growing customer base in St. Charles, Franklin, and western St. Louis counties, among other utility, municipal, industrial and commercial customers. Omega owns and operates an approximately 75-mile natural gas distribution system within Fort Leonard Wood in south-central Missouri and is interconnected with the MoGas system. The acquisition was accounted for as a business combination in accordance with ASC 805, Business Combinations. The $176.1 purchase price was allocated almost entirely to property, plant and equipment based on their estimated fair value at the acquisition date and recorded as non-utility property in the consolidated balance sheet. The operating revenues and operating income of MoGas and Omega were not material to Spire’s consolidated results for the years ended September 30, 2025 or 2024.

Pending Acquisition

On July 27, 2025, Spire entered into an agreement with Piedmont Natural Gas, a wholly-owned subsidiary of Duke Energy, to acquire its Tennessee natural gas business. The purchase price is $2.48 billion in cash, subject to customary adjustments, including adjustments for net working capital, regulatory assets and liabilities, and capital expenditures at closing.

The acquisition is supported by a fully committed senior unsecured bridge facility, entered into on August 22, 2025, provided by a syndicate of banks led by BMO Capital Markets. The facility provides up to $2.48 billion in committed financing, consisting of a $1.88 billion bridge term loan and a $600 million delayed draw term loan. The loans bear interest at Adjusted Term SOFR plus 1.375% or Base Rate plus 0.375%, and mature 364 days after funding. As of September 30, 2025, the facility remains undrawn, and Spire does not currently anticipate drawing on it. The Company expects to permanently finance the transaction through a balanced mix of debt, equity, and hybrid securities.

In connection with the financing plan, Spire is considering selling its natural gas storage facilities, Spire Storage West LLC and Spire Storage Salt Plains LLC, to help fund the acquisition. The sale would be subject to board approval and customary closing conditions, including regulatory approval.

The Company expects the acquisition to significantly increase Spire’s scale of regulated business in one of the fastest growing regions in the U.S., expand regulatory diversity and provide accretive earnings and supports dividend growth. Upon closing, Piedmont’s Tennessee business will operate as Spire Tennessee.

The transaction is expected to close in the first quarter of calendar 2026, subject to customary closing conditions, including approval by the TPUC. On October 31, 2025, FERC approved the transfer of gas supply contracts to Spire. The applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act expired without objection, satisfying one of the key regulatory requirements for the transaction.
v3.25.3
Summary of Significant Accounting Policies (Policies)
 12 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]  
Basis of Presentation

BASIS OF PRESENTATION – These notes are an integral part of the accompanying audited financial statements of Spire Inc. (“Spire” or the “Company”) presented on a consolidated basis, Spire Missouri Inc. (“Spire Missouri”) and Spire Alabama Inc. (“Spire Alabama”). Spire Missouri, Spire Alabama and Spire EnergySouth Inc. (“Spire EnergySouth”) are wholly owned subsidiaries of Spire. Spire Missouri, Spire Alabama and the subsidiaries of Spire EnergySouth (Spire Gulf Inc. and Spire Mississippi Inc.) are collectively referred to as the “Utilities.” Unless otherwise indicated, references to years herein are references to the fiscal years ending September 30 for the Company and its subsidiaries.

The accompanying audited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The consolidated financial position, results of operations and cash flows of Spire include the accounts of the Company and all its subsidiaries. Transactions and balances between consolidated entities have been eliminated from the consolidated financial statements of Spire. In compliance with GAAP, transactions between Spire Missouri and Spire Alabama and their affiliates, as well as intercompany balances on their balance sheets, have not been eliminated from their separate financial statements.

NATURE OF OPERATIONS – Spire has three reportable segments: Gas Utility, Gas Marketing, and Midstream. The Gas Utility segment consists of the regulated natural gas distribution operations of the Company and is the core business segment of Spire in terms of revenue and earnings. The Gas Utility segment is comprised of the operations of: Spire Missouri, serving St. Louis, Kansas City, and other areas in Missouri; Spire Alabama, serving central and northern Alabama; and the subsidiaries of Spire EnergySouth, serving the Mobile, Alabama area and south-central Mississippi. The Gas Marketing segment includes Spire’s largest gas-related business, Spire Marketing Inc. (“Spire Marketing”), which provides non-regulated natural gas services throughout the United States (U.S.). The Midstream segment includes Spire Storage, Spire STL Pipeline and Spire MoGas Pipeline, which are subsidiaries engaged in the storage and transportation of natural gas. The activities of the Company’s other subsidiaries are reported as Other and are described in Note 14, Segment Information. Spire Missouri and Spire Alabama each have a single reportable segment.
Use of Estimates

USE OF ESTIMATES – The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
System of Accounts

SYSTEM OF ACCOUNTS – The accounts of the Utilities are maintained in accordance with the Uniform System of Accounts prescribed by the applicable state public service commissions, which systems substantially conform to those prescribed by FERC.
Regulated Operations

REGULATED OPERATIONS – The Utilities account for their regulated operations in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 980, Regulated Operations. This topic sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. The provisions of this accounting guidance require, among other things, that financial statements of a regulated enterprise reflect the actions of regulators, where appropriate. These actions may result in the recognition of revenues and expenses in time periods that are different than non-regulated enterprises. When this occurs, costs are deferred as assets in the balance sheet (regulatory assets) and recorded as expenses when those amounts are reflected in rates. In addition, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for recovery of costs that are expected to be incurred in the future (regulatory liabilities). Management believes that the current regulatory environment supports the continued use of these regulatory accounting principles and that all regulatory assets and regulatory liabilities are recoverable or refundable through the regulatory process. See additional discussion of regulated operations in Note 15, Regulatory Matters.
Property, Plant and Equipment

PROPERTY, PLANT, AND EQUIPMENT –

Utility Plant – Utility plant is comprised primarily of our utility distribution assets and amounts are stated at original cost. The cost of additions to utility plant includes contracted work, direct labor and materials, allocable overheads and an allowance for funds used during construction. The costs of units of property retired, replaced or renewed are removed from utility plant and are charged to accumulated depreciation. Maintenance and repairs of property and replacement and renewal of items determined to be less than units of property are charged to maintenance expenses. Utility plant includes $268.3 and $143.2 of construction work-in-process ("CWIP") for 2025 and 2024, respectively.

Utility plant is depreciated using the composite method on a straight-line basis over the estimated service lives of the various classes of property at rates approved by the applicable regulatory commission. For Spire Missouri and for Spire Alabama, the annual depreciation and amortization expense in fiscal years 2025, 2024 and 2023 averaged approximately 3% of the original cost of depreciable and amortizable property.

Non-utility Property – Non-utility property is comprised primarily of our storage facilities, transportation pipelines and other assets. These assets are recorded at the original cost of acquisition or construction, which includes material, labor, contractor services and, for FERC-regulated projects, an allowance for funds used during construction. Repairs, replacements and renewals of items of property determined to be less than a unit of property or that do not increase the property’s life or functionality are charged to maintenance expense. Upon retirement or sale of non-utility property, the original cost and related accumulated depreciation are removed from the accounts and any gain or loss is included in the income statements. Costs related to software developed or obtained for internal use are capitalized and amortized on a straight-line basis over the estimated useful life of the related software. If software is retired prior to being fully amortized, the difference is recorded as a loss in the income statements unless the unamortized balance is expected to be recovered through a regulatory deferral mechanism. Depreciation expense for non-utility property is recorded straight-line over the life of the asset. Depreciation expense for non-utility property was $32.7, $25.8, and $20.6 for 2025, 2024, and 2023, respectively. Non-utility property is as follows:

 

 

 

2025

 

 

2024

 

Storage

 

$

453.8

 

 

$

382.0

 

Pipeline

 

 

498.3

 

 

 

492.4

 

All Other Property*

 

 

184.5

 

 

 

177.7

 

Total property, plant and equipment

 

$

1,136.6

 

 

$

1,052.1

 

Accumulated depreciation

 

 

(129.4

)

 

 

(96.8

)

Property, plant and equipment, net

 

$

1,007.2

 

 

$

955.3

 

* Primarily consisting of computer software and hardware

 

 

 

 

 

 
Accrued Capital Expenditures

Accrued Capital Expenditures – Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid.

 

September 30

 

2025

 

 

2024

 

 

2023

 

Spire

 

$

82.5

 

 

$

116.5

 

 

$

104.3

 

Spire Missouri

 

 

61.8

 

 

 

67.4

 

 

 

56.5

 

Spire Alabama

 

 

9.5

 

 

 

14.1

 

 

 

4.6

 
Asset Retirement Obligations

ASSET RETIREMENT OBLIGATIONS – Spire, Spire Missouri and Spire Alabama record legal obligations associated with the retirement of long-lived assets in the period in which the obligations are incurred, if sufficient information exists to reasonably estimate the fair value of the obligations. Obligations are recorded as both a cost of the related long-lived asset and as a corresponding liability. Subsequently, the asset retirement costs are depreciated over the life of the asset and the asset retirement obligations are accreted to the expected settlement amounts. Spire, Spire Missouri and Spire Alabama record asset retirement obligations associated with certain safety requirements to purge and seal gas distribution mains upon retirement, the plugging and abandonment of storage wells and other storage facilities, specific service line obligations, and certain removal and disposal obligations related to components of Spire Missouri’s, Spire Alabama’s and Spire Gulf’s distribution systems and general plant. Asset retirement obligations recorded by Spire’s other subsidiaries are not material. As authorized by the MoPSC and the APSC, Spire Missouri, Spire Alabama and Spire Gulf accrue future asset removal costs associated with their property, plant and equipment even if a legal obligation does not exist. Such accruals are provided for through depreciation expense and are recorded with corresponding credits to regulatory liabilities or regulatory assets. When those utilities retire depreciable utility plant and equipment, they charge the associated original costs to accumulated depreciation and amortization, and any related removal costs incurred are charged to regulatory liabilities or regulatory assets. The difference between removal costs recognized in depreciation rates and the accretion expense and depreciation expense recognized for financial reporting purposes is a timing difference between recovery of these costs in rates and their recognition for financial reporting purposes. Accordingly, these differences are deferred as regulatory liabilities or regulatory assets. In the rate setting process, the regulatory liabilities or regulatory assets are excluded from the rate base upon which those utilities have the opportunity to earn their allowed rates of return.

The following table presents a reconciliation of the beginning and ending balances of asset retirement obligations at September 30, as reported in the balance sheets.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Asset retirement obligations, beginning of year

 

$

579.9

 

 

$

577.4

 

 

$

95.7

 

 

$

111.1

 

 

$

468.6

 

 

$

451.0

 

Liabilities incurred during the period

 

 

3.1

 

 

 

2.5

 

 

 

0.4

 

 

 

0.4

 

 

 

2.2

 

 

 

1.4

 

Liabilities settled during the period

 

 

(5.1

)

 

 

(6.5

)

 

 

(2.8

)

 

 

(2.9

)

 

 

(0.9

)

 

 

(1.3

)

Accretion

 

 

25.0

 

 

 

24.8

 

 

 

3.9

 

 

 

4.5

 

 

 

20.4

 

 

 

19.6

 

Revisions in estimated cash flows

 

 

(19.7

)

 

 

(18.3

)

 

 

(1.7

)

 

 

(17.4

)

 

 

(20.3

)

 

 

(2.1

)

Asset retirement obligations, end of year

 

$

583.2

 

 

$

579.9

 

 

$

95.5

 

 

$

95.7

 

 

$

470.0

 

 

$

468.6

 
Natural Gas and Propane Gas

NATURAL GAS AND PROPANE GAS – For Spire Missouri’s eastern region, inventory of natural gas in storage is priced on a last in, first out (LIFO) basis and inventory of propane gas in storage is priced on a first in, first out (FIFO) basis. For the rest of the Gas Utility segment, inventory of natural gas in storage is priced on the weighted average cost basis. The replacement cost of Spire Missouri’s natural gas for current use in eastern Missouri at September 30, 2025 and 2024 was less than the LIFO cost by $21.3 and $27.3, respectively. The carrying value of the Utilities’ inventory is never adjusted to a lower net realizable value or market value because, pursuant to PGA clauses or a GSA rider, actual gas costs are recovered in customer rates. Natural gas and propane gas storage inventory in Spire’s other segments is recorded at the lower of average cost or net realizable value.
Goodwill

GOODWILL – Spire’s acquisitions were accounted for using business combination accounting. Under this method, the purchase price paid by the acquirer is allocated to the assets acquired and liabilities assumed as of the acquisition date based on their fair value. Goodwill is measured as the excess of the acquisition-date fair value of the consideration transferred over the amount of acquisition-date identifiable assets acquired net of assumed liabilities. At September 30, 2025, goodwill included in Spire’s Gas Utility, Gas Marketing, and Midstream segments was $210.2, zero, and zero, respectively, with the remainder held at the corporate level. Goodwill amounts have not changed since fiscal 2017, and there are no accumulated impairment losses. Spire and Spire Missouri evaluate goodwill for impairment as of July 1 of each year, or more frequently if events and circumstances indicate that goodwill might be impaired. At each test date, the assessments concluded that goodwill was not impaired. The Company updated the assessments as of September 30, 2025, determining that it remained more likely than not that the fair value of each reporting unit exceeded its carrying value.
Impairment of Long-Lived Assets

IMPAIRMENT OF LONG-LIVED ASSETS – Long-lived assets classified as held and used are evaluated for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Whether impairment has occurred is determined by comparing the estimated undiscounted cash flows attributable to the assets with the carrying value of the assets. If the carrying value exceeds the undiscounted cash flows, the Company recognizes an impairment charge equal to the amount of the carrying value that exceeds the estimated fair value of the assets. In the period in which the Company determines an asset meets held-for-sale criteria, an impairment charge is recorded to the extent the book value exceeds its fair value less cost to sell.
Derivatives

DERIVATIVES – In the course of their business, certain subsidiaries of Spire enter into commitments associated with the purchase or sale of natural gas. Certain of their derivative natural gas contracts are designated as normal purchases or normal sales and, as such, are excluded from the scope of FASB ASC Topic 815, Derivatives and Hedging. Those contracts are accounted for as executory contracts and recorded on an accrual basis. Revenues and expenses from such contracts are recorded gross. Contracts not designated as normal purchases or normal sales are recorded as derivatives with changes in fair value recognized in earnings in the periods prior to physical delivery. Certain of Spire Marketing’s wholesale purchase and sale transactions are classified as trading activities for financial reporting purposes, with income and expenses presented on a net basis in natural gas expenses in the Consolidated Statements of Income. Spire also enters into cash flow hedges through execution of interest rate swap contracts to protect itself against adverse movements in interest rates. In the first quarter of fiscal 2024, considering changes in debt issuance strategy due to the interest rate environment, Spire management determined it was probable the anticipated issuance of certain debt, and therefore the hedged forecasted interest payments, would not occur. The related swap was settled, hedge accounting was discontinued, and amounts previously deferred in “Accumulated other comprehensive income” were reclassified to earnings, such that the entire realized gain of $8.2 was included in “Other income” for Spire Inc. in the quarter ended December 31, 2023. Refer to Note 10, Derivative Instruments and Hedging Activities, for more information about derivatives.
Income Taxes

INCOME TAXES – Spire and its subsidiaries account for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amount of existing assets and liabilities and the respective tax basis and for tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be realized or settled. The effects on deferred tax assets and liabilities of a change in enacted tax rates is recognized in income or loss for non-regulated operations, and in a regulatory asset or regulatory liability for regulated operations. A valuation allowance is established when it is more likely than not that some portion or all of the deferred tax assets will not be realized.

The Company accounts for uncertain tax positions in accordance with authoritative guidance. The authoritative guidance addresses the determination of whether tax benefits claimed, or expected to be claimed, on a tax return should be recorded in the financial statements. Spire may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the position will be sustained upon examination by the taxing authority, based on the technical merits of the position. Tax-related interest and penalties, if any, are classified as a liability on the balance sheets. For additional information on the accounting for income taxes, refer to Note 12, Income Taxes.
Cash, Cash equivalents and Restricted Cash

CASH, CASH EQUIVALENTS, AND RESTRICTED CASH – All highly liquid debt instruments purchased with original maturities of three months or less are considered to be cash equivalents. Such instruments are carried at cost, which approximates market value. Outstanding checks on the Company’s and Utilities’ bank accounts in excess of funds on deposit create book overdrafts (which are funded at the time checks are presented for payment) and are classified as Other in the Current Liabilities section of the balance sheets. Changes in book overdrafts are reflected as Operating Activities in the statements of cash flows.

In Spire’s statements of cash flows, total Cash, Cash Equivalents, and Restricted Cash included $35.5 and $30.4 of restricted cash reported in “Other Investments” on the Company’s balance sheet as of September 30, 2025 and 2024, respectively (in addition to amounts shown as “Cash and cash equivalents”). This restricted cash has been segregated and invested in debt securities in trust accounts based on collateral requirements for reinsurance at Spire’s risk management company.
Natural Gas Receivable

NATURAL GAS RECEIVABLE – Spire Marketing enters into natural gas transactions with natural gas pipeline and storage companies known as park and loan arrangements. Under the terms of the arrangements, Spire Marketing purchases natural gas from a third party and delivers that natural gas to the pipeline or storage company for the right to receive the same quantity of natural gas from that company at the same location in a future period. These arrangements are accounted for as non-monetary transactions under GAAP and are recorded at the carrying amount. As such, natural gas receivables are reflected in “Other” current assets on the Consolidated Balance Sheets at cost, which includes related fees associated with the transactions. In the period that the natural gas is returned to Spire Marketing, concurrent with the sale of the natural gas to a third party, the related natural gas receivable is expensed in the Consolidated Statements of Income. In conjunction with these transactions, Spire Marketing usually enters into New York Mercantile Exchange (NYMEX) and Intercontinental Exchange (ICE) natural gas futures, options, and swap contracts or fixed price sales agreements to protect against market changes in future sales prices.
Earnings Per Common Share

EARNINGS PER COMMON SHARE – GAAP requires dual presentation of basic and diluted earnings per share (EPS). EPS is computed using the two-class method, which is an earnings allocation method for computing EPS that treats a participating security as having rights to earnings that would otherwise have been available to common shareholders. Certain of the Company’s stock-based compensation awards pay non-forfeitable dividends to the participants during the vesting period and, as such, are deemed participating securities. Basic EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding that are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common shares, pursuant to the treasury stock method. Shares attributable to equity units, common stock forward purchase contracts, non-participating performance-contingent restricted stock awards, and time-vested restricted stock/units are excluded from the calculation of diluted earnings per share if the effect would be antidilutive. Shares attributable to non-participating performance-contingent restricted stock awards are only included in the calculation of diluted earnings per share to the extent the underlying performance and/or market conditions are satisfied (a) prior to the end of the reporting period or (b) would be satisfied if the end of the reporting period were the end of the related contingency period and the result would be dilutive. The Company’s EPS computations are presented in Note 4, Earnings Per Common Share.
Transactions with Affiliates

TRANSACTIONS WITH AFFILIATES – Transactions between affiliates of the Company have been eliminated from the consolidated financial statements of Spire. Spire Missouri and Spire Alabama borrowed funds from the Company and incurred related interest, as reflected in their separate financial statements, and they participated in normal intercompany shared services transactions. In addition, Spire Missouri’s and Spire Alabama’s other transactions with affiliates included:

 

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Natural gas purchases from Spire Marketing

 

$

23.8

 

 

$

13.9

 

 

$

57.4

 

 

$

13.9

 

 

$

6.7

 

 

$

4.7

 

Natural gas sales to Spire Marketing

 

 

0.1

 

 

 

1.7

 

 

 

0.4

 

 

 

—

 

 

 

—

 

 

 

—

 

Transportation services from Spire STL Pipeline LLC

 

 

32.0

 

 

 

32.5

 

 

 

32.0

 

 

 

—

 

 

 

—

 

 

 

—

 

Natural gas storage services from Spire Storage Salt Plains
   LLC

 

 

—

 

 

 

0.7

 

 

 

0.7

 

 

 

—

 

 

 

—

 

 

 

—

 

Transportation services from Spire MoGas Pipeline LLC

 

 

7.0

 

 

 

4.8

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 
Accounts Receivable and Allowance for Credit Losses

ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES – Trade accounts receivable are recorded at the amounts due from customers, including unbilled amounts. Accounts receivable are written off when they are deemed to be uncollectible. An allowance for expected credit losses is estimated and updated based on relevant data and trends such as accounts receivable aging, historical write-off experience, current write-off trends, economic conditions, and the impact of weather and availability of customer payment assistance on collection trends. For the Utilities, net write-offs as a percentage of revenue has historically been the best predictor of base net write-off experience over time. Management judgment is applied in the development of the allowance due to the complexity of variables and subjective nature of certain relevant factors. The accounts receivable of Spire’s non-utility businesses are evaluated separately from those of the Utilities. The allowance for credit losses for those other businesses is based on a continuous evaluation of the individual counterparty risk and is not significant for the periods presented. Activity in the allowance for credit losses is shown in the following table.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Allowance at beginning of year

 

$

31.4

 

 

$

32.5

 

 

$

31.9

 

 

$

24.9

 

 

$

26.2

 

 

$

24.9

 

 

$

5.7

 

 

$

5.7

 

 

$

6.3

 

Provision for expected credit losses

 

 

19.6

 

 

 

23.0

 

 

 

16.6

 

 

 

14.8

 

 

 

19.0

 

 

 

13.3

 

 

 

4.0

 

 

 

3.2

 

 

 

2.6

 

Write-offs, net of recoveries

 

 

(22.2

)

 

 

(24.1

)

 

 

(16.0

)

 

 

(16.7

)

 

 

(20.3

)

 

 

(12.0

)

 

 

(4.8

)

 

 

(3.2

)

 

 

(3.2

)

Allowance at end of year

 

$

28.8

 

 

$

31.4

 

 

$

32.5

 

 

$

23.0

 

 

$

24.9

 

 

$

26.2

 

 

$

4.9

 

 

$

5.7

 

 

$

5.7

 

 

FINANCE RECEIVABLES – Spire Alabama finances third party contractor sales of merchandise including gas furnaces and appliances. At September 30, 2025 and 2024, Spire Alabama’s finance receivable totaled approximately $5.4 and $5.9, respectively. Financing is available only to qualified customers who meet creditworthiness thresholds for customer payment history and external agency credit reports. Spire Alabama relies upon ongoing payments as the primary indicator of credit quality during the term of each contract. The allowance for credit losses is recognized using an estimate of write-off percentages based on historical experience. Delinquent accounts are evaluated on a case-by-case basis and, absent evidence of debt repayment, after 90 days are due in full and assigned to a third-party collection agency. The remaining finance receivable is written off approximately 12 months after being assigned to the third-party collection agency. Spire Alabama had finance receivables past due 90 days or more of $0.4 and $0.4 at September 30, 2025 and 2024, respectively.
Group Medical and Workers' Compensation Reserves

GROUP MEDICAL AND WORKERS’ COMPENSATION RESERVES – The Company self-insures its group medical and workers’ compensation costs and carries stop-loss coverage in relation to medical claims and workers’ compensation claims. Reserves for amounts incurred but not reported are established based on historical cost levels and lags between occurrences and reporting.
Fair Value Measurements

FAIR VALUE MEASUREMENTS – Certain assets and liabilities are recognized or disclosed at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value.

The levels of the hierarchy are described below:

•
Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities.
•
Level 2 – Pricing inputs other than quoted prices included within Level 1, which are either directly or indirectly observable for the asset or liability as of the reporting date. These inputs are derived principally from, or corroborated by, observable market data.
•
Level 3 – Pricing that is based upon inputs that are generally unobservable that are based on the best information available and reflect management’s assumptions about how market participants would price the asset or liability.

Assessment of the significance of a particular input to the fair value measurements may require judgment and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. Additional information about fair value measurements is provided in Note 8, Fair Value of Financial Instruments, Note 9, Fair Value Measurements, and Note 13, Pension Plans and Other Postretirement Benefits.
Stock-Based Compensation

STOCK-BASED COMPENSATION – The Company accounts for share-based compensation arrangements in accordance with ASC Topic 718, Compensation – Stock Compensation. The Company measures stock-based compensation awards at fair value at the date of grant and recognizes the compensation cost of the awards over the requisite service period. Forfeitures are recognized in the period they occur. Refer to Note 3, Stock-Based Compensation, for further discussion of the accounting for the Company’s stock-based compensation plans.
New Accounting Pronouncements

NEW ACCOUNTING PRONOUNCEMENTS - On September 30, 2025, the Companies adopted ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which updates segment disclosure requirements through enhanced disclosures around significant segment expenses. The Companies applied the provision retrospectively to all periods presented for each reportable segment as further described. Refer to Note 14, for further discussion of segment reporting.

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income (Topic 220): Expense Disaggregation Disclosures (“ASU 2024-03”). This ASU improves disclosure of a public business entity’s expense by requiring disaggregated disclosure of expenses in commonly presented expense captions. ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and for interim periods beginning after December 15, 2027. Early adoption is permitted. The Companies are currently evaluating the impact of this ASU on their respective consolidated financial statements.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”). This ASU enhances the transparency of income tax disclosures related to rate reconciliation and income taxes. ASU 2023-09 is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. The Companies are currently evaluating the impact of this ASU on their respective consolidated financial statements.

Management believes that all other recently adopted and recently issued accounting standards that are not yet effective will not have a material impact on the Companies financial position, results of operations or cash flows upon adoption.
v3.25.3
Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]  
Summary of Non-Utility Property Non-utility property is as follows:

 

 

 

2025

 

 

2024

 

Storage

 

$

453.8

 

 

$

382.0

 

Pipeline

 

 

498.3

 

 

 

492.4

 

All Other Property*

 

 

184.5

 

 

 

177.7

 

Total property, plant and equipment

 

$

1,136.6

 

 

$

1,052.1

 

Accumulated depreciation

 

 

(129.4

)

 

 

(96.8

)

Property, plant and equipment, net

 

$

1,007.2

 

 

$

955.3

 

* Primarily consisting of computer software and hardware

 

 

 

 

 

 
Schedule of Capital Expenditure Excluded From Statement of Cash Flow

September 30

 

2025

 

 

2024

 

 

2023

 

Spire

 

$

82.5

 

 

$

116.5

 

 

$

104.3

 

Spire Missouri

 

 

61.8

 

 

 

67.4

 

 

 

56.5

 

Spire Alabama

 

 

9.5

 

 

 

14.1

 

 

 

4.6

 
Schedule of Asset Retirement Obligations

The following table presents a reconciliation of the beginning and ending balances of asset retirement obligations at September 30, as reported in the balance sheets.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Asset retirement obligations, beginning of year

 

$

579.9

 

 

$

577.4

 

 

$

95.7

 

 

$

111.1

 

 

$

468.6

 

 

$

451.0

 

Liabilities incurred during the period

 

 

3.1

 

 

 

2.5

 

 

 

0.4

 

 

 

0.4

 

 

 

2.2

 

 

 

1.4

 

Liabilities settled during the period

 

 

(5.1

)

 

 

(6.5

)

 

 

(2.8

)

 

 

(2.9

)

 

 

(0.9

)

 

 

(1.3

)

Accretion

 

 

25.0

 

 

 

24.8

 

 

 

3.9

 

 

 

4.5

 

 

 

20.4

 

 

 

19.6

 

Revisions in estimated cash flows

 

 

(19.7

)

 

 

(18.3

)

 

 

(1.7

)

 

 

(17.4

)

 

 

(20.3

)

 

 

(2.1

)

Asset retirement obligations, end of year

 

$

583.2

 

 

$

579.9

 

 

$

95.5

 

 

$

95.7

 

 

$

470.0

 

 

$

468.6

 
Schedule of Related Party Transactions

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Natural gas purchases from Spire Marketing

 

$

23.8

 

 

$

13.9

 

 

$

57.4

 

 

$

13.9

 

 

$

6.7

 

 

$

4.7

 

Natural gas sales to Spire Marketing

 

 

0.1

 

 

 

1.7

 

 

 

0.4

 

 

 

—

 

 

 

—

 

 

 

—

 

Transportation services from Spire STL Pipeline LLC

 

 

32.0

 

 

 

32.5

 

 

 

32.0

 

 

 

—

 

 

 

—

 

 

 

—

 

Natural gas storage services from Spire Storage Salt Plains
   LLC

 

 

—

 

 

 

0.7

 

 

 

0.7

 

 

 

—

 

 

 

—

 

 

 

—

 

Transportation services from Spire MoGas Pipeline LLC

 

 

7.0

 

 

 

4.8

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 
Accounts Receivable, Allowance for Credit Loss

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Allowance at beginning of year

 

$

31.4

 

 

$

32.5

 

 

$

31.9

 

 

$

24.9

 

 

$

26.2

 

 

$

24.9

 

 

$

5.7

 

 

$

5.7

 

 

$

6.3

 

Provision for expected credit losses

 

 

19.6

 

 

 

23.0

 

 

 

16.6

 

 

 

14.8

 

 

 

19.0

 

 

 

13.3

 

 

 

4.0

 

 

 

3.2

 

 

 

2.6

 

Write-offs, net of recoveries

 

 

(22.2

)

 

 

(24.1

)

 

 

(16.0

)

 

 

(16.7

)

 

 

(20.3

)

 

 

(12.0

)

 

 

(4.8

)

 

 

(3.2

)

 

 

(3.2

)

Allowance at end of year

 

$

28.8

 

 

$

31.4

 

 

$

32.5

 

 

$

23.0

 

 

$

24.9

 

 

$

26.2

 

 

$

4.9

 

 

$

5.7

 

 

$

5.7

 
v3.25.3
Revenue (Tables)
 12 Months Ended
Sep. 30, 2025
Revenue from Contract with Customer [Abstract]  
Schedule of Revenue Disaggregated by Source and Customer Type

 

 

2025

 

 

2024

 

 

2023

 

Spire

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

Residential

 

$

1,462.6

 

 

$

1,617.4

 

 

$

1,648.5

 

Commercial & industrial

 

 

501.3

 

 

 

581.0

 

 

 

606.0

 

Transportation

 

 

133.6

 

 

 

130.0

 

 

 

121.6

 

Off-system & other incentive

 

 

65.3

 

 

 

37.0

 

 

 

30.0

 

Other customer revenue

 

 

24.4

 

 

 

21.2

 

 

 

16.1

 

Total revenue from contracts with customers

 

 

2,187.2

 

 

 

2,386.6

 

 

 

2,422.2

 

Changes in accrued revenue under alternative revenue programs

 

 

20.3

 

 

 

51.3

 

 

 

34.7

 

Total Gas Utility operating revenues

 

 

2,207.5

 

 

 

2,437.9

 

 

 

2,456.9

 

Gas Marketing

 

 

157.2

 

 

 

99.2

 

 

 

179.1

 

Midstream

 

 

155.5

 

 

 

100.7

 

 

 

66.1

 

Other

 

 

20.6

 

 

 

17.6

 

 

 

16.7

 

Total before eliminations

 

 

2,540.8

 

 

 

2,655.4

 

 

 

2,718.8

 

Intercompany eliminations

 

 

(64.4

)

 

 

(62.4

)

 

 

(52.5

)

Total Operating Revenues

 

$

2,476.4

 

 

$

2,593.0

 

 

$

2,666.3

 

Spire Missouri

 

 

 

 

 

 

 

 

 

Residential

 

$

1,092.1

 

 

$

1,217.7

 

 

$

1,261.3

 

Commercial & industrial

 

 

326.0

 

 

 

390.9

 

 

 

411.9

 

Transportation

 

 

35.9

 

 

 

34.1

 

 

 

33.2

 

Off-system & other incentive

 

 

51.9

 

 

 

28.8

 

 

 

20.1

 

Other customer revenue

 

 

14.0

 

 

 

14.9

 

 

 

12.5

 

Total revenue from contracts with customers

 

 

1,519.9

 

 

 

1,686.4

 

 

 

1,739.0

 

Changes in accrued revenue under alternative revenue programs

 

 

24.2

 

 

 

51.0

 

 

 

23.9

 

Total Operating Revenues

 

$

1,544.1

 

 

$

1,737.4

 

 

$

1,762.9

 

Spire Alabama

 

 

 

 

 

 

 

 

 

Residential

 

$

307.5

 

 

$

336.4

 

 

$

322.9

 

Commercial & industrial

 

 

134.5

 

 

 

149.5

 

 

 

150.4

 

Transportation

 

 

87.3

 

 

 

85.1

 

 

 

77.6

 

Off-system & other incentive

 

 

13.4

 

 

 

8.1

 

 

 

9.9

 

Other customer revenue

 

 

6.3

 

 

 

(0.4

)

 

 

3.6

 

Total revenue from contracts with customers

 

 

549.0

 

 

 

578.7

 

 

 

564.4

 

Changes in accrued revenue under alternative revenue programs

 

 

(3.8

)

 

 

0.2

 

 

 

6.7

 

Total Operating Revenues

 

$

545.2

 

 

$

578.9

 

 

$

571.1

 
Schedule of Gross Receipts Taxes Associated Revenues

 

 

2025

 

 

2024

 

 

2023

 

Spire

 

$

115.7

 

 

$

128.2

 

 

$

131.8

 

Spire Missouri

 

 

82.9

 

 

 

93.1

 

 

 

96.7

 

Spire Alabama

 

 

27.9

 

 

 

30.1

 

 

 

29.9

 
v3.25.3
Stock-based Compensation (Tables)
 12 Months Ended
Sep. 30, 2025
Share-Based Payment Arrangement [Abstract]  
Schedule Of Restricted Stock and Restricted Stock Unit Activity

Fiscal 2025 activity of restricted stock units subject to performance and/or market conditions is presented below:

 

 

 

Units

 

 

Weighted
Average
Grant Date
Fair Value
Per Unit

 

Non-vested at September 30, 2024

 

 

289,205

 

 

$

73.36

 

Granted

 

 

103,780

 

 

$

76.52

 

Adjusted for performance

 

 

21,469

 

 

$

65.02

 

Vested

 

 

(100,784

)

 

$

65.02

 

Forfeited

 

 

(69,166

)

 

$

74.67

 

Non-vested at September 30, 2025

 

 

244,504

 

 

$

75.62

 

Time-vested restricted stock and stock unit activity for fiscal 2025 is presented below:

 

 

 

Shares/
Units

 

 

Weighted
Average
Grant Date
Fair Value
Per Share

 

Non-vested at September 30, 2024

 

 

85,559

 

 

$

64.13

 

Granted

 

 

57,030

 

 

$

72.00

 

Vested

 

 

(42,677

)

 

$

66.36

 

Forfeited

 

 

(23,348

)

 

$

67.61

 

Non-vested at September 30, 2025

 

 

76,564

 

 

$

67.20

 
Schedule Of Stock Option Valuation Assumptions The significant assumptions used in the Monte Carlo simulations are as follows:

 

 

 

2025

 

2024

 

2023

Risk-free interest rate

 

4.33%

 

4.66%

 

4.26%

Expected dividend yield of stock

 

—

 

—

 

—

Expected volatility of stock

 

22.2%

 

23.3%

 

33.8%

Performance period (in years)

 

3.0

 

3.0

 

3.0
Schedule Of Share-based Compensation Arrangement, Expensed and Capitalized

The amounts of compensation cost recognized for share-based compensation arrangements are presented below:

 

 

 

2025

 

 

2024

 

 

2023

 

Total compensation cost

 

$

7.8

 

 

$

6.6

 

 

$

11.2

 

Compensation cost capitalized

 

 

(1.1

)

 

 

(0.8

)

 

 

(1.4

)

Compensation cost recognized in net income

 

 

6.7

 

 

 

5.8

 

 

 

9.8

 

Income tax benefit recognized in net income

 

 

(1.5

)

 

 

(1.3

)

 

 

(2.2

)

Compensation cost recognized in net income, net of income tax

 

$

5.2

 

 

$

4.5

 

 

$

7.6

 
v3.25.3
Earnings Per Common Share (Tables)
 12 Months Ended
Sep. 30, 2025
Earnings Per Share [Abstract]  
Schedule of Earnings Per Common Share

 

 

2025

 

 

2024

 

 

2023

 

Basic Earnings Per Common Share:

 

 

 

 

 

 

 

 

 

Net Income

 

$

271.7

 

 

$

250.9

 

 

$

217.5

 

Less: Provision for preferred dividends

 

 

14.8

 

 

 

14.8

 

 

 

14.8

 

Income allocated to participating securities

 

 

0.3

 

 

 

0.3

 

 

 

0.3

 

Net Income Available to Common Shareholders

 

$

256.6

 

 

$

235.8

 

 

$

202.4

 

Weighted Average Common Shares Outstanding (in millions)

 

 

58.5

 

 

 

56.1

 

 

 

52.5

 

Basic Earnings Per Share of Common Stock

 

$

4.39

 

 

$

4.20

 

 

$

3.86

 

Diluted Earnings per Common Share:

 

 

 

 

 

 

 

 

 

Net Income

 

$

271.7

 

 

$

250.9

 

 

$

217.5

 

Less: Provision for preferred dividends

 

 

14.8

 

 

 

14.8

 

 

 

14.8

 

Income allocated to participating securities

 

 

0.3

 

 

 

0.3

 

 

 

0.3

 

Net Income Available to Common Shareholders

 

$

256.6

 

 

$

235.8

 

 

$

202.4

 

Weighted Average Common Shares Outstanding (in millions)

 

 

58.5

 

 

 

56.1

 

 

 

52.5

 

Dilutive Effect of Restricted Stock and Restricted Stock Units
   (in millions)*

 

 

0.2

 

 

 

0.2

 

 

 

0.1

 

Weighted Average Diluted Common Shares (in millions)

 

 

58.7

 

 

 

56.3

 

 

 

52.6

 

Diluted Earnings Per Share of Common Stock

 

$

4.37

 

 

$

4.19

 

 

$

3.85

 

 

 

 

 

 

 

 

 

 

 

* Calculation excludes certain outstanding common shares (shown in
   millions by period at the right) attributable to common stock forward
   contracts, stock units subject to performance or market conditions, and
   restricted stock, which could have a dilutive effect in the future

 

 

0.2

 

 

 

0.1

 

 

 

1.9

 
v3.25.3
Shareholders' Equity (Tables)
 12 Months Ended
Sep. 30, 2025
Shareholders' Equity  
Schedule of Accumulated Other Comprehensive Income (Loss)

 

 

Net

 

 

Defined Benefit

 

 

Net Unrealized

 

 

 

 

 

 

Unrealized

 

 

Pension and

 

 

Gain (Loss) on

 

 

 

 

 

 

Gain (Loss)

 

 

Other

 

 

Available-for-

 

 

 

 

 

 

on Cash Flow

 

 

Postretirement

 

 

Sale Debt

 

 

 

 

 

 

Hedges

 

 

Benefit Plans

 

 

Securities

 

 

Total

 

Spire

 

 

 

 

 

 

 

 

 

 

 

 

Balance at September 30, 2023

 

$

50.5

 

 

$

(2.5

)

 

$

(0.4

)

 

$

47.6

 

Other comprehensive (loss) income

 

 

(36.3

)

 

 

0.5

 

 

 

0.3

 

 

 

(35.5

)

Balance at September 30, 2024

 

 

14.2

 

 

 

(2.0

)

 

 

(0.1

)

 

 

12.1

 

Other comprehensive income

 

 

5.9

 

 

 

1.3

 

 

 

0.1

 

 

 

7.3

 

Balance at September 30, 2025

 

$

20.1

 

 

$

(0.7

)

 

$

—

 

 

$

19.4

 

 

 

 

 

 

 

 

 

 

 

 

 

Spire Missouri

 

 

 

 

 

 

 

 

 

 

 

 

Balance at September 30, 2023

 

$

—

 

 

$

(2.5

)

 

$

—

 

 

$

(2.5

)

Other comprehensive income

 

 

—

 

 

 

0.5

 

 

 

—

 

 

 

0.5

 

Balance at September 30, 2024

 

 

—

 

 

 

(2.0

)

 

 

—

 

 

 

(2.0

)

Other comprehensive income

 

 

—

 

 

 

1.3

 

 

 

—

 

 

 

1.3

 

Balance at September 30, 2025

 

$

—

 

 

$

(0.7

)

 

$

—

 

 

$

(0.7

)
v3.25.3
Long-term Debt (Tables)
 12 Months Ended
Sep. 30, 2025
Debt Disclosure [Abstract]  
Schedule of Long-Term Debt Instruments

The composition of long-term debt as of September 30 is shown in the following tables.

 

 

 

2025

 

 

2024

 

Spire

 

 

 

 

 

 

5.30% Senior Notes, due March 1, 2026

 

$

350.0

 

 

$

350.0

 

3.13% Senior Notes, due September 1, 2026

 

 

130.0

 

 

 

130.0

 

3.93% Senior Notes, due March 15, 2027

 

 

100.0

 

 

 

100.0

 

5.80% Senior Notes, due March 15, 2033

 

 

150.0

 

 

 

150.0

 

4.70% Senior Notes, due August 15, 2044

 

 

250.0

 

 

 

250.0

 

Total principal of Spire Missouri long-term debt (see below)

 

 

1,968.0

 

 

 

1,818.0

 

Total principal of Spire Alabama long-term debt (see below)

 

 

715.0

 

 

 

750.0

 

Other subsidiaries' long-term debt:

 

 

 

 

 

 

5.00% First Mortgage Bonds, due September 30, 2031

 

 

42.0

 

 

 

42.0

 

2.95% Notes, with annual principal payments through December 2034

 

 

104.1

 

 

 

111.1

 

5.61% First Mortgage Bonds, due October 15, 2037

 

 

30.0

 

 

 

30.0

 

3.52% First Mortgage Bonds, due September 30, 2049

 

 

40.0

 

 

 

40.0

 

Total principal of long-term debt

 

 

3,879.1

 

 

 

3,771.1

 

Less: Unamortized discounts and debt issuance costs

 

 

(22.2

)

 

 

(24.7

)

Less: Current portion

 

 

(487.5

)

 

 

(42.0

)

Long-term debt, excluding current portion

 

$

3,369.4

 

 

$

3,704.4

 

Spire Missouri

 

 

 

 

 

 

First Mortgage Bonds:

 

 

 

 

 

 

3.40% Series, due March 15, 2028

 

$

45.0

 

 

$

45.0

 

7.00% Series, due June 1, 2029

 

 

19.3

 

 

 

19.3

 

2.84% Series, due November 15, 2029

 

 

275.0

 

 

 

275.0

 

4.88% Series, due September 15, 2030

 

 

90.0

 

 

 

—

 

7.90% Series, due September 15, 2030

 

 

30.0

 

 

 

30.0

 

5.12% Series, due September 15, 2032

 

 

60.0

 

 

 

—

 

3.68% Series, due September 15, 2032

 

 

50.0

 

 

 

50.0

 

4.80% Series, due February 15, 2033

 

 

400.0

 

 

 

400.0

 

6.00% Series, due May 1, 2034

 

 

99.3

 

 

 

99.3

 

5.15% Series, due August 15, 2034

 

 

320.0

 

 

 

320.0

 

6.15% Series, due June 1, 2036

 

 

54.5

 

 

 

54.5

 

4.63% Series, due August 15, 2043

 

 

99.9

 

 

 

99.9

 

4.23% Series, due September 15, 2047

 

 

70.0

 

 

 

70.0

 

3.30% Series, due June 1, 2051

 

 

305.0

 

 

 

305.0

 

4.38% Series, due September 15, 2057

 

 

50.0

 

 

 

50.0

 

Total principal of Spire Missouri long-term debt

 

 

1,968.0

 

 

 

1,818.0

 

Less: Unamortized discounts and debt issuance costs

 

 

(14.4

)

 

 

(14.6

)

Spire Missouri long-term debt, excluding current portion

 

$

1,953.6

 

 

$

1,803.4

 

Spire Alabama

 

 

 

 

 

 

3.21% Notes, due September 15, 2025

 

$

—

 

 

$

35.0

 

5.32% Notes, due October 15, 2029

 

 

90.0

 

 

 

90.0

 

2.88% Notes, due December 1, 2029

 

 

100.0

 

 

 

100.0

 

2.04% Notes, due December 15, 2030

 

 

150.0

 

 

 

150.0

 

5.41% Notes, due October 15, 2032

 

 

85.0

 

 

 

85.0

 

5.90% Notes, due January 15, 2037

 

 

45.0

 

 

 

45.0

 

4.31% Notes, due December 1, 2045

 

 

80.0

 

 

 

80.0

 

3.92% Notes, due January 15, 2048

 

 

45.0

 

 

 

45.0

 

4.64% Notes, due January 15, 2049

 

 

90.0

 

 

 

90.0

 

4.02% Notes, due January 15, 2058

 

 

30.0

 

 

 

30.0

 

Total principal of Spire Alabama long-term debt

 

 

715.0

 

 

 

750.0

 

Less: Unamortized discounts and debt issuance costs

 

 

(3.3

)

 

 

(3.7

)

Less: Current portion

 

 

—

 

 

 

(35.0

)

Spire Alabama long-term debt, excluding current portion

 

$

711.7

 

 

$

711.3

 
Schedule of Maturities of Long-Term Debt

Maturities of long-term debt for Spire on a consolidated basis, Spire Missouri and Spire Alabama for the five fiscal years after September 30, 2025 are as follows:

 

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030

 

Spire

 

$

487.5

 

 

$

108.1

 

 

$

53.6

 

 

$

28.5

 

 

$

594.9

 

Spire Missouri

 

 

—

 

 

 

—

 

 

 

45.0

 

 

 

19.3

 

 

 

395.0

 

Spire Alabama

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

190.0

 
v3.25.3
Notes Payable and Credit Agreements (Tables)
 12 Months Ended
Sep. 30, 2025
Debt Disclosure [Abstract]  
Schedule of Short-Term Debt

Information about short-term borrowings, including Spire Missouri’s and Spire Alabama’s borrowings from Spire, is presented in the following table. As of September 30, 2025, $741.0 of Spire’s short-term borrowings were used to support lending to the Utilities.

 

 

 

Spire

 

 

Spire

 

 

Spire

 

 

 

 

 

 

(Parent Only)

 

 

Missouri

 

 

Alabama

 

 

Spire

 

 

 

CP

 

 

 

Spire

 

 

Spire

 

 

Consol-

 

 

 

Program

 

 

 

Note

 

 

Note

 

 

idated

 

Year Ended September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

Highest borrowings outstanding

 

$

1,348.0

 

 

 

$

615.0

 

 

$

130.6

 

 

$

1,348.0

 

Lowest borrowings outstanding

 

 

896.0

 

 

 

 

299.5

 

 

 

1.2

 

 

 

896.0

 

Weighted average borrowings

 

 

1,085.7

 

 

 

 

482.6

 

 

 

50.8

 

 

 

1,085.7

 

Weighted average interest rate

 

 

4.5

%

 

 

 

4.7

%

 

 

4.7

%

 

 

4.5

%

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

Borrowings outstanding

 

$

1,317.0

 

 

 

$

566.3

 

 

$

130.1

 

 

$

1,317.0

 

Weighted average interest rate

 

 

4.4

%

 

 

 

4.4

%

 

 

4.4

%

 

 

4.4

%

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

 

Borrowings outstanding

 

$

947.0

 

 

 

$

495.3

 

 

$

48.4

 

 

$

947.0

 

Weighted average interest rate

 

 

5.2

%

 

 

 

5.2

%

 

 

5.2

%

 

 

5.2

%

 

 

For additional information regarding the pending acquisition of Tennessee natural gas business from Piedmont Natural Gas, see Note 18 – Business Combinations, which is supported by a fully committed bridge financing facility discussed therein.
v3.25.3
Fair Value of Financial Instruments (Tables)
 12 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]  
Schedule of Estimated Fair Value of Financial Instruments Not Measured at Fair Value on Recurring Basis

The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis were as follows:

 

 

 

 

 

 

 

 

 

Classification of

 

 

 

 

 

 

 

 

 

Estimated Fair Value

 

 

 

 

 

 

 

 

 

Quoted

 

 

 

 

 

 

 

 

 

 

 

 

Prices in

 

 

Significant

 

 

 

 

 

 

 

 

 

Active

 

 

Observable

 

 

 

Carrying

 

 

Fair

 

 

Markets

 

 

Inputs

 

 

 

Amount

 

 

Value

 

 

(Level 1)

 

 

(Level 2)

 

Spire

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

5.7

 

 

$

5.7

 

 

$

5.7

 

 

$

—

 

Notes payable

 

 

1,317.0

 

 

 

1,317.0

 

 

 

—

 

 

 

1,317.0

 

Long-term debt, including current portion

 

 

3,856.9

 

 

 

3,691.5

 

 

 

—

 

 

 

3,691.5

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

4.5

 

 

$

4.5

 

 

$

4.5

 

 

$

—

 

Notes payable

 

 

947.0

 

 

 

947.0

 

 

 

—

 

 

 

947.0

 

Long-term debt, including current portion

 

 

3,746.4

 

 

 

3,600.3

 

 

 

—

 

 

 

3,600.3

 

Spire Missouri

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Notes payable - associated companies

 

$

566.3

 

 

$

566.3

 

 

$

—

 

 

$

566.3

 

Long-term debt

 

 

1,953.6

 

 

 

1,874.0

 

 

 

—

 

 

 

1,874.0

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Notes payable - associated companies

 

$

495.3

 

 

$

495.3

 

 

$

—

 

 

$

495.3

 

Long-term debt

 

 

1,803.4

 

 

 

1,736.9

 

 

 

—

 

 

 

1,736.9

 

Spire Alabama

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

1.9

 

 

$

1.9

 

 

$

1.9

 

 

$

—

 

Notes payable - associated companies

 

 

130.1

 

 

 

130.1

 

 

 

—

 

 

 

130.1

 

Long-term debt

 

 

711.7

 

 

 

675.9

 

 

 

—

 

 

 

675.9

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

1.5

 

 

$

1.5

 

 

$

1.5

 

 

$

—

 

Notes payable - associated companies

 

 

48.4

 

 

 

48.4

 

 

 

—

 

 

 

48.4

 

Long-term debt, including current portion

 

 

746.3

 

 

 

711.8

 

 

 

—

 

 

 

711.8

 
v3.25.3
Fair Value Measurements (Tables)
 12 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]  
Schedule of Derivative Assets and Liabilities, Including Receivables and Payables

 

 

 

 

 

 

 

 

 

 

 

Effects of

 

 

 

 

 

 

Quoted

 

 

 

 

 

 

 

 

Netting

 

 

 

 

 

 

Prices

 

 

Significant

 

 

Significant

 

 

and Cash

 

 

 

 

 

 

in Active

 

 

Observable

 

 

Unobservable

 

 

Margin

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

Inputs

 

 

Receivables

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

(Level 3)

 

 

/Payables

 

 

Total

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

27.5

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

27.5

 

NYMEX/ICE natural gas contracts

 

 

2.9

 

 

 

—

 

 

 

—

 

 

 

(2.9

)

 

 

—

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

11.4

 

 

 

—

 

 

 

—

 

 

 

(11.4

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

44.8

 

 

 

—

 

 

 

(2.7

)

 

 

42.1

 

Other:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

 

27.0

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

27.0

 

U.S. bonds

 

 

23.5

 

 

 

—

 

 

 

—

 

 

 

 

 

 

23.5

 

Global Bonds

 

 

1.5

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

1.5

 

Interest rate swaps

 

 

—

 

 

 

10.0

 

 

 

—

 

 

 

—

 

 

 

10.0

 

Total

 

$

93.8

 

 

$

54.8

 

 

$

—

 

 

$

(17.0

)

 

$

131.6

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

25.9

 

 

$

—

 

 

$

—

 

 

$

(1.3

)

 

$

24.6

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

19.0

 

 

 

—

 

 

 

—

 

 

 

(19.0

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

16.7

 

 

 

—

 

 

 

(2.7

)

 

 

14.0

 

Total

 

$

44.9

 

 

$

16.7

 

 

$

—

 

 

$

(23.0

)

 

$

38.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

24.3

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

24.3

 

NYMEX/ICE natural gas contracts

 

 

3.4

 

 

 

—

 

 

 

—

 

 

 

(3.4

)

 

 

—

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

7.0

 

 

 

—

 

 

 

—

 

 

 

(7.0

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

46.0

 

 

 

—

 

 

 

(3.5

)

 

 

42.5

 

Other:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

 

17.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

17.9

 

U.S. bonds

 

 

21.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

21.9

 

Global Bonds

 

 

5.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

5.9

 

Interest rate swaps

 

 

—

 

 

 

0.8

 

 

 

—

 

 

 

—

 

 

 

0.8

 

Total

 

$

80.4

 

 

$

46.8

 

 

$

—

 

 

$

(13.9

)

 

$

113.3

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

13.6

 

 

$

—

 

 

$

—

 

 

$

(3.8

)

 

$

9.8

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

 

17.7

 

 

 

—

 

 

 

—

 

 

 

(17.7

)

 

 

—

 

Natural gas commodity contracts

 

 

—

 

 

 

24.5

 

 

 

—

 

 

 

(3.5

)

 

 

21.0

 

Other:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Interest rate swaps

 

 

—

 

 

 

1.5

 

 

 

—

 

 

 

—

 

 

 

1.5

 

Total

 

$

31.3

 

 

$

26.0

 

 

$

—

 

 

$

(25.0

)

 

$

32.3

 

 

Spire Missouri

 

 

 

 

 

 

 

 

 

 

 

 

Effects of

 

 

 

 

 

 

Quoted

 

 

 

 

 

 

 

 

Netting

 

 

 

 

 

 

Prices

 

 

Significant

 

 

Significant

 

 

and Cash

 

 

 

 

 

 

in Active

 

 

Observable

 

 

Unobservable

 

 

Margin

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

Inputs

 

 

Receivables

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

(Level 3)

 

 

/Payables

 

 

Total

 

As of September 30, 2025

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

27.5

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

27.5

 

NYMEX/ICE natural gas contracts

 

 

2.9

 

 

 

—

 

 

 

—

 

 

 

(2.9

)

 

 

—

 

Total

 

$

30.4

 

 

$

—

 

 

$

—

 

 

$

(2.9

)

 

$

27.5

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

25.9

 

 

$

—

 

 

$

—

 

 

$

(1.3

)

 

$

24.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As of September 30, 2024

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. stock/bond mutual funds

 

$

24.3

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

24.3

 

NYMEX/ICE natural gas contracts

 

 

3.4

 

 

 

—

 

 

 

—

 

 

 

(3.4

)

 

 

—

 

Total

 

$

27.7

 

 

$

—

 

 

$

—

 

 

$

(3.4

)

 

$

24.3

 

LIABILITIES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NYMEX/ICE natural gas contracts

 

$

13.6

 

 

$

—

 

 

$

—

 

 

$

(3.8

)

 

$

9.8

 
v3.25.3
Derivative Instruments and Hedging Activities (Tables)
 12 Months Ended
Sep. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]  
Schedule of Derivative Instruments

 

 

September 30, 2025

 

 

September 30, 2024

 

Gas Marketing

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

Natural gas futures purchased

 

 

48.0

 

 

 

48

 

 

 

56.0

 

 

 

48

 

Natural gas options purchased, net

 

 

9.9

 

 

 

15

 

 

 

3.8

 

 

 

15

 

Natural gas basis swaps purchased

 

 

24.7

 

 

 

39

 

 

 

32.4

 

 

 

39

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Utility

 

 

 

 

 

 

 

 

 

 

 

 

Natural gas futures purchased

 

 

32.3

 

 

 

12.0

 

 

 

34.6

 

 

 

12

 

 

 

September 30, 2025

 

 

September 30, 2024

 

 

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

 

Notional
(MMBtu
millions)

 

 

Maximum
Term
(Months)

 

Natural gas futures purchased

 

 

32.3

 

 

 

12

 

 

 

34.6

 

 

 

12

 
Derivative Instruments, Gain (Loss)

Effect of Derivative Instruments on the Consolidated Statements of Income and Comprehensive Income

 

 

 

Location of Gain (Loss)

 

 

 

 

 

 

 

 

 

 

 

Recorded in Income

 

2025

 

 

2024

 

 

2023

 

Derivatives in Cash Flow Hedging Relationships

 

 

 

 

 

 

 

 

 

Portion of gain (loss) recognized in OCI on derivatives:

 

 

 

 

 

 

 

 

 

Interest rate swaps

 

 

 

$

12.8

 

 

$

(15.9

)

 

$

20.1

 

Portion of gain reclassified from AOCI to income:

 

 

 

 

 

 

 

 

 

Interest rate swaps

 

Interest Expense

 

$

5.1

 

 

$

11.1

 

 

$

2.4

 

 

 

 

 

 

 

 

 

 

 

 

Derivatives Not Designated as Hedging Instruments*

 

 

 

 

 

 

 

 

 

(Loss) gain recognized in income on derivatives:

 

 

 

 

 

 

 

 

 

Gas / diesel futures

 

Other Income (Expense), Net

 

$

—

 

 

$

(0.3

)

 

$

0.3

 

Natural gas commodity contracts

 

Operating Expenses: Natural Gas

 

 

(6.5

)

 

 

12.5

 

 

 

18.0

 

NYMEX / ICE natural gas contracts

 

Operating Expenses: Natural Gas

 

 

(3.1

)

 

 

(16.3

)

 

 

(35.0

)

Total

 

 

 

$

(9.6

)

 

$

(4.1

)

 

$

(16.7

)
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value

Fair Value of Derivative Instruments in the Consolidated Balance Sheets

 

 

 

Derivative Assets*

 

 

Derivative Liabilities*

 

September 30, 2025

 

Balance Sheet Location

 

Fair
Value

 

 

Balance Sheet Location

 

Fair
Value

 

Derivatives designated as hedging instruments

 

 

 

 

 

 

 

 

Other: Interest rate swaps

 

Current Assets: Other

 

$

10.0

 

 

Current Liabilities: Other

 

$

—

 

Subtotal

 

 

 

 

10.0

 

 

 

 

 

—

 

 

 

 

 

 

 

 

 

 

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

 

2.9

 

 

Current Liabilities: Other

 

 

25.9

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

NYMEX / ICE natural gas contracts

 

Current Assets: Other

 

 

11.3

 

 

Current Liabilities: Other

 

 

17.7

 

 

Deferred Charges and Other Assets: Other

 

 

0.1

 

 

Deferred Credits and Other Liabilities: Other

 

 

1.3

 

Natural gas commodity

 

Current Assets: Other

 

 

42.8

 

 

Current Liabilities: Other

 

 

15.6

 

 

Deferred Charges and Other Assets: Other

 

 

2.0

 

 

Deferred Credits and Other Liabilities: Other

 

 

1.1

 

Subtotal

 

 

 

 

59.1

 

 

 

 

 

61.6

 

Total derivatives

 

 

 

$

69.1

 

 

 

 

$

61.6

 

 

 

 

 

 

 

 

 

 

 

September 30, 2024

 

 

 

 

 

 

 

 

 

 

Derivatives designated as hedging instruments

 

 

 

 

 

 

 

 

Other: Interest rate swaps

 

Current Assets: Other

 

$

0.8

 

 

Current Liabilities: Other

 

$

1.5

 

Subtotal

 

 

 

 

0.8

 

 

 

 

 

1.5

 

 

 

 

 

 

 

 

 

 

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Gas Utility:

 

 

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

 

3.4

 

 

Current Liabilities: Other

 

 

13.6

 

Gasoline and heating oil contracts

 

Current Assets: Other

 

 

—

 

 

 

 

 

—

 

Gas Marketing:

 

 

 

 

 

 

 

 

 

 

NYMEX / ICE natural gas contracts

 

Current Assets: Other

 

 

6.2

 

 

Current Liabilities: Other

 

 

13.7

 

 

Deferred Charges and Other Assets: Other

 

 

0.8

 

 

Deferred Credits and Other Liabilities: Other

 

 

4.0

 

Natural gas commodity

 

Current Assets: Other

 

 

42.1

 

 

Current Liabilities: Other

 

 

19.8

 

 

Deferred Charges and Other Assets: Other

 

 

3.9

 

 

Deferred Credits and Other Liabilities: Other

 

 

4.7

 

Subtotal

 

 

 

 

56.4

 

 

 

 

 

55.8

 

Total derivatives

 

 

 

$

57.2

 

 

 

 

$

57.3

 

 

 

* The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of the Company’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.

Fair Value of Derivative Instruments in the Balance Sheets

 

 

 

Derivative Assets*

 

 

Derivative Liabilities*

 

September 30, 2025

 

Balance Sheet Location

 

Fair
Value

 

 

Balance Sheet Location

 

Fair
Value

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

$

2.9

 

 

Current Liabilities: Other

 

$

25.9

 

Total derivatives

 

 

 

$

2.9

 

 

 

 

$

25.9

 

 

 

 

 

 

 

 

 

 

 

September 30, 2024

 

 

 

 

 

 

 

 

 

 

Derivatives not designated as hedging instruments

 

 

 

 

 

 

 

 

Natural gas contracts

 

Current Assets: Other

 

$

3.4

 

 

Current Liabilities: Other

 

$

13.6

 

Gasoline and heating oil contracts

 

Current Assets: Other

 

 

—

 

 

 

 

 

—

 

Total derivatives

 

 

 

$

3.4

 

 

 

 

$

13.6

 

* The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of Spire Missouri’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.
Derivative Instrument Reconciliation

 

 

2025

 

 

2024

 

Fair value of derivative assets presented above

 

$

69.1

 

 

$

57.2

 

Fair value of cash margin receivable offset with derivatives

 

 

6.0

 

 

 

11.1

 

Netting of assets and liabilities with the same counterparty

 

 

(23.0

)

 

 

(25.0

)

Total

 

$

52.1

 

 

$

43.3

 

Derivative Instrument Assets, per Consolidated Balance Sheets:

 

 

 

 

 

 

Current Assets: Other

 

$

50.1

 

 

$

39.5

 

Deferred Charges and Other Assets: Other

 

 

2.0

 

 

 

3.8

 

Total

 

$

52.1

 

 

$

43.3

 

 

 

 

 

 

 

Fair value of derivative liabilities presented above

 

$

61.6

 

 

$

57.3

 

Netting of assets and liabilities with the same counterparty

 

 

(23.0

)

 

 

(25.0

)

Total

 

$

38.6

 

 

$

32.3

 

Derivative Instrument Liabilities, per Consolidated Balance Sheets:

 

 

 

 

 

 

Current Liabilities: Other

 

$

37.5

 

 

$

27.6

 

Deferred Credits and Other Liabilities: Other

 

 

1.1

 

 

 

4.7

 

Total

 

$

38.6

 

 

$

32.3

 

 

 

2025

 

 

2024

 

Fair value of derivative assets presented above

 

$

2.9

 

 

$

3.4

 

Fair value of cash margin receivable offset with derivatives

 

 

(1.6

)

 

 

0.4

 

Netting of assets and liabilities with the same counterparty

 

 

(1.3

)

 

 

(3.8

)

Total

 

$

—

 

 

$

—

 

 

 

 

 

 

 

Fair value of derivative liabilities presented above

 

$

25.9

 

 

$

13.6

 

Netting of assets and liabilities with the same counterparty

 

 

(1.3

)

 

 

(3.8

)

Total

 

 

24.6

 

 

 

9.8

 

 

 

 

 

 

 

Derivative Instrument Liabilities, per Balance Sheets:

 

 

 

 

 

 

Current Liabilities: Other

 

$

24.6

 

 

$

9.8

 

Deferred Credits and Other Liabilities: Other

 

 

-

 

 

 

—

 

Total

 

$

24.6

 

 

$

9.8

 
Interest Rate Swap [Member]  
Derivative Instruments and Hedging Activities Disclosures [Line Items]  
Schedule of Derivative Instruments

Period Originated

 

Contract
Hedge Term
(Years)

 

 

Notional
Amount

 

 

Fixed
Interest
Rate

 

 

Fiscal 2025
Mark-to-
Market Gain

 

Quarter 3, fiscal 2023

 

 

10

 

 

$

25.0

 

 

 

3.018

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.400

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.525

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.535

%

 

 

0.8

 

Quarter 1, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.450

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.541

%

 

 

0.7

 

Quarter 4, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.552

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

 

10

 

 

 

25.0

 

 

 

3.426

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.577

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.450

%

 

 

0.8

 

Quarter 4, fiscal 2024

 

10

 

 

 

25.0

 

 

 

3.350

%

 

 

0.8

 

Quarter 1, fiscal 2025

 

1.5

 

 

 

125.0

 

 

 

3.567

%

 

 

0.2

 

Quarter 1, fiscal 2025

 

1.5

 

 

 

225.0

 

 

 

3.567

%

 

 

0.4

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.580

%

 

 

0.3

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.611

%

 

 

0.3

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.657

%

 

 

0.3

 

Quarter 3, fiscal 2025

 

10

 

 

 

25.0

 

 

 

3.763

%

 

 

0.5

 

 

 

 

 

$

725.0

 

 

 

 

 

$

10.7

 
v3.25.3
Income Taxes (Tables)
 12 Months Ended
Sep. 30, 2025
Income Tax Disclosure [Abstract]  
Provision for Income Taxes

The provision for income taxes during the fiscal years ended September 30, 2025, 2024, and 2023 was as follows:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Federal:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

1.7

 

 

$

0.2

 

 

$

0.7

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

Deferred

 

 

46.3

 

 

 

46.1

 

 

 

30.4

 

 

 

12.4

 

 

 

13.5

 

 

 

10.1

 

 

 

22.9

 

 

 

21.7

 

 

 

15.8

 

Investment tax credits

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

(0.2

)

 

 

—

 

 

 

—

 

 

 

—

 

State and local:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

 

0.7

 

 

 

1.5

 

 

 

1.2

 

 

 

0.2

 

 

 

0.9

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Deferred

 

 

11.2

 

 

 

11.1

 

 

 

6.7

 

 

 

1.4

 

 

 

1.5

 

 

 

1.7

 

 

 

5.5

 

 

 

5.2

 

 

 

4.5

 

Total income tax expense

 

$

59.7

 

 

$

58.7

 

 

$

38.8

 

 

$

13.8

 

 

$

15.7

 

 

$

11.6

 

 

$

28.4

 

 

$

26.9

 

 

$

20.3

 
Effective Income Tax Rate

The effective income tax rate varied from the federal statutory income tax rate for each year due to the following:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Federal income tax statutory rate

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

 

 

21.0

 %

State and local income taxes, net of federal
   income tax benefits

 

 

3.7

 

 

 

3.7

 

 

 

3.7

 

 

 

2.6

 

 

 

2.6

 

 

 

2.6

 

 

 

4.1

 

 

 

4.1

 

 

 

4.1

 

Certain expenses capitalized on books and
   deducted on tax return

 

 

(1.1

)

 

 

(1.2

)

 

 

(1.4

)

 

 

(2.5

)

 

 

(2.7

)

 

 

(2.7

)

 

 

—

 

 

 

—

 

 

 

—

 

Tax credits *

 

 

(0.8

)

 

 

(0.9

)

 

 

(3.3

)

 

 

(1.1

)

 

 

(1.1

)

 

 

(4.2

)

 

 

(0.3

)

 

 

(0.3

)

 

 

(1.9

)

Amortization of excess deferred taxes

 

 

(3.1

)

 

 

(3.3

)

 

 

(5.1

)

 

 

(7.0

)

 

 

(7.4

)

 

 

(7.7

)

 

 

0.1

 

 

 

0.2

 

 

 

0.2

 

Taxes related to prior years

 

 

(1.3

)

 

 

—

 

 

 

—

 

 

 

(2.9

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Other items – net

 

 

(0.4

)

 

 

(0.3

)

 

 

0.2

 

 

 

(0.4

)

 

 

(0.7

)

 

 

—

 

 

 

0.1

 

 

 

0.1

 

 

 

0.1

 

Effective income tax rate

 

 

18.0

 %

 

 

19.0

 %

 

 

15.1

 %

 

 

9.7

 %

 

 

11.7

 %

 

 

9.0

 %

 

 

25.0

 %

 

 

25.1

 %

 

 

23.5

 %

 

* In 2023, the Company completed a research and development study which encompassed fiscal years 2014 to 2022.
Significant Items Comprising the Net Deferred Tax Liability or Asset

The significant items comprising the net deferred tax liability or asset as of September 30 were as follows:

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Deferred tax assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Operating losses

 

$

150.1

 

 

$

182.2

 

 

$

1.5

 

 

$

24.7

 

 

$

146.1

 

 

$

153.0

 

Goodwill

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

29.7

 

 

 

44.4

 

Pension and other postretirement benefits

 

 

52.6

 

 

 

58.6

 

 

 

36.0

 

 

 

39.3

 

 

 

14.8

 

 

 

17.1

 

Regulatory amount due to customers, net

 

 

23.9

 

 

 

27.1

 

 

 

21.4

 

 

 

24.5

 

 

 

—

 

 

 

2.3

 

Reserves not currently deductible

 

 

24.9

 

 

 

0.5

 

 

 

—

 

 

 

—

 

 

 

3.4

 

 

 

2.9

 

Other

 

 

73.5

 

 

 

43.3

 

 

 

16.7

 

 

 

12.3

 

 

 

6.0

 

 

 

2.1

 

Total deferred tax assets

 

 

325.0

 

 

 

311.7

 

 

 

75.6

 

 

 

100.8

 

 

 

200.0

 

 

 

221.8

 

Deferred tax liabilities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Relating to property

 

 

(912.3

)

 

 

(842.2

)

 

 

(572.6

)

 

 

(531.2

)

 

 

(238.1

)

 

 

(230.0

)

Regulatory pension and other postretirement
   benefits

 

 

(54.4

)

 

 

(60.8

)

 

 

(27.2

)

 

 

(33.8

)

 

 

(24.0

)

 

 

(25.6

)

Deferred gas costs

 

 

(10.7

)

 

 

(19.9

)

 

 

(8.2

)

 

 

(17.7

)

 

 

—

 

 

 

—

 

Other ***

 

 

(235.0

)

 

 

(197.2

)

 

 

(66.3

)

 

 

(85.7

)

 

 

(2.0

)

 

 

(2.1

)

Total deferred tax liabilities

 

 

(1,212.4

)

 

 

(1,120.1

)

 

 

(674.3

)

 

 

(668.4

)

 

 

(264.1

)

 

 

(257.7

)

Net deferred tax (liability) asset

 

$

(887.4

)

 

$

(808.4

)

 

$

(598.7

)

 

$

(567.6

)

 

$

(64.1

)

 

$

(35.9

)

 

*** For Spire, Other consists primarily of goodwill-related liabilities.
Summary of Federal and State Loss and Contribution and Tax Credit Carryforwards

 

 

Spire

 

 

Spire
Missouri

 

 

Spire
Alabama

 

Federal and state loss carryforwards

 

$

646.1

 

 

$

9.7

 

 

$

583.3

 

Tax credit carryforwards

 

 

18.9

 

 

 

8.8

 

 

 

2.7

 
Schedule of Unrecognized Tax Benefits Roll Forward

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Unrecognized tax benefits, beginning of year

 

$

26.3

 

 

$

23.8

 

 

$

19.6

 

 

$

25.3

 

 

$

22.9

 

 

$

19.3

 

 

$

0.3

 

 

$

0.3

 

 

$

—

 

Increases related to tax positions taken in
   current year

 

 

0.6

 

 

 

2.6

 

 

 

4.2

 

 

 

0.2

 

 

 

2.4

 

 

 

3.6

 

 

 

—

 

 

 

—

 

 

 

0.3

 

Decreases related to tax positions taken in prior years

 

 

(24.2

)

 

 

—

 

 

 

—

 

 

 

(24.2

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Reductions due to lapse of applicable statute
   of limitations

 

 

—

 

 

 

(0.1

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Unrecognized tax benefits, end of year

 

$

2.7

 

 

$

26.3

 

 

$

23.8

 

 

$

1.3

 

 

$

25.3

 

 

$

22.9

 

 

$

0.3

 

 

$

0.3

 

 

$

0.3

 
v3.25.3
Pension Plans and Other Postretirement Benefits (Tables)
 12 Months Ended
Sep. 30, 2025
Retirement Benefits [Abstract]  
Schedule of Net Benefit Costs

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Service cost – benefits earned during
   the period

 

$

17.6

 

 

$

15.7

 

 

$

16.3

 

 

$

11.4

 

 

$

10.4

 

 

$

11.4

 

 

$

5.5

 

 

$

4.6

 

 

$

4.2

 

Interest cost on projected benefit
   obligation

 

 

23.5

 

 

 

26.7

 

 

 

25.1

 

 

 

15.8

 

 

 

18.9

 

 

 

17.8

 

 

 

5.1

 

 

 

5.1

 

 

 

4.8

 

Expected return on plan assets

 

 

(25.9

)

 

 

(24.8

)

 

 

(24.5

)

 

 

(17.6

)

 

 

(17.0

)

 

 

(18.0

)

 

 

(5.3

)

 

 

(4.8

)

 

 

(3.5

)

Amortization of prior service credit

 

 

(4.5

)

 

 

(4.5

)

 

 

(4.5

)

 

 

(1.9

)

 

 

(1.9

)

 

 

(1.9

)

 

 

(2.4

)

 

 

(2.4

)

 

 

(2.4

)

Amortization of actuarial loss

 

 

6.5

 

 

 

6.4

 

 

 

6.6

 

 

 

4.1

 

 

 

5.9

 

 

 

6.1

 

 

 

2.4

 

 

 

1.0

 

 

 

0.9

 

Special termination benefits

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Loss on lump-sum settlements and
   curtailments

 

 

0.4

 

 

 

12.9

 

 

 

9.7

 

 

 

0.4

 

 

 

12.9

 

 

 

0.6

 

 

 

—

 

 

 

—

 

 

 

9.1

 

Subtotal

 

 

17.6

 

 

 

35.0

 

 

 

28.7

 

 

 

12.2

 

 

 

31.8

 

 

 

16.0

 

 

 

5.3

 

 

 

3.5

 

 

 

13.1

 

Regulatory adjustment

 

 

36.3

 

 

 

18.4

 

 

 

26.3

 

 

 

29.6

 

 

 

10.8

 

 

 

27.1

 

 

 

5.8

 

 

 

6.7

 

 

 

(1.7

)

Net pension cost

 

$

53.9

 

 

$

53.4

 

 

$

55.0

 

 

$

41.8

 

 

$

42.6

 

 

$

43.1

 

 

$

11.1

 

 

$

10.2

 

 

$

11.4

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Service cost – benefits earned during
   the period

 

$

4.2

 

 

$

4.3

 

 

$

4.8

 

 

$

3.5

 

 

$

3.5

 

 

$

4.0

 

 

$

0.7

 

 

$

0.7

 

 

$

0.7

 

Interest cost on accumulated
   postretirement benefit obligation

 

 

7.3

 

 

 

8.9

 

 

 

8.5

 

 

 

5.2

 

 

 

6.6

 

 

 

6.5

 

 

 

2.0

 

 

 

2.1

 

 

 

1.8

 

Expected return on plan assets

 

 

(16.9

)

 

 

(16.0

)

 

 

(15.8

)

 

 

(11.1

)

 

 

(10.6

)

 

 

(10.5

)

 

 

(5.4

)

 

 

(5.1

)

 

 

(5.0

)

Amortization of prior service cost
   (credit)

 

 

0.2

 

 

 

0.3

 

 

 

0.3

 

 

 

0.3

 

 

 

0.6

 

 

 

0.6

 

 

 

(0.1

)

 

 

(0.3

)

 

 

(0.3

)

Amortization of actuarial gain

 

 

(5.8

)

 

 

(5.8

)

 

 

(4.0

)

 

 

(5.1

)

 

 

(5.2

)

 

 

(3.2

)

 

 

(0.1

)

 

 

(0.1

)

 

 

(0.5

)

Special termination benefits

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Subtotal

 

 

(11.0

)

 

 

(2.2

)

 

 

(6.2

)

 

 

(7.2

)

 

 

1.0

 

 

 

(2.6

)

 

 

(2.9

)

 

 

(2.7

)

 

 

(3.3

)

Regulatory adjustment

 

 

4.5

 

 

 

(3.6

)

 

 

0.6

 

 

 

6.2

 

 

 

(1.9

)

 

 

1.8

 

 

 

(1.8

)

 

 

(1.8

)

 

 

(1.3

)

Net postretirement benefit income

 

$

(6.5

)

 

$

(5.8

)

 

$

(5.6

)

 

$

(1.0

)

 

$

(0.9

)

 

$

(0.8

)

 

$

(4.7

)

 

$

(4.5

)

 

$

(4.6

)
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Current year actuarial (gain) loss

 

$

(11.9

)

 

$

8.8

 

 

$

14.5

 

 

$

(9.9

)

 

$

(0.9

)

 

$

5.7

 

 

$

(0.8

)

 

$

8.5

 

 

$

9.0

 

Amortization of actuarial loss

 

 

(6.5

)

 

 

(6.4

)

 

 

(6.6

)

 

 

(4.1

)

 

 

(5.9

)

 

 

(6.1

)

 

 

(2.4

)

 

 

(1.0

)

 

 

(0.9

)

Acceleration of loss recognized due to
   settlement

 

 

(0.4

)

 

 

(12.9

)

 

 

(9.7

)

 

 

(0.4

)

 

 

(12.9

)

 

 

(0.6

)

 

 

—

 

 

 

—

 

 

 

(9.1

)

Current year service credit

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Amortization of prior service credit

 

 

4.5

 

 

 

4.5

 

 

 

4.5

 

 

 

1.9

 

 

 

1.9

 

 

 

1.9

 

 

 

2.4

 

 

 

2.4

 

 

 

2.4

 

Subtotal

 

 

(14.3

)

 

 

(5.8

)

 

 

2.7

 

 

 

(12.5

)

 

 

(17.6

)

 

 

0.9

 

 

 

(0.8

)

 

 

9.9

 

 

 

1.4

 

Regulatory adjustment

 

 

13.0

 

 

 

5.2

 

 

 

(2.8

)

 

 

11.2

 

 

 

17.0

 

 

 

(1.0

)

 

 

0.8

 

 

 

(9.9

)

 

 

(1.4

)

Total recognized in OCI

 

$

(1.3

)

 

$

(0.6

)

 

$

(0.1

)

 

$

(1.3

)

 

$

(0.6

)

 

$

(0.1

)

 

$

—

 

 

$

—

 

 

$

—

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Current year actuarial (gain) loss

 

$

(36.5

)

 

$

(52.4

)

 

$

(24.4

)

 

$

(31.9

)

 

$

(40.4

)

 

$

(21.5

)

 

$

(4.0

)

 

$

(9.3

)

 

$

(1.1

)

Amortization of actuarial gain

 

 

5.8

 

 

 

5.8

 

 

 

4.0

 

 

 

5.1

 

 

 

5.2

 

 

 

3.2

 

 

 

0.1

 

 

 

0.1

 

 

 

0.5

 

Current year prior service cost

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Amortization of prior service (cost)
   credit

 

 

(0.2

)

 

 

(0.3

)

 

 

(0.3

)

 

 

(0.3

)

 

 

(0.6

)

 

 

(0.6

)

 

 

0.1

 

 

 

0.3

 

 

 

0.3

 

Subtotal

 

 

(30.9

)

 

 

(51.6

)

 

 

(20.7

)

 

 

(27.1

)

 

 

(40.5

)

 

 

(18.9

)

 

 

(3.8

)

 

 

(8.9

)

 

 

(0.3

)

Regulatory adjustment

 

 

30.9

 

 

 

51.6

 

 

 

20.7

 

 

 

27.1

 

 

 

40.5

 

 

 

18.9

 

 

 

3.8

 

 

 

8.9

 

 

 

0.3

 

Total recognized in OCI

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 
Schedule of Accumulated and Projected Benefit Obligations

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Benefit obligation, beginning of year

 

$

469.7

 

 

$

438.7

 

 

$

319.7

 

 

$

313.2

 

 

$

97.9

 

 

$

80.6

 

Service cost

 

 

17.6

 

 

 

15.7

 

 

 

11.4

 

 

 

10.4

 

 

 

5.5

 

 

 

4.6

 

Interest cost

 

 

23.5

 

 

 

26.7

 

 

 

15.8

 

 

 

18.9

 

 

 

5.1

 

 

 

5.1

 

Actuarial loss (gain)

 

 

(15.3

)

 

 

46.0

 

 

 

(8.5

)

 

 

25.2

 

 

 

(4.3

)

 

 

14.3

 

Plan amendments

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

Special termination benefits

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

2.6

 

 

 

—

 

 

 

—

 

Settlement benefits paid

 

 

(1.5

)

 

 

(37.3

)

 

 

(1.5

)

 

 

(37.3

)

 

 

—

 

 

 

—

 

Regular benefits paid

 

 

(43.8

)

 

 

(22.9

)

 

 

(29.7

)

 

 

(13.5

)

 

 

(11.2

)

 

 

(6.7

)

Benefit obligation, end of year

 

$

450.2

 

 

$

469.7

 

 

$

307.2

 

 

$

319.7

 

 

$

93.0

 

 

$

97.9

 

Accumulated benefit obligation, end of year

 

$

439.6

 

 

$

459.4

 

 

$

302.8

 

 

$

314.7

 

 

$

87.3

 

 

$

92.9

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Benefit obligation, beginning of year

 

$

142.5

 

 

$

142.6

 

 

$

102.4

 

 

$

105.3

 

 

$

39.0

 

 

$

35.1

 

Service cost

 

 

4.2

 

 

 

4.3

 

 

 

3.5

 

 

 

3.5

 

 

 

0.7

 

 

 

0.7

 

Interest cost

 

 

7.3

 

 

 

8.9

 

 

 

5.2

 

 

 

6.6

 

 

 

2.0

 

 

 

2.1

 

Actuarial (gain) loss

 

 

(18.4

)

 

 

(1.5

)

 

 

(17.1

)

 

 

(3.2

)

 

 

(1.2

)

 

 

3.1

 

Plan amendments

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

(4.7

)

 

 

—

 

 

 

—

 

Retiree drug subsidy program

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

0.2

 

 

 

—

 

 

 

—

 

Special termination benefits

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

6.1

 

 

 

—

 

 

 

—

 

Benefits paid

 

 

(4.1

)

 

 

(13.4

)

 

 

(1.9

)

 

 

(11.4

)

 

 

(2.2

)

 

 

(2.0

)

Benefit obligation, end of year

 

$

131.5

 

 

$

142.5

 

 

$

92.1

 

 

$

102.4

 

 

$

38.3

 

 

$

39.0

 
Schedule of Changes in Fair Value of Plan Assets

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Fair value of plan assets, beginning of year

 

$

374.8

 

 

$

334.7

 

 

$

259.8

 

 

$

242.0

 

 

$

69.9

 

 

$

53.6

 

Actual return on plan assets

 

 

22.4

 

 

 

61.8

 

 

 

19.0

 

 

 

43.2

 

 

 

1.8

 

 

 

10.4

 

Employer contributions

 

 

75.8

 

 

 

38.5

 

 

 

37.2

 

 

 

25.4

 

 

 

30.1

 

 

 

12.6

 

Settlement benefits paid

 

 

(1.5

)

 

 

(37.3

)

 

 

(1.5

)

 

 

(37.3

)

 

 

—

 

 

 

—

 

Regular benefits paid

 

 

(43.8

)

 

 

(22.9

)

 

 

(29.7

)

 

 

(13.5

)

 

 

(11.2

)

 

 

(6.7

)

Fair value of plan assets, end of year

 

$

427.7

 

 

$

374.8

 

 

$

284.8

 

 

$

259.8

 

 

$

90.6

 

 

$

69.9

 

Funded status of plans, end of year

 

$

(22.5

)

 

$

(94.9

)

 

$

(22.4

)

 

$

(59.9

)

 

$

(2.4

)

 

$

(28.0

)

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Fair value of plan assets at beginning of year

 

$

339.4

 

 

$

286.3

 

 

$

224.9

 

 

$

188.8

 

 

$

107.5

 

 

$

92.0

 

Actual return on plan assets

 

 

34.9

 

 

 

66.3

 

 

 

25.7

 

 

 

47.3

 

 

 

8.2

 

 

 

17.5

 

Employer contributions

 

 

2.7

 

 

 

0.2

 

 

 

2.7

 

 

 

0.2

 

 

 

—

 

 

 

—

 

Benefits paid

 

 

(4.1

)

 

 

(13.4

)

 

 

(1.9

)

 

 

(11.4

)

 

 

(2.2

)

 

 

(2.0

)

Fair value of plan assets, end of year

 

$

372.9

 

 

$

339.4

 

 

$

251.4

 

 

$

224.9

 

 

$

113.5

 

 

$

107.5

 

Funded status of plans, end of year

 

$

241.4

 

 

$

196.9

 

 

$

159.3

 

 

$

122.5

 

 

$

75.2

 

 

$

68.5

 
Schedule of Amounts Recognized in Balance Sheet

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Noncurrent assets

 

$

6.2

 

 

$

—

 

 

$

3.9

 

 

$

—

 

 

$

—

 

 

$

—

 

Current liabilities

 

 

(0.6

)

 

 

(1.0

)

 

 

(0.6

)

 

 

(1.0

)

 

 

—

 

 

 

—

 

Noncurrent liabilities

 

 

(28.1

)

 

 

(93.9

)

 

 

(25.7

)

 

 

(58.9

)

 

 

(2.4

)

 

 

(28.0

)

Total

 

$

(22.5

)

 

$

(94.9

)

 

$

(22.4

)

 

$

(59.9

)

 

$

(2.4

)

 

$

(28.0

)

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Noncurrent assets

 

$

288.2

 

 

$

248.3

 

 

$

206.1

 

 

$

173.9

 

 

$

75.2

 

 

$

68.5

 

Current liabilities

 

 

(0.4

)

 

 

(0.4

)

 

 

(0.4

)

 

 

(0.4

)

 

 

—

 

 

 

—

 

Noncurrent liabilities

 

 

(46.4

)

 

 

(51.0

)

 

 

(46.4

)

 

 

(51.0

)

 

 

—

 

 

 

—

 

Total

 

$

241.4

 

 

$

196.9

 

 

$

159.3

 

 

$

122.5

 

 

$

75.2

 

 

$

68.5

 
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Net actuarial loss

 

$

100.9

 

 

$

119.7

 

 

$

58.5

 

 

$

72.9

 

 

$

44.5

 

 

$

47.7

 

Prior service credit

 

 

(22.0

)

 

 

(26.4

)

 

 

(12.1

)

 

 

(14.0

)

 

 

(9.1

)

 

 

(11.5

)

Subtotal

 

 

78.9

 

 

 

93.3

 

 

 

46.4

 

 

 

58.9

 

 

 

35.4

 

 

 

36.2

 

Adjustments for amounts included in regulatory
   assets

 

 

(77.8

)

 

 

(90.8

)

 

 

(45.3

)

 

 

(56.4

)

 

 

(35.4

)

 

 

(36.2

)

Total

 

$

1.1

 

 

$

2.5

 

 

$

1.1

 

 

$

2.5

 

 

$

—

 

 

$

—

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Net actuarial gain

 

$

(180.6

)

 

$

(150.0

)

 

$

(154.2

)

 

$

(127.5

)

 

$

(19.3

)

 

$

(15.4

)

Prior service cost (credit)

 

 

2.0

 

 

 

2.0

 

 

 

2.0

 

 

 

2.1

 

 

 

—

 

 

 

(0.1

)

Subtotal

 

 

(178.6

)

 

 

(148.0

)

 

 

(152.2

)

 

 

(125.4

)

 

 

(19.3

)

 

 

(15.5

)

Adjustments for amounts included in regulatory
   assets

 

 

178.6

 

 

 

148.0

 

 

 

152.2

 

 

 

125.4

 

 

 

19.3

 

 

 

15.5

 

Total

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 

 

$

—

 
Defined Benefit Plan, Assumptions

 

 

2025

 

2024

 

2023

Weighted average discount rate - Spire Missouri East plan

 

5.10%

 

6.25%

 

5.70%

Weighted average discount rate - Spire Missouri West plan

 

5.05%

 

6.30%

 

5.80%

Weighted average rate of future compensation increase

 

3.50%

 

3.00%

 

3.00%

Expected long-term rate of return on plan assets

 

6.50%

 

6.50%

 

6.50%

 

 

2025

 

2024

 

2023

Weighted average discount rate

 

5.10%

 

6.20%/6.25%

 

5.65%/5.70%

Weighted average rate of future compensation increase

 

3.50%

 

3.00%

 

3.00%

Expected long-term rate of return on plan assets

 

6.75%

 

6.75%

 

6.50%

 

 

2025

 

2024

Weighted average discount rate - Spire Missouri East plan

 

5.55%

 

5.10%

Weighted average discount rate - Spire Missouri West plan

 

5.45%

 

5.05%

Weighted average discount rate - Spire Alabama plans

 

5.55%

 

5.10%

Weighted average rate of future compensation increase (all plans)

 

3.50%

 

3.50%

Cash balance interest crediting rate - Spire Alabama / Spire Missouri

 

4.25%

 

4.25%

 

 

2025

 

2024

 

2023

Weighted average discount rate – Spire Missouri plans

 

5.05%

 

6.30%

 

5.80%

Expected long-term rate of return on plan assets – Spire Missouri plans

 

5.50%

 

5.50%

 

5.50%

 

 

2025

 

2024

 

2023

Weighted average discount rate

 

5.05%

 

6.30%

 

5.80%

Expected long-term rate of return on plan assets

 

4.75%/6.00%

 

4.75%/6.00%

 

4.75%/6.00%
Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Projected benefit obligation

 

$

450.2

 

 

$

469.7

 

 

$

307.2

 

 

$

319.7

 

 

$

93.0

 

 

$

97.9

 

Accumulated benefit obligation

 

 

439.6

 

 

 

459.4

 

 

 

302.8

 

 

 

314.7

 

 

 

87.3

 

 

 

92.9

 

Fair value of plan assets

 

 

427.7

 

 

 

374.8

 

 

 

284.8

 

 

 

259.8

 

 

 

90.6

 

 

 

69.9

 
Schedule of Allocation of Plan Assets

Spire Missouri

 

2025
Target

 

 

2025
Actual

 

 

2024
Target

 

 

2024
Actual

 

Return seeking assets

 

 

70.0

%

 

 

56.6

%

 

 

70.0

%

 

 

71.3

%

Liability hedging assets

 

 

30.0

%

 

 

40.4

%

 

 

30.0

%

 

 

24.3

%

Cash and cash equivalents

 

 

—

%

 

 

3.0

%

 

 

—

%

 

 

4.4

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

Spire Alabama

 

2025
Target

 

 

2025
Actual

 

 

2024
Target

 

 

2024
Actual

 

Return seeking assets

 

 

75.0

%

 

 

72.0

%

 

 

75.0

%

 

 

74.9

%

Liability hedging assets

 

 

25.0

%

 

 

16.8

%

 

 

25.0

%

 

 

22.6

%

Cash and cash equivalents

 

 

—

%

 

 

11.2

%

 

 

—

%

 

 

2.5

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

Spire Missouri

 

Target

 

 

2025
Actual

 

 

2024
Actual

 

Equity securities

 

 

60.0

%

 

 

58.6

%

 

 

60.8

%

Debt securities

 

 

40.0

%

 

 

36.0

%

 

 

38.2

%

Cash and cash equivalents

 

 

—

%

 

 

5.4

%

 

 

1.0

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%

 

Spire Alabama

 

Target

 

 

2025
Actual

 

 

2024
Actual

 

Equity securities

 

 

60.5

%

 

 

60.9

%

 

 

60.7

%

Debt securities

 

 

39.5

%

 

 

39.1

%

 

 

39.3

%

Total

 

 

100.0

%

 

 

100.0

%

 

 

100.0

%
Schedule of Expected Benefit Payments

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030

 

 

2031 –
2035

 

Spire

 

$

51.2

 

 

$

46.0

 

 

$

45.3

 

 

$

42.9

 

 

$

41.7

 

 

$

196.2

 

Spire Missouri

 

 

38.5

 

 

 

33.4

 

 

 

32.6

 

 

 

30.5

 

 

 

29.1

 

 

 

133.5

 

Spire Alabama

 

 

8.8

 

 

 

8.8

 

 

 

8.5

 

 

 

8.4

 

 

 

8.5

 

 

 

42.8

 

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030

 

 

2031 –
2035

 

Spire

 

$

13.4

 

 

$

13.0

 

 

$

12.5

 

 

$

12.0

 

 

$

11.6

 

 

$

54.0

 

Spire Missouri

 

 

10.1

 

 

 

9.7

 

 

 

9.3

 

 

 

8.9

 

 

 

8.5

 

 

 

38.3

 

Spire Alabama

 

 

3.2

 

 

 

3.2

 

 

 

3.1

 

 

 

3.0

 

 

 

3.0

 

 

 

15.2

 
Schedule of Health Care Cost Trend Rates

 

 

2025

 

2024

Medical cost trend assumed for next year – Spire Alabama and Spire Missouri

 

7.00%

 

6.50%

Rate to which the medical cost trend rate is assumed to decline (the ultimate medical
   cost trend rate)

 

5.00%

 

5.00%

Year the rate reaches the ultimate trend

 

2034

 

2031
Fair Value, Assets Measured on Recurring Basis

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

27.4

 

 

$

—

 

 

$

27.4

 

 

$

12.7

 

 

$

—

 

 

$

12.7

 

Equity funds - global (including U.S.)

 

 

—

 

 

 

181.5

 

 

 

181.5

 

 

 

—

 

 

 

152.4

 

 

 

152.4

 

Real asset funds

 

 

—

 

 

 

61.4

 

 

 

61.4

 

 

 

—

 

 

 

57.7

 

 

 

57.7

 

Debt securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. bond funds

 

 

50.7

 

 

 

—

 

 

 

50.7

 

 

 

55.6

 

 

 

—

 

 

 

55.6

 

U.S. government index funds

 

 

38.3

 

 

 

—

 

 

 

38.3

 

 

 

33.9

 

 

 

—

 

 

 

33.9

 

Global funds (including U.S.)

 

 

—

 

 

 

68.4

 

 

 

68.4

 

 

 

—

 

 

 

62.5

 

 

 

62.5

 

Total

 

$

116.4

 

 

$

311.3

 

 

$

427.7

 

 

$

102.2

 

 

$

272.6

 

 

$

374.8

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

13.1

 

 

$

—

 

 

$

13.1

 

 

$

1.6

 

 

$

—

 

 

$

1.6

 

U.S. stock/bond mutual funds

 

 

294.5

 

 

 

44.4

 

 

 

338.9

 

 

 

229.1

 

 

 

89.0

 

 

 

318.1

 

International fund

 

 

1.4

 

 

 

19.5

 

 

 

20.9

 

 

 

—

 

 

 

19.7

 

 

 

19.7

 

Total

 

$

309.0

 

 

$

63.9

 

 

$

372.9

 

 

$

230.7

 

 

$

108.7

 

 

$

339.4

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

10.1

 

 

$

—

 

 

$

10.1

 

 

$

9.9

 

 

$

—

 

 

$

9.9

 

Equity funds - global (including U.S.)

 

 

—

 

 

 

117.1

 

 

 

117.1

 

 

 

—

 

 

 

102.2

 

 

 

102.2

 

Real asset funds

 

 

—

 

 

 

43.1

 

 

 

43.1

 

 

 

—

 

 

 

40.2

 

 

 

40.2

 

Debt securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. bond funds

 

 

35.1

 

 

 

—

 

 

 

35.1

 

 

 

38.2

 

 

 

—

 

 

 

38.2

 

U.S. government index funds

 

 

30.2

 

 

 

—

 

 

 

30.2

 

 

 

25.2

 

 

 

—

 

 

 

25.2

 

Global funds (including U.S.)

 

 

—

 

 

 

49.2

 

 

 

49.2

 

 

 

—

 

 

 

44.1

 

 

 

44.1

 

Total

 

$

75.4

 

 

$

209.4

 

 

$

284.8

 

 

$

73.3

 

 

$

186.5

 

 

$

259.8

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

12.1

 

 

$

—

 

 

$

12.1

 

 

$

0.7

 

 

$

—

 

 

$

0.7

 

U.S. stock/bond mutual funds

 

 

239.3

 

 

 

—

 

 

 

239.3

 

 

 

224.2

 

 

 

—

 

 

$

224.2

 

Total

 

$

251.4

 

 

$

—

 

 

$

251.4

 

 

$

224.9

 

 

$

—

 

 

$

224.9

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

Cash and cash equivalents

 

$

10.2

 

 

$

—

 

 

$

10.2

 

 

$

1.7

 

 

$

—

 

 

$

1.7

 

Equity funds - global (including U.S.)

 

 

—

 

 

 

41.3

 

 

 

41.3

 

 

 

—

 

 

 

30.6

 

 

 

30.6

 

Real asset funds

 

 

—

 

 

 

11.7

 

 

 

11.7

 

 

 

—

 

 

 

10.6

 

 

 

10.6

 

Debt securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. bond funds

 

 

9.9

 

 

 

—

 

 

 

9.9

 

 

 

10.6

 

 

 

—

 

 

 

10.6

 

U.S. government index funds

 

 

5.2

 

 

 

—

 

 

 

5.2

 

 

 

5.2

 

 

 

—

 

 

 

5.2

 

Global funds (including U.S.)

 

 

—

 

 

 

12.3

 

 

 

12.3

 

 

 

—

 

 

 

11.2

 

 

 

11.2

 

Total

 

$

25.3

 

 

$

65.3

 

 

$

90.6

 

 

$

17.5

 

 

$

52.4

 

 

$

69.9

 

 

 

As of September 30, 2025

 

 

As of September 30, 2024

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

Quoted Prices

 

 

Significant

 

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

in Active

 

 

Observable

 

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

Markets

 

 

Inputs

 

 

 

 

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

 

(Level 1)

 

 

(Level 2)

 

 

Total

 

U.S. stock/bond mutual funds

 

$

49.6

 

 

$

44.4

 

 

$

94.0

 

 

$

—

 

 

$

89.0

 

 

$

89.0

 

International fund

 

 

—

 

 

 

19.5

 

 

 

19.5

 

 

 

—

 

 

 

18.5

 

 

 

18.5

 

Total

 

$

49.6

 

 

$

63.9

 

 

$

113.5

 

 

$

—

 

 

$

107.5

 

 

$

107.5

 
v3.25.3
Segment Information (Tables)
 12 Months Ended
Sep. 30, 2025
Segment Reporting Information [Line Items]  
Schedule of Information about Segment Revenue, Segment Expenses and Adjusted Earnings

The following tables present information about Spire’s segment revenue, segment expenses, and Adjusted Earnings.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2025

 

Gas Utility

 

 

Gas Marketing

 

 

Midstream

 

 

Total Reportable Segments

 

 

Other(b)

 

 

Intersegment Eliminations

 

 

Consolidated

 

Revenues from external customers

 

$

2,207.5

 

 

$

157.2

 

 

$

109.2

 

 

$

2,473.9

 

 

$

2.5

 

 

$

—

 

 

$

2,476.4

 

Intersegment revenues

 

 

0.1

 

 

 

-

 

 

 

46.3

 

 

 

46.4

 

 

 

—

 

 

 

(46.4

)

 

 

-

 

Total Operating Revenues

 

 

2,207.6

 

 

 

157.2

 

 

 

155.5

 

 

 

2,520.3

 

 

 

2.5

 

 

 

(46.4

)

 

 

2,476.4

 

Less:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Significant segment expenses:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Cost of gas sold, incl. gross receipts taxes

 

 

970.9

 

 

 

93.7

 

 

 

3.0

 

 

 

1,067.6

 

 

 

—

 

 

 

(46.4

)

 

 

1,021.2

 

  Operation and maintenance expense

 

 

467.1

 

 

 

19.4

 

 

 

45.3

 

 

 

531.8

 

 

 

10.3

 

 

 

—

 

 

 

542.1

 

Depreciation and amortization
   expense

 

 

277.6

 

 

 

1.0

 

 

 

19.2

 

 

 

297.8

 

 

 

0.4

 

 

 

—

 

 

 

298.2

 

Interest expense

 

 

137.1

 

 

 

—

 

 

 

11.6

 

 

 

148.7

 

 

 

55.4

 

 

 

—

 

 

 

204.1

 

Income tax expense (benefit)

 

 

47.4

 

 

 

11.1

 

 

 

15.7

 

 

 

74.2

 

 

 

(14.5

)

 

 

—

 

 

 

59.7

 

Other segment items (a)

 

 

76.1

 

 

 

6.1

 

 

 

4.4

 

 

 

86.6

 

 

 

(11.0

)

 

 

—

 

 

 

75.6

 

Adjusted earnings (loss) [Non-GAAP]

 

$

231.4

 

 

$

25.9

 

 

$

56.3

 

 

$

313.6

 

 

$

(38.1

)

 

$

-

 

 

$

275.5

 

Capital expenditures

 

 

816.8

 

 

 

0.1

 

 

 

106.8

 

 

 

923.7

 

 

 

(1.3

)

 

 

—

 

 

 

922.4

 

 

2024

 

Gas Utility

 

 

Gas Marketing

 

 

Midstream

 

 

Total Reportable Segments

 

 

Other(b)

 

 

Intersegment Eliminations

 

 

Consolidated

 

Revenues from external customers

 

$

2,436.2

 

 

$

99.2

 

 

$

56.9

 

 

$

2,592.3

 

 

$

0.7

 

 

$

—

 

 

$

2,593.0

 

Intersegment revenues

 

 

1.7

 

 

 

—

 

 

 

43.8

 

 

 

45.5

 

 

 

-

 

 

 

(45.5

)

 

 

-

 

Total Operating Revenues

 

 

2,437.9

 

 

 

99.2

 

 

 

100.7

 

 

 

2,637.8

 

 

 

0.7

 

 

 

(45.5

)

 

 

2,593.0

 

Less:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Significant segment expenses:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Cost of gas sold, incl. gross receipts taxes

 

 

1,238.7

 

 

 

37.1

 

 

 

1.1

 

 

 

1,276.9

 

 

 

0.1

 

 

 

(45.5

)

 

 

1,231.5

 

  Operation and maintenance expense

 

 

452.8

 

 

 

18.2

 

 

 

34.7

 

 

 

505.7

 

 

 

1.7

 

 

 

—

 

 

 

507.4

 

Depreciation and amortization
   expense

 

 

263.6

 

 

 

1.5

 

 

 

12.8

 

 

 

277.9

 

 

 

0.5

 

 

 

—

 

 

 

278.4

 

Interest expense

 

 

147.3

 

 

 

—

 

 

 

7.0

 

 

 

154.3

 

 

 

46.8

 

 

 

—

 

 

 

201.1

 

Income tax expense (benefit)

 

 

48.0

 

 

 

10.8

 

 

 

9.6

 

 

 

68.4

 

 

 

(9.7

)

 

 

—

 

 

 

58.7

 

Other segment items (a)

 

 

66.7

 

 

 

8.2

 

 

 

2.0

 

 

 

76.9

 

 

 

(8.4

)

 

 

—

 

 

 

68.5

 

Adjusted earnings (loss) [Non-GAAP]

 

$

220.8

 

 

$

23.4

 

 

$

33.5

 

 

$

277.7

 

 

$

(30.3

)

 

$

-

 

 

$

247.4

 

Capital expenditures

 

 

691.1

 

 

 

0.1

 

 

 

171.3

 

 

 

862.5

 

 

 

(1.2

)

 

 

—

 

 

 

861.3

 

 

2023

 

Gas Utility

 

 

Gas Marketing

 

 

Midstream

 

 

Total Reportable Segments

 

 

Other(b)

 

 

Intersegment Eliminations

 

 

Consolidated

 

Revenues from external customers

 

$

2,456.6

 

 

$

179.1

 

 

$

29.9

 

 

$

2,665.6

 

 

$

0.7

 

 

$

—

 

 

$

2,666.3

 

Intersegment revenues

 

 

0.3

 

 

 

—

 

 

 

36.2

 

 

 

36.5

 

 

 

—

 

 

 

(36.5

)

 

 

-

 

Total Operating Revenues

 

 

2,456.9

 

 

 

179.1

 

 

 

66.1

 

 

 

2,702.1

 

 

 

0.7

 

 

 

(36.5

)

 

 

2,666.3

 

Less:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Significant segment expenses:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Cost of gas sold, incl. gross receipts taxes

 

 

1,321.1

 

 

 

108.0

 

 

 

—

 

 

 

1,429.1

 

 

 

—

 

 

 

(36.5

)

 

 

1,392.6

 

  Operation and maintenance expense

 

 

461.8

 

 

 

19.4

 

 

 

30.5

 

 

 

511.7

 

 

 

5.9

 

 

 

—

 

 

 

517.6

 

Depreciation and amortization
   expense

 

 

244.4

 

 

 

1.5

 

 

 

8.4

 

 

 

254.3

 

 

 

0.5

 

 

 

—

 

 

 

254.8

 

Interest expense

 

 

139.9

 

 

 

—

 

 

 

8.6

 

 

 

148.5

 

 

 

37.2

 

 

 

—

 

 

 

185.7

 

Income tax expense (benefit)

 

 

32.7

 

 

 

12.8

 

 

 

3.8

 

 

 

49.3

 

 

 

(10.5

)

 

 

—

 

 

 

38.8

 

Other segment items (a)

 

 

56.5

 

 

 

(10.2

)

 

 

0.7

 

 

 

47.0

 

 

 

1.7

 

 

 

—

 

 

 

48.7

 

Adjusted earnings (loss)

 

$

200.5

 

 

$

47.6

 

 

$

14.1

 

 

$

262.2

 

 

$

(34.1

)

 

—

 

 

$

228.1

 

Capital expenditures

 

 

588.6

 

 

 

0.4

 

 

 

73.6

 

 

 

662.6

 

 

 

(0.1

)

 

 

—

 

 

 

662.5

 

 

(a) Other segment items for each reportable segment include fair value and timing adjustments, acquisition and restructuring activities, taxes other than income and gross receipt taxes, and miscellaneous income and deductions.

 

(b) All other components of the Company's consolidated information include Spire's subsidiaries engaged in the operation of a propane pipeline and risk management, among other activities, and unallocated corporate items, including certain debt and associated interest costs.
Reconciliation Of Consolidated Net Economic Earnings To Consolidated Net Income

Reconciliation of Consolidated Net Income to Consolidated Adjusted Earnings

 

2025

 

 

2024

 

 

2023

 

Net Income

 

$

271.7

 

 

$

250.9

 

 

$

217.5

 

Adjustments, pre-tax:

 

 

 

 

 

 

 

 

 

Fair value and timing adjustments

 

 

(10.4

)

 

 

(12.4

)

 

 

11.4

 

Acquisition and restructuring activities

 

 

15.2

 

 

 

7.6

 

 

 

2.5

 

Income tax adjustments

 

 

(1.0

)

 

 

1.3

 

 

 

(3.3

)

Adjusted Earnings

 

$

275.5

 

 

$

247.4

 

 

$

228.1

 
Spire Missouri [Member]  
Segment Reporting Information [Line Items]  
Schedule of Financial Data Related to Gross Receipt Taxes and Capital Expenditures

Financial data related to gross receipt taxes and capital expenditures are as follows:

 

 

 

2025

 

 

2024

 

 

2023

 

Gross Receipt Taxes

 

$

82.9

 

 

$

93.1

 

 

$

96.7

 

Capital Expenditures

 

 

641.2

 

 

 

553.0

 

 

 

447.5

 
Spire Alabama Inc [Member]  
Segment Reporting Information [Line Items]  
Schedule of Financial Data Related to Gross Receipt Taxes and Capital Expenditures

Financial data related to gross receipt taxes and capital expenditures are as follows:

 

 

2025

 

 

2024

 

 

2023

 

Gross Receipt Taxes

 

 

27.9

 

 

 

30.1

 

 

 

29.9

 

Capital Expenditures

 

 

144.2

 

 

 

112.8

 

 

 

117.6

 
v3.25.3
Regulatory Matters (Tables)
 12 Months Ended
Sep. 30, 2025
Regulated Operations [Abstract]  
Schedule of Regulatory Assets and Liabilities

The following regulatory assets and regulatory liabilities were reflected in the balance sheets of the Company, Spire Missouri and Spire Alabama as of September 30, 2025 and 2024.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

September 30

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Regulatory Assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unamortized purchased gas adjustments

 

$

16.5

 

 

$

28.9

 

 

$

14.9

 

 

$

28.1

 

 

$

—

 

 

$

—

 

Other

 

 

61.8

 

 

 

86.5

 

 

 

34.0

 

 

 

55.9

 

 

 

16.1

 

 

 

19.2

 

Total Current Regulatory Assets

 

 

78.3

 

 

 

115.4

 

 

 

48.9

 

 

 

84.0

 

 

 

16.1

 

 

 

19.2

 

Noncurrent:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Future income taxes due from customers

 

 

154.2

 

 

 

150.7

 

 

 

146.6

 

 

 

142.7

 

 

 

1.6

 

 

 

1.8

 

Pension and postretirement benefit costs

 

 

217.8

 

 

 

237.5

 

 

 

157.0

 

 

 

166.5

 

 

 

59.1

 

 

 

68.2

 

Cost of removal

 

 

688.3

 

 

 

668.2

 

 

 

98.8

 

 

 

97.0

 

 

 

589.6

 

 

 

571.2

 

Unamortized purchased gas adjustments

 

 

9.0

 

 

 

1.2

 

 

 

9.0

 

 

 

1.2

 

 

 

—

 

 

 

—

 

Energy efficiency

 

 

65.0

 

 

 

61.0

 

 

 

65.0

 

 

 

61.0

 

 

 

—

 

 

 

—

 

Other

 

 

189.2

 

 

 

133.2

 

 

 

176.8

 

 

 

119.6

 

 

 

0.3

 

 

 

0.8

 

Total Noncurrent Regulatory Assets

 

 

1,323.5

 

 

 

1,251.8

 

 

 

653.2

 

 

 

588.0

 

 

 

650.6

 

 

 

642.0

 

Total Regulatory Assets

 

$

1,401.8

 

 

$

1,367.2

 

 

$

702.1

 

 

$

672.0

 

 

$

666.7

 

 

$

661.2

 

Regulatory Liabilities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unamortized purchased gas adjustments

 

$

34.9

 

 

$

42.3

 

 

$

13.9

 

 

$

10.2

 

 

$

20.2

 

 

$

30.9

 

Other

 

 

4.5

 

 

 

7.2

 

 

 

—

 

 

 

—

 

 

 

0.1

 

 

 

2.9

 

Total Current Regulatory Liabilities

 

 

39.4

 

 

 

49.5

 

 

 

13.9

 

 

 

10.2

 

 

 

20.3

 

 

 

33.8

 

Noncurrent:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Deferred taxes due to customers

 

 

100.3

 

 

 

114.2

 

 

 

88.8

 

 

 

101.8

 

 

 

—

 

 

 

—

 

Pension and postretirement benefit costs

 

 

300.1

 

 

 

232.9

 

 

 

261.2

 

 

 

196.6

 

 

 

26.5

 

 

 

25.1

 

Accrued cost of removal

 

 

138.2

 

 

 

133.6

 

 

 

96.0

 

 

 

94.5

 

 

 

—

 

 

 

—

 

Unamortized purchased gas adjustments

 

 

6.5

 

 

 

17.2

 

 

 

6.5

 

 

 

17.2

 

 

 

—

 

 

 

—

 

Other

 

 

32.9

 

 

 

37.6

 

 

 

28.8

 

 

 

33.2

 

 

 

2.7

 

 

 

3.2

 

Total Noncurrent Regulatory Liabilities

 

 

578.0

 

 

 

535.5

 

 

 

481.3

 

 

 

443.3

 

 

 

29.2

 

 

 

28.3

 

Total Regulatory Liabilities

 

$

617.4

 

 

$

585.0

 

 

$

495.2

 

 

$

453.5

 

 

$

49.5

 

 

$

62.1

 
Schedule of Regulatory Assets Not Earning Return

A portion of the Company’s and Spire Missouri's regulatory assets are not earning a return, as shown in the table below:

 

 

 

Spire

 

 

Spire Missouri

 

September 30

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Pension and postretirement benefit costs

 

$

119.1

 

 

$

129.7

 

 

$

119.1

 

 

$

129.7

 

Future income taxes due from customers

 

 

152.7

 

 

 

148.9

 

 

 

146.6

 

 

 

142.7

 

Unamortized purchase gas adjustments

 

 

23.9

 

 

 

29.3

 

 

 

23.9

 

 

 

29.3

 

Other

 

 

177.0

 

 

 

132.5

 

 

 

177.0

 

 

 

132.5

 

Total Regulatory Assets Not Earning a Return

 

$

472.7

 

 

$

440.4

 

 

$

466.6

 

 

$

434.2

 
v3.25.3
Leases (Tables)
 12 Months Ended
Sep. 30, 2025
Leases [Abstract]  
Schedule of Operating Lease Cost, Cash Flow and Non Cash Information

Operating lease cost, cash flow and noncash information are shown in the following table.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

 

2025

 

 

2024

 

 

2023

 

Operating lease cost, including amounts
   capitalized

 

$

7.1

 

 

$

7.3

 

 

$

7.3

 

 

$

0.5

 

 

$

0.5

 

 

$

0.5

 

 

$

2.0

 

 

$

2.0

 

 

$

2.0

 

Operating cash flows representing cash
   paid for amounts included in the
   measurement of lease liabilities

 

 

7.3

 

 

 

7.4

 

 

 

7.3

 

 

 

0.5

 

 

 

0.5

 

 

 

0.5

 

 

 

2.2

 

 

 

2.1

 

 

 

2.1

 

Right-of-use assets obtained in exchange
   for lease liabilities

 

 

—

 

 

 

—

 

 

 

0.8

 

 

 

—

 

 

 

—

 

 

 

0.8

 

 

 

—

 

 

 

—

 

 

 

—

 
Schedule of Balance Sheet and Weighted Average Information About Operating Leases

The following table shows year-end balance sheet and weighted-average information about operating leases.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

 

2025

 

 

2024

 

Right-of-use assets

 

$

59.2

 

 

$

63.1

 

 

$

1.6

 

 

$

1.7

 

 

$

17.0

 

 

$

18.1

 

Lease liabilities, current

 

 

6.1

 

 

 

6.6

 

 

 

0.5

 

 

 

0.5

 

 

 

2.0

 

 

 

1.9

 

Lease liabilities, noncurrent

 

 

59.1

 

 

 

62.7

 

 

 

1.2

 

 

 

1.3

 

 

 

20.9

 

 

 

22.3

 

Weighted-average remaining lease term (in years)

 

 

12.6

 

 

 

13.5

 

 

 

4.8

 

 

 

5.1

 

 

 

11.3

 

 

 

12.3

 

Weighted-average discount rate

 

 

4.2

%

 

 

4.2

%

 

 

3.8

%

 

 

3.4

%

 

 

3.7

%

 

 

3.7

%
Lessee, Operating Lease, Liability, to be Paid, Maturity

Following is a maturity analysis by fiscal year for operating lease liabilities as of September 30, 2025.

 

 

 

Spire

 

 

Spire Missouri

 

 

Spire Alabama

 

2026

 

$

6.3

 

 

$

0.5

 

 

$

2.0

 

2027

 

 

6.7

 

 

 

0.4

 

 

 

2.3

 

2028

 

 

6.8

 

 

 

0.3

 

 

 

2.3

 

2029

 

 

6.7

 

 

 

0.3

 

 

 

2.4

 

2030

 

 

6.7

 

 

 

0.2

 

 

 

2.4

 

Thereafter

 

 

51.3

 

 

 

0.2

 

 

 

16.9

 

Total undiscounted lease payments

 

 

84.5

 

 

 

1.9

 

 

 

28.3

 

Less present value discount

 

 

(19.3

)

 

 

(0.2

)

 

 

(5.4

)

Total current and noncurrent lease liabilities

 

$

65.2

 

 

$

1.7

 

 

$

22.9

 
v3.25.3
Summary of Significant Accounting Policies - Additional Information (Details)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2023
USD ($)
Sep. 30, 2025
USD ($)
Segment
Sep. 30, 2024
USD ($)
Sep. 30, 2023
USD ($)
Accounting Policies [Line Items]        
Number of reportable segments | Segment   3    
Difference between replacement cost of gas storage and inventory basis amount   $ 21.3 $ 27.3  
Goodwill   1,171.6 1,171.6  
Restricted Cash   35.5 30.4  
Utility Plant [Member]        
Accounting Policies [Line Items]        
Utility plant, construction work-in-progress   268.3 143.2  
Non-utility Property [Member]        
Accounting Policies [Line Items]        
Depreciation   $ 32.7 $ 25.8 $ 20.6
Spire Alabama Inc [Member]        
Accounting Policies [Line Items]        
Number of reportable segments | Segment   1    
Public utilities, property, plant and equipment, disclosure of composite depreciation rate for plants in service   3.00% 3.00% 3.00%
Financing Receivable, after Allowance for Credit Loss   $ 5.4 $ 5.9  
Gas Utility [Member]        
Accounting Policies [Line Items]        
Goodwill   210.2    
Gas Marketing [Member]        
Accounting Policies [Line Items]        
Goodwill   0.0    
Midstream [Member]        
Accounting Policies [Line Items]        
Goodwill   0.0    
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Spire Alabama Inc [Member]        
Accounting Policies [Line Items]        
Financing Receivable, before Allowance for Credit Loss   $ 0.4 $ 0.4  
Other Income [Member]        
Accounting Policies [Line Items]        
Gain on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring $ 8.2      
v3.25.3
Summary of Significant Accounting Policies - Summary of Non-Utility Property (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment $ 1,136.6 $ 1,052.1
Accumulated depreciation (129.4) (96.8)
Property, plant and equipment, net 1,007.2 955.3
Storage [Member]    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment 453.8 382.0
Pipeline [Member]    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment 498.3 492.4
All Other Property [Member]    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment $ 184.5 $ 177.7
v3.25.3
Summary of Significant Accounting Policies - Summary of Accrued Capital Expenditures Excluded from Capital Expenditures in the Statements of Cash Flows (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Accounting Policies [Line Items]      
Accrued capital expenditures $ 82.5 $ 116.5 $ 104.3
Spire Missouri [Member]      
Accounting Policies [Line Items]      
Accrued capital expenditures 61.8 67.4 56.5
Spire Alabama Inc [Member]      
Accounting Policies [Line Items]      
Accrued capital expenditures $ 9.5 $ 14.1 $ 4.6
v3.25.3
Summary of Significant Accounting Policies - Summary of Asset Retirement Obligations (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Accounting Policies [Line Items]    
Asset retirement obligations, beginning of year $ 579.9 $ 577.4
Liabilities incurred during the period 3.1 2.5
Liabilities settled during the period (5.1) (6.5)
Accretion 25.0 24.8
Revisions in estimated cash flows (19.7) (18.3)
Asset retirement obligations, end of year 583.2 579.9
Spire Missouri [Member]    
Accounting Policies [Line Items]    
Asset retirement obligations, beginning of year 95.7 111.1
Liabilities incurred during the period 0.4 0.4
Liabilities settled during the period (2.8) (2.9)
Accretion 3.9 4.5
Revisions in estimated cash flows (1.7) (17.4)
Asset retirement obligations, end of year 95.5 95.7
Spire Alabama Inc [Member]    
Accounting Policies [Line Items]    
Asset retirement obligations, beginning of year 468.6 451.0
Liabilities incurred during the period 2.2 1.4
Liabilities settled during the period (0.9) (1.3)
Accretion 20.4 19.6
Revisions in estimated cash flows (20.3) (2.1)
Asset retirement obligations, end of year $ 470.0 $ 468.6
v3.25.3
Summary of Significant Accounting Policies - Transactions With Affiliates (Details) - Affiliated Entity [Member] - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Unregulated Operation [Member] | Spire S T L Pipeline L L C [Member] | Spire Missouri [Member]      
Related Party Transaction [Line Items]      
Transaction amount $ 32.0 $ 32.5 $ 32.0
Unregulated Operation [Member] | Spire S T L Pipeline L L C [Member] | Spire Alabama Inc [Member]      
Related Party Transaction [Line Items]      
Transaction amount 0.0 0.0 0.0
Unregulated Operation [Member] | Spire Storage Salt Plains LLC [Member] | Spire Missouri [Member]      
Related Party Transaction [Line Items]      
Transaction amount 0.0 0.7 0.7
Unregulated Operation [Member] | Spire Storage Salt Plains LLC [Member] | Spire Alabama Inc [Member]      
Related Party Transaction [Line Items]      
Transaction amount 0.0 0.0 0.0
Unregulated Operation [Member] | Spire MoGas Pipeline [Member] | Spire Missouri [Member]      
Related Party Transaction [Line Items]      
Transaction amount 7.0 4.8 0.0
Unregulated Operation [Member] | Spire MoGas Pipeline [Member] | Spire Alabama Inc [Member]      
Related Party Transaction [Line Items]      
Transaction amount 0.0 0.0 0.0
Regulated Operation [Member] | Spire Marketing [Member] | Spire Missouri [Member]      
Related Party Transaction [Line Items]      
Purchases of natural gas from Spire Marketing 23.8 13.9 57.4
Transaction amount 0.1 1.7 0.4
Regulated Operation [Member] | Spire Marketing [Member] | Spire Alabama Inc [Member]      
Related Party Transaction [Line Items]      
Purchases of natural gas from Spire Marketing 13.9 6.7 4.7
Transaction amount $ 0.0 $ 0.0 $ 0.0
v3.25.3
Summary of Significant Accounting Policies - Activity in the Allowance for Credit Losses (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Accounting Policies [Line Items]      
Allowance at beginning of year $ 31.4 $ 32.5 $ 31.9
Provision for expected credit losses 19.6 23.0 16.6
Write-offs, net of recoveries (22.2) (24.1) (16.0)
Allowance at end of year 28.8 31.4 32.5
Spire Missouri [Member]      
Accounting Policies [Line Items]      
Allowance at beginning of year 24.9 26.2 24.9
Provision for expected credit losses 14.8 19.0 13.3
Write-offs, net of recoveries (16.7) (20.3) (12.0)
Allowance at end of year 23.0 24.9 26.2
Spire Alabama Inc [Member]      
Accounting Policies [Line Items]      
Allowance at beginning of year 5.7 5.7 6.3
Provision for expected credit losses 4.0 3.2 2.6
Write-offs, net of recoveries (4.8) (3.2) (3.2)
Allowance at end of year $ 4.9 $ 5.7 $ 5.7
v3.25.3
Revenue - Schedule of Revenue Disaggregated by Source and Customer Type (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disaggregation of Revenue [Line Items]      
Operating Revenues $ 2,476.4 $ 2,593.0 $ 2,666.3
Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues 2,520.3 2,637.8 2,702.1
Gas Utility [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues 2,207.6 2,437.9 2,456.9
Gas Marketing [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues 157.2 99.2 179.1
Midstream [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues 155.5 100.7 66.1
Other [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues [1] 2.5 0.7 0.7
Spire [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues 2,476.4 2,593.0 2,666.3
Spire [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues 2,540.8 2,655.4 2,718.8
Spire [Member] | Intercompany Eliminations [Member]      
Disaggregation of Revenue [Line Items]      
Operating Revenues (64.4) (62.4) (52.5)
Spire [Member] | Gas Utility [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 2,187.2 2,386.6 2,422.2
Changes in accrued revenue under alternative revenue programs 20.3 51.3 34.7
Total Gas Utility operating revenues 2,207.5 2,437.9 2,456.9
Spire [Member] | Gas Utility [Member] | Operating Segments [Member] | Residential [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 1,462.6 1,617.4 1,648.5
Spire [Member] | Gas Utility [Member] | Operating Segments [Member] | Commercial and Industrial [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 501.3 581.0 606.0
Spire [Member] | Gas Utility [Member] | Operating Segments [Member] | Transportation [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 133.6 130.0 121.6
Spire [Member] | Gas Utility [Member] | Operating Segments [Member] | Off-system and Other Incentive [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 65.3 37.0 30.0
Spire [Member] | Gas Utility [Member] | Operating Segments [Member] | Other Customer Revenue [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 24.4 21.2 16.1
Spire [Member] | Gas Marketing [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Unregulated Operating Revenue 157.2 99.2 179.1
Spire [Member] | Midstream [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Unregulated Operating Revenue 155.5 100.7 66.1
Spire [Member] | Other [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Unregulated Operating Revenue 20.6 17.6 16.7
Spire Missouri [Member]      
Disaggregation of Revenue [Line Items]      
Changes in accrued revenue under alternative revenue programs 24.2 51.0 23.9
Operating Revenues 1,544.1 1,737.4 1,762.9
Spire Missouri [Member] | Gas Utility [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 1,519.9 1,686.4 1,739.0
Spire Missouri [Member] | Gas Utility [Member] | Operating Segments [Member] | Residential [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 1,092.1 1,217.7 1,261.3
Spire Missouri [Member] | Gas Utility [Member] | Operating Segments [Member] | Commercial and Industrial [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 326.0 390.9 411.9
Spire Missouri [Member] | Gas Utility [Member] | Operating Segments [Member] | Transportation [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 35.9 34.1 33.2
Spire Missouri [Member] | Gas Utility [Member] | Operating Segments [Member] | Off-system and Other Incentive [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 51.9 28.8 20.1
Spire Missouri [Member] | Gas Utility [Member] | Operating Segments [Member] | Other Customer Revenue [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 14.0 14.9 12.5
Spire Alabama Inc [Member]      
Disaggregation of Revenue [Line Items]      
Changes in accrued revenue under alternative revenue programs (3.8) 0.2 6.7
Operating Revenues 545.2 578.9 571.1
Spire Alabama Inc [Member] | Gas Utility [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 549.0 578.7 564.4
Spire Alabama Inc [Member] | Gas Utility [Member] | Operating Segments [Member] | Residential [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 307.5 336.4 322.9
Spire Alabama Inc [Member] | Gas Utility [Member] | Operating Segments [Member] | Commercial and Industrial [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 134.5 149.5 150.4
Spire Alabama Inc [Member] | Gas Utility [Member] | Operating Segments [Member] | Transportation [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 87.3 85.1 77.6
Spire Alabama Inc [Member] | Gas Utility [Member] | Operating Segments [Member] | Off-system and Other Incentive [Member]      
Disaggregation of Revenue [Line Items]      
Revenue 13.4 8.1 9.9
Spire Alabama Inc [Member] | Gas Utility [Member] | Operating Segments [Member] | Other Customer Revenue [Member]      
Disaggregation of Revenue [Line Items]      
Revenue $ 6.3 $ (0.4) $ 3.6
[1] All other components of the Company's consolidated information include Spire's subsidiaries engaged in the operation of a propane pipeline and risk management, among other activities, and unallocated corporate items, including certain debt and associated interest costs.
v3.25.3
Revenue - Schedule of Gross Receipts Taxes Associated Revenue (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disaggregation of Revenue [Line Items]      
Gross receipts tax amounts $ 115.7 $ 128.2 $ 131.8
Spire Missouri [Member]      
Disaggregation of Revenue [Line Items]      
Gross receipts tax amounts 82.9 93.1 96.7
Spire Alabama Inc [Member]      
Disaggregation of Revenue [Line Items]      
Gross receipts tax amounts $ 27.9 $ 30.1 $ 29.9
v3.25.3
Stock-based Compensation - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) 3 years    
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) 1,500,000    
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Deferred (in shares) 79,815    
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate 0.00% 0.00% 0.00%
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount $ 8.7    
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) 1 year 9 months 18 days    
Performance-contingent Restricted Share Units      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 103,780    
Granted, weighted average grant date fair value (in dollars per share) $ 76.52    
Performance-contingent Restricted Share Units | Executive Officers and Key Employees      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 103,780    
Granted, weighted average grant date fair value (in dollars per share) $ 76.52 $ 74.23 $ 79.88
Share Based Compensation Arrangement By Share Based Payment Award, Maximum Target Award Percentage 200.00%    
Share Based Compensation Arrangement By Share Based Payment Award, Number of Shares to Be Issued at Maximum Performance Target (in shares) 564,862    
Time-vested Restricted Stock      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 57,030    
Granted, weighted average grant date fair value (in dollars per share) $ 72    
Time-vested Restricted Stock | Executive Officers and Key Employees      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 57,030    
Granted, weighted average grant date fair value (in dollars per share) $ 72 60.68 71.91
Time-vested Restricted Stock | Non Employee Directors      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 15,750    
Granted, weighted average grant date fair value (in dollars per share) $ 71.38 $ 58.03 $ 75.59
Performance-contingent Restricted Stock Unit and Time-vested Restricted Stocks      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation (in shares) 26,892 24,724 18,428
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Withheld for Tax Withholding Obligations, Weighted Average Price Per Share (in dollars per share) $ 73.45 $ 60.73 $ 72.03
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value $ 8.0 $ 11.9 $ 8.6
Share Based Compensation Tax Benefit Realized From Exercise Of Equity Instruments Other Than Stock Options $ 4.0 $ 3.7 $ 3.2
v3.25.3
Stock-based Compensation - Activity of Restricted Stock Units (Details)
 12 Months Ended
Sep. 30, 2025
$ / shares
shares
Performance-contingent Restricted Share Units  
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]  
Nonvested, units (in shares) | shares 289,205
Granted, units (in shares) | shares 103,780
Adjusted for performance, units (in shares) | shares 21,469
Vested, units (in shares) | shares (100,784)
Forfeited, units (in shares) | shares (69,166)
Nonvested, units (in shares) | shares 244,504
Nonvested, weighted average grant date fair value (in dollars per share) | $ / shares $ 73.36
Granted, weighted average grant date fair value (in dollars per share) | $ / shares 76.52
Adjusted for performance, weighted average grant date fair value (in dollars per share) | $ / shares 65.02
Vested, weighted average grant date fair value (in dollars per share) | $ / shares 65.02
Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares 74.67
Nonvested, weighted average grant date fair value (in dollars per share) | $ / shares $ 75.62
Time-vested Restricted Stock  
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]  
Nonvested, units (in shares) | shares 85,559
Granted, units (in shares) | shares 57,030
Vested, units (in shares) | shares (42,677)
Forfeited, units (in shares) | shares (23,348)
Nonvested, units (in shares) | shares 76,564
Nonvested, weighted average grant date fair value (in dollars per share) | $ / shares $ 64.13
Granted, weighted average grant date fair value (in dollars per share) | $ / shares 72
Vested, weighted average grant date fair value (in dollars per share) | $ / shares 66.36
Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares 67.61
Nonvested, weighted average grant date fair value (in dollars per share) | $ / shares $ 67.2
v3.25.3
Stock-based Compensation - Schedule of Significant Assumptions (Details)
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]      
Risk-free interest rate 4.33% 4.66% 4.26%
Expected dividend yield of stock 0.00% 0.00% 0.00%
Expected volatility of stock 22.20% 23.30% 33.80%
Performance period (in years) 3 years 3 years 3 years
v3.25.3
Stock-based Compensation - Compensation Cost of Share-based Compensation Arrangements (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]      
Total compensation cost $ 7.8 $ 6.6 $ 11.2
Compensation cost capitalized (1.1) (0.8) (1.4)
Compensation cost recognized in net income 6.7 5.8 9.8
Income tax benefit recognized in net income (1.5) (1.3) (2.2)
Compensation cost recognized in net income, net of income tax $ 5.2 $ 4.5 $ 7.6
v3.25.3
Earnings Per Common Share - Earnings Per Common Share (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Earnings Per Share [Abstract]      
Net Income (Loss) $ 271.7 $ 250.9 $ 217.5
Provision for preferred dividends 14.8 14.8 14.8
Income allocated to participating securities 0.3 0.3 0.3
Net Income Available to Common Shareholders $ 256.6 $ 235.8 $ 202.4
Basic (in shares) 58.5 56.1 52.5
Basic Earnings Per Share of Common Stock (in dollars per share) $ 4.39 $ 4.2 $ 3.86
Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions) (in shares) 0.2 0.2 0.1
Weighted Average Diluted Common Shares (in millions) (in shares) 58.7 56.3 52.6
Diluted Earnings Per Share of Common Stock (in dollars per share) $ 4.37 $ 4.19 $ 3.85
Calculation excludes certain outstanding common shares (shown in millions by period at the right) attributable to common stock forward contracts, stock units subject to performance or market conditions, and restricted stock, which could have a dilutive effect in the future (in shares) 0.2 0.1 1.9
v3.25.3
Shareholders' Equity - Additional Information (Details) - USD ($)
 1 Months Ended 3 Months Ended
Mar. 05, 2024
Dec. 11, 2023
May 21, 2019
Dec. 31, 2024
Feb. 28, 2021
Sep. 30, 2024
Oct. 23, 2025
Sep. 30, 2025
Mar. 31, 2025
Mar. 01, 2024
Jan. 25, 2024
Sep. 30, 2022
Class of Stock [Line Items]                        
Preferred Stock, Shares Authorized (in shares)           5,000,000   5,000,000        
Number of Shares Authorized for Issuance (in shares)               250,000        
Number Of Shares Remaining and Available for Issuance (in shares)           218,141   196,135        
Retained Earnings Dividend Restrictions Formula Component Fixed Amount                       $ 8,000,000
Retained Earnings, Unappropriated           $ 1,797,000,000   $ 1,999,400,000        
Common stock           $ 57,700,000   $ 59,000,000        
Spire Missouri [Member]                        
Class of Stock [Line Items]                        
Preferred Stock, Shares Authorized (in shares)           1,480,000   1,480,000        
Regulatory Preferred Stock and Debt Securities Issuance Amount Authorized               $ 850,000,000        
Preferred Stock, Shares Issued (in shares)           0   0        
Common stock           $ 100,000   $ 100,000        
Spire Missouri [Member] | Subsequent Event [Member]                        
Class of Stock [Line Items]                        
Common stock             $ 74,400,000          
Spire Alabama Inc [Member]                        
Class of Stock [Line Items]                        
Preferred Stock, Shares Authorized (in shares)           120,000   120,000        
Preferred Stock, Shares Issued (in shares)           0   0        
At The Market Program [Member]                        
Class of Stock [Line Items]                        
Forward Sales Agreements, Shares Settled (in shares)   1,744,549   542,515                
Proceeds from Shares Settled   $ 112,200,000   $ 32,400,000                
Sale of Stock, Maximum Aggregate Offering Price               $ 123,600,000     $ 200,000,000  
Forward Sales Agreements, Shares (in shares)           663,619            
Forward Sales Agreements, Proceeds If Settled                 $ 42,400,000      
First Mortgage Bond [Member] | Spire Missouri [Member] | Subsequent Event [Member]                        
Class of Stock [Line Items]                        
Debt Instrument face amount             350,000,000          
Parent Company [Member] | Two Thousand Twenty One Series A Zero Point Seven Five Percentage Remarketable Senior Notes [Member]                        
Class of Stock [Line Items]                        
Debt Instrument face amount         $ 1,000              
Debt Instrument, Interest Rate, Stated Percentage         0.75%              
Parent Company [Member] | First Mortgage Bond [Member] | Subsequent Event [Member]                        
Class of Stock [Line Items]                        
Debt Instrument face amount             $ 150,000,000          
Depositary Shares [Member]                        
Class of Stock [Line Items]                        
Preferred Stock, Shares Authorized (in shares)           10,000,000   10,000,000        
Preferred Stock, Shares Outstanding, Ending Balance (in shares)     10,000,000     10,000,000   10,000,000        
Fractional Interest In Share Of Series A Preferred Stock     0.001%                  
Preferred Stock, Par or Stated Value Per Share (in dollars per share)           $ 25   $ 25        
Preferred Stock, Liquidation Preference Per Share (in dollars per share)     $ 25                  
Preferred Stock, Shares Issued (in shares)           10,000,000   10,000,000        
Series A Preferred Stock [Member]                        
Class of Stock [Line Items]                        
Preferred Stock, Dividend Rate, Percentage     5.90%                  
Preferred Stock, Par or Stated Value Per Share (in dollars per share)     $ 25                  
Preferred Stock, Liquidation Preference Per Share (in dollars per share)     $ 25,000                  
Stock Issued During Period, Shares, New Issues (in shares)     10,000                  
Proceeds from Issuance of Preferred Stock and Preference Stock     $ 242,000,000                  
Preferred Stock, Redemption Price Per Share (in dollars per share)               $ 25,000        
Corporate Unit [Member] | Parent Company [Member]                        
Class of Stock [Line Items]                        
Stock Issued During Period, Shares, New Issues (in shares) 2,745,733       3,500,000              
Equity Units, Stated Value (in dollars per share)         $ 50              
Percentage of Undivided Beneficial Ownership Interest         5.00%              
Equity Units, Applicable Market Value (in dollars per share)                   $ 58.6809    
Equity Units, Number of Common Stock Obligated to be Purchased After Adjustment (in shares)                   0.7845    
Equity Stock Units Issued $ 175,000,000                      
v3.25.3
Shareholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Class of Stock [Line Items]      
Balance $ 3,232.7 $ 2,917.3 $ 2,818.5
Other comprehensive (loss) income 7.3 (35.5) 0.4
Balance 3,389.4 3,232.7 2,917.3
Spire Missouri [Member]      
Class of Stock [Line Items]      
Balance 1,963.7 1,844.8 1,745.4
Other comprehensive (loss) income 1.3 0.5 0.2
Balance 2,167.7 1,963.7 1,844.8
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]      
Class of Stock [Line Items]      
Balance 14.2 50.5  
Other comprehensive (loss) income 5.9 (36.3)  
Balance 20.1 14.2 50.5
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Spire Missouri [Member]      
Class of Stock [Line Items]      
Balance 0.0 0.0  
Other comprehensive (loss) income 0.0 0.0  
Balance 0.0 0.0 0.0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]      
Class of Stock [Line Items]      
Balance (2.0) (2.5)  
Other comprehensive (loss) income 1.3 0.5  
Balance (0.7) (2.0) (2.5)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Spire Missouri [Member]      
Class of Stock [Line Items]      
Balance (2.0) (2.5)  
Other comprehensive (loss) income 1.3 0.5  
Balance (0.7) (2.0) (2.5)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]      
Class of Stock [Line Items]      
Balance (0.1) (0.4)  
Other comprehensive (loss) income 0.1 0.3  
Balance 0.0 (0.1) (0.4)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] | Spire Missouri [Member]      
Class of Stock [Line Items]      
Balance 0.0 0.0  
Other comprehensive (loss) income 0.0 0.0  
Balance 0.0 0.0 0.0
AOCI Attributable to Parent [Member]      
Class of Stock [Line Items]      
Balance 12.1 47.6 47.2
Other comprehensive (loss) income 7.3 (35.5) 0.4
Balance 19.4 12.1 47.6
AOCI Attributable to Parent [Member] | Spire Missouri [Member]      
Class of Stock [Line Items]      
Balance (2.0) (2.5) (2.7)
Other comprehensive (loss) income 1.3 0.5 0.2
Balance $ (0.7) $ (2.0) $ (2.5)
v3.25.3
Long-term Debt Details - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Oct. 23, 2025
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Long-Term Debt, Gross   $ 3,879.1 $ 3,771.1  
Interest Paid, Capitalized, Investing Activities   19.5 17.0 $ 8.6
Common stock   59.0 57.7  
Spire and Other Subsidiaries [Member]        
Long-Term Debt, Gross   1,196.1    
Parent Company [Member] | First Mortgage Bond [Member] | Subsequent Event [Member]        
Debt Instrument face amount $ 150.0      
Debt Instrument, Payment Terms semi-annually on March 15 and September 15 of each year      
Parent Company [Member] | First Mortgage Bond [Member] | Share-Based Payment Arrangement, Tranche One [Member] | Subsequent Event [Member]        
Debt Instrument face amount $ 200.0      
Debt instrument interest rate 4.60%      
Debt instrument maturity date Sep. 15, 2030      
Parent Company [Member] | First Mortgage Bond [Member] | Share-Based Payment Arrangement, Tranche Two [Member] | Subsequent Event [Member]        
Debt Instrument face amount $ 50.0      
Debt instrument interest rate 4.65%      
Debt instrument maturity date Jan. 15, 2031      
Spire Missouri [Member]        
Long-Term Debt, Gross   1,968.0 1,818.0  
Interest Paid, Capitalized, Investing Activities   4.8 4.6 3.1
Regulatory Preferred Stock and Debt Securities Issuance Amount Authorized   850.0    
Common stock   0.1 0.1  
Spire Missouri [Member] | Subsequent Event [Member]        
Common stock $ 74.4      
Debt available for issuance under authorization 426.0      
Spire Missouri [Member] | First Mortgage Bond [Member] | Subsequent Event [Member]        
Debt Instrument face amount $ 350.0      
Spire Alabama Inc [Member]        
Long-Term Debt, Gross   715.0 750.0  
Interest Paid, Capitalized, Investing Activities   $ 4.5 $ 1.8 $ 2.3
v3.25.3
Long-term Debt - Schedule of Long-Term Debt Instruments (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Total principal of long-term debt $ 3,879.1 $ 3,771.1
Less: Unamortized discounts and debt issuance costs (22.2) (24.7)
Less: Current portion (487.5) (42.0)
Long-term debt (less current portion) 3,369.4 3,704.4
Spire Missouri [Member]    
Total principal of long-term debt 1,968.0 1,818.0
Less: Unamortized discounts and debt issuance costs (14.4) (14.6)
Long-term debt (less current portion) 1,953.6 1,803.4
Spire Alabama Inc [Member]    
Total principal of long-term debt 715.0 750.0
Less: Unamortized discounts and debt issuance costs (3.3) (3.7)
Less: Current portion 0.0 (35.0)
Long-term debt (less current portion) 711.7 711.3
First Mortgage Bonds 3.40% Series, due March 15, 2028 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 45.0 45.0
First Mortgage Bonds 7.00% Series, due June 1, 2029 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 19.3 19.3
First Mortgage Bonds 2.84% Series, due November 15, 2029 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 275.0 275.0
First Mortgage Bonds 4.88% Series, due September 15, 2030 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 90.0 0.0
First Mortgage Bonds 7.90% Series, due September 15, 2030 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 30.0 30.0
First Mortgage Bonds 5.12% Series, due September 15, 2032 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 60.0 0.0
First Mortgage Bonds 3.68% Series, due September 15, 2032 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 50.0 50.0
First Mortgage Bonds 4.80% Series, due February 15, 2033 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 400.0 400.0
First Mortgage Bonds 6.00% Series, due May 1, 2034 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 99.3 99.3
First Mortgage Bonds 5.15% Series, due August 15, 2034 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 320.0 320.0
First Mortgage Bonds 6.15% Series, due June 1, 2036 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 54.5 54.5
First Mortgage Bonds 4.63% Series, due August 15, 2043 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 99.9 99.9
First Mortgage Bonds 4.23% Series, due September 15, 2047 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 70.0 70.0
First Mortgage Bonds 3.30% Series, due June 1, 2051 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 305.0 305.0
First Mortgage Bonds 4.38% Series, due September 15, 2057 [Member] | Spire Missouri [Member]    
Total principal of long-term debt 50.0 50.0
3.21% Notes, due September 15, 2025 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 0.0 35.0
5.32% Notes, due October 15, 2029 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 90.0 90.0
2.88% Notes, due December 1, 2029 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 100.0 100.0
2.04% Notes, due December 15, 2030 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 150.0 150.0
5.41% Notes, due October 15, 2032 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 85.0 85.0
5.90% Notes, due January 15, 2037 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 45.0 45.0
4.31% Notes, due December 1, 2045 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 80.0 80.0
3.92% Notes, due January 15, 2048 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 45.0 45.0
4.64% Notes, due January 15, 2049 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 90.0 90.0
4.02% Notes, due January 15, 2058 [Member] | Spire Alabama Inc [Member]    
Total principal of long-term debt 30.0 30.0
Parent Company [Member] | 5.30% Senior Notes, due March 1, 2026 [Member]    
Total principal of long-term debt 350.0 350.0
Parent Company [Member] | 3.13% Senior Notes, due September 1, 2026 [Member]    
Total principal of long-term debt 130.0 130.0
Parent Company [Member] | 3.93% Senior Notes, due March 15, 2027 [Member]    
Total principal of long-term debt 100.0 100.0
Parent Company [Member] | 5.80% Senior Notes, due March 15, 2033 [Member]    
Total principal of long-term debt 150.0 150.0
Parent Company [Member] | 4.70% Senior Notes, due August 15, 2044 [Member]    
Total principal of long-term debt 250.0 250.0
Subsidiaries [Member] | 5.00% First Mortgage Bonds, due September 30, 2031 [Member]    
Total principal of long-term debt 42.0 42.0
Subsidiaries [Member] | 2.95% Notes, with annual principal payments through December 2034 [Member]    
Total principal of long-term debt 104.1 111.1
Subsidiaries [Member] | 5.61% First Mortgage Bonds, due October 15, 2037 [Member]    
Total principal of long-term debt 30.0 30.0
Subsidiaries [Member] | 3.52% First Mortgage Bonds, due September 30, 2049 [Member]    
Total principal of long-term debt $ 40.0 $ 40.0
v3.25.3
Long-term Debt - Schedule of Long-Term Debt Instruments (Parentheticals) (Details)
 12 Months Ended
Sep. 30, 2025
First Mortgage Bonds 3.40% Series, due March 15, 2028 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.40%
Debt instrument maturity date Mar. 15, 2028
First Mortgage Bonds 7.00% Series, due June 1, 2029 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 7.00%
Debt instrument maturity date Jun. 01, 2029
First Mortgage Bonds 2.84% Series, due November 15, 2029 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 2.84%
Debt instrument maturity date Nov. 15, 2029
First Mortgage Bonds 4.88% Series, due September 15, 2030 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.88%
Debt instrument maturity date Sep. 15, 2030
First Mortgage Bonds 7.90% Series, due September 15, 2030 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 7.90%
Debt instrument maturity date Sep. 15, 2030
First Mortgage Bonds 5.12% Series, due September 15, 2032 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.12%
Debt instrument maturity date Sep. 15, 2032
First Mortgage Bonds 3.68% Series, due September 15, 2032 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.68%
Debt instrument maturity date Sep. 15, 2032
First Mortgage Bonds 4.80% Series, due February 15, 2033 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.80%
Debt instrument maturity date Feb. 15, 2033
First Mortgage Bonds 6.00% Series, due May 1, 2034 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 6.00%
Debt instrument maturity date May 01, 2034
First Mortgage Bonds 5.15% Series, due August 15, 2034 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.15%
Debt instrument maturity date Aug. 15, 2034
First Mortgage Bonds 6.15% Series, due June 1, 2036 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 6.15%
Debt instrument maturity date Jun. 01, 2036
First Mortgage Bonds 4.63% Series, due August 15, 2043 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.63%
Debt instrument maturity date Aug. 15, 2043
First Mortgage Bonds 4.23% Series, due September 15, 2047 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.23%
Debt instrument maturity date Sep. 15, 2047
First Mortgage Bonds 3.30% Series, due June 1, 2051 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.30%
Debt instrument maturity date Jun. 01, 2051
First Mortgage Bonds 4.38% Series, due September 15, 2057 [Member] | Spire Missouri [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.38%
Debt instrument maturity date Sep. 15, 2057
3.21% Notes, due September 15, 2025 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.21%
Debt instrument maturity date Sep. 15, 2025
5.32% Notes, due October 15, 2029 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.32%
Debt instrument maturity date Oct. 15, 2029
2.88% Notes, due December 1, 2029 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 2.88%
Debt instrument maturity date Dec. 01, 2029
2.04% Notes, due December 15, 2030 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 2.04%
Debt instrument maturity date Dec. 15, 2030
5.41% Notes, due October 15, 2032 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.41%
Debt instrument maturity date Oct. 15, 2032
5.90% Notes, due January 15, 2037 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.90%
Debt instrument maturity date Jan. 15, 2037
4.31% Notes, due December 1, 2045 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.31%
Debt instrument maturity date Dec. 01, 2045
3.92% Notes, due January 15, 2048 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.92%
Debt instrument maturity date Jan. 15, 2048
4.64% Notes, due January 15, 2049 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.64%
Debt instrument maturity date Jan. 15, 2049
4.02% Notes, due January 15, 2058 [Member] | Spire Alabama Inc [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.02%
Debt instrument maturity date Jan. 15, 2058
Parent Company [Member] | 5.30% Senior Notes, due March 1, 2026 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.30%
Debt instrument maturity date Mar. 01, 2026
Parent Company [Member] | 3.13% Senior Notes, due September 1, 2026 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.13%
Debt instrument maturity date Sep. 01, 2026
Parent Company [Member] | 3.93% Senior Notes, due March 15, 2027 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.93%
Debt instrument maturity date Mar. 15, 2027
Parent Company [Member] | 5.80% Senior Notes, due March 15, 2033 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.80%
Debt instrument maturity date Mar. 15, 2033
Parent Company [Member] | 4.70% Senior Notes, due August 15, 2044 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 4.70%
Debt instrument maturity date Aug. 15, 2044
Subsidiaries [Member] | 5.00% First Mortgage Bonds, due September 30, 2031 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.00%
Debt instrument maturity date Sep. 30, 2031
Subsidiaries [Member] | 2.95% Notes, with annual principal payments through December 2034 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 2.95%
Debt instrument maturity date Dec. 31, 2034
Subsidiaries [Member] | 5.61% First Mortgage Bonds, due October 15, 2037 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 5.61%
Debt instrument maturity date Oct. 15, 2037
Subsidiaries [Member] | 3.52% First Mortgage Bonds, due September 30, 2049 [Member]  
Debt Instrument [Line Items]  
Debt instrument interest rate 3.52%
Debt instrument maturity date Sep. 30, 2049
v3.25.3
Long-term Debt - Maturities of Long-term Debt (Details)
$ in Millions
Sep. 30, 2025
USD ($)
2026 $ 487.5
2027 108.1
2028 53.6
2029 28.5
2030 594.9
Spire Missouri [Member]  
2026 0.0
2027 0.0
2028 45.0
2029 19.3
2030 395.0
Spire Alabama Inc [Member]  
2026 0.0
2027 0.0
2028 0.0
2029 0.0
2030 $ 190.0
v3.25.3
Notes Payable and Credit Agreements - Additional Information (Details) - USD ($)
$ in Millions
May 06, 2024
Apr. 05, 2024
Jan. 03, 2024
Sep. 30, 2025
Sep. 30, 2024
Short-Term Debt [Line Items]          
Borrowings outstanding       $ 1,317.0 $ 947.0
Commercial Paper [Member] | Parent Company [Member]          
Short-Term Debt [Line Items]          
Short term borrowings used to support lending to utilities       741.0  
Borrowings outstanding       1,317.0 947.0
Maximum [Member] | Commercial Paper [Member]          
Short-Term Debt [Line Items]          
Borrowings outstanding       1,500.0  
Spire Missouri [Member] | Loans Payable [Member]          
Short-Term Debt [Line Items]          
Debt Instrument face amount     $ 200.0    
Repayments of Debt $ 150.0 $ 50.0      
Spire Missouri [Member] | Loans Payable [Member] | Secured Overnight Financing Rate (SOFR) [Member]          
Short-Term Debt [Line Items]          
Debt instrument basis spread on variable rate     0.10%    
Spire Missouri [Member] | Loans Payable [Member] | Adjusted SOFR [Member[          
Short-Term Debt [Line Items]          
Debt instrument basis spread on variable rate     0.90%    
Revolving Credit Facility [Member]          
Short-Term Debt [Line Items]          
Line of credit facility maximum borrowing capacity       $ 1,500.0  
Line of credit facility covenant percentage of total capitalization       65.00%  
Long-term line of credit       $ 0.0 $ 0.0
Revolving Credit Facility [Member] | Maximum [Member]          
Short-Term Debt [Line Items]          
Line of credit facility covenant percentage of total capitalization       70.00%  
Revolving Credit Facility [Member] | Spire [Member]          
Short-Term Debt [Line Items]          
Line of credit facility maximum borrowing capacity       $ 525.0  
Revolving Credit Facility [Member] | Spire Missouri [Member]          
Short-Term Debt [Line Items]          
Line of credit facility maximum borrowing capacity       700.0  
Revolving Credit Facility [Member] | Spire Alabama Inc [Member]          
Short-Term Debt [Line Items]          
Line of credit facility maximum borrowing capacity       $ 275.0  
v3.25.3
Notes Payable and Credit Agreements - Short-term Borrowings (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Short-Term Debt [Line Items]    
Highest borrowings outstanding $ 1,348.0  
Lowest borrowings outstanding 896.0  
Weighted average borrowings $ 1,085.7  
Weighted average interest rate 4.40%  
Borrowings outstanding $ 1,317.0 $ 947.0
Weighted average interest rate 4.50% 5.20%
Spire Note [Member] | Spire Missouri [Member]    
Short-Term Debt [Line Items]    
Highest borrowings outstanding $ 615.0  
Lowest borrowings outstanding 299.5  
Weighted average borrowings $ 482.6  
Weighted average interest rate 4.40%  
Borrowings outstanding $ 566.3 $ 495.3
Weighted average interest rate 4.70% 5.20%
Spire Note [Member] | Spire Alabama Inc [Member]    
Short-Term Debt [Line Items]    
Highest borrowings outstanding $ 130.6  
Lowest borrowings outstanding 1.2  
Weighted average borrowings $ 50.8  
Weighted average interest rate 4.40%  
Borrowings outstanding $ 130.1 $ 48.4
Weighted average interest rate 4.70% 5.20%
Parent Company [Member] | Commercial Paper [Member]    
Short-Term Debt [Line Items]    
Highest borrowings outstanding $ 1,348.0  
Lowest borrowings outstanding 896.0  
Weighted average borrowings $ 1,085.7  
Weighted average interest rate 4.40%  
Borrowings outstanding $ 1,317.0 $ 947.0
Weighted average interest rate 4.50% 5.20%
v3.25.3
Fair Value of Financial Instruments - Schedule of Estimated Fair Value of Financial Instruments Not Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Reported Value Measurement [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents $ 5.7 $ 4.5
Notes payable 1,317.0 947.0
Long-term debt, including current portion 3,856.9 3,746.4
Reported Value Measurement [Member] | Spire Missouri [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes payable - associated companies 566.3 495.3
Long-term debt, including current portion 1,953.6 1,803.4
Reported Value Measurement [Member] | Spire Alabama Inc [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 1.9 1.5
Notes payable - associated companies 130.1 48.4
Long-term debt, including current portion 711.7 746.3
Estimate of Fair Value Measurement [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 5.7 4.5
Notes payable 1,317.0 947.0
Long-term debt, including current portion 3,691.5 3,600.3
Estimate of Fair Value Measurement [Member] | Spire Missouri [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes payable - associated companies 566.3 495.3
Long-term debt, including current portion 1,874.0 1,736.9
Estimate of Fair Value Measurement [Member] | Spire Alabama Inc [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 1.9 1.5
Notes payable - associated companies 130.1 48.4
Long-term debt, including current portion 675.9 711.8
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 5.7 4.5
Notes payable 0.0 0.0
Long-term debt, including current portion 0.0 0.0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes payable - associated companies 0.0 0.0
Long-term debt, including current portion 0.0 0.0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 1.9 1.5
Notes payable - associated companies 0.0 0.0
Long-term debt, including current portion 0.0 0.0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 0.0 0.0
Notes payable 1,317.0 947.0
Long-term debt, including current portion 3,691.5 3,600.3
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes payable - associated companies 566.3 495.3
Long-term debt, including current portion 1,874.0 1,736.9
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash and cash equivalents 0.0 0.0
Notes payable - associated companies 130.1 48.4
Long-term debt, including current portion $ 675.9 $ 711.8
v3.25.3
Fair Value Measurements - Schedule of Derivative Assets and Liabilities, Including Receivables and Payables (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Total $ 52.1 $ 43.3
Total 38.6 32.3
Fair Value, Recurring [Member]    
Effects of netting, asset (17.0) (13.9)
Total $ 131.6 $ 113.3
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Investments Other Investments
Effects of netting, liability $ (23.0) $ (25.0)
Total $ 38.6 $ 32.3
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Other libilities Other libilities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Derivative asset fair value gross asset $ 93.8 $ 80.4
Derivative liability fair value gross liability 44.9 31.3
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]    
Derivative asset fair value gross asset 54.8 46.8
Derivative liability fair value gross liability 16.7 26.0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Gas Utility [Member]    
Effects of netting, asset 0.0 0.0
Total 27.5 24.3
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Other Operating Segment [Member]    
Effects of netting, asset 0.0 0.0
Total 27.0 17.9
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Gas Utility [Member]    
Derivative asset fair value gross asset 27.5 24.3
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 27.0 17.9
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Utility [Member]    
Derivative asset fair value gross asset 0.0 0.0
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Utility [Member]    
Derivative asset fair value gross asset 0.0 0.0
U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Gas Utility [Member]    
Effects of netting, asset (2.9) (3.4)
Total 0.0 0.0
Effects of netting, liability (1.3) (3.8)
Total 24.6 9.8
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Gas Marketing [Member]    
Effects of netting, asset (11.4) (7.0)
Total 0.0 0.0
Effects of netting, liability (19.0) (17.7)
Total 0.0 0.0
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Gas Utility [Member]    
Derivative asset fair value gross asset 2.9 3.4
Derivative liability fair value gross liability 25.9 13.6
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Gas Marketing [Member]    
Derivative asset fair value gross asset 11.4 7.0
Derivative liability fair value gross liability 19.0 17.7
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Utility [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Marketing [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Utility [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Marketing [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
Natural Gas Commodity Contracts [Member] | Fair Value, Recurring [Member] | Gas Marketing [Member]    
Effects of netting, asset (2.7) (3.5)
Total 42.1 42.5
Effects of netting, liability (2.7) (3.5)
Total 14.0 21.0
Natural Gas Commodity Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Gas Marketing [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
Natural Gas Commodity Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Marketing [Member]    
Derivative asset fair value gross asset 44.8 46.0
Derivative liability fair value gross liability 16.7 24.5
Natural Gas Commodity Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Marketing [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
U.S. Bonds [Member] | Fair Value, Recurring [Member] | Other Operating Segment [Member]    
Total 23.5 21.9
U.S. Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 23.5 21.9
U.S. Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
U.S. Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
Global Bonds [Member] | Fair Value, Recurring [Member] | Other Operating Segment [Member]    
Effects of netting, asset 0.0 0.0
Total 1.5 5.9
Global Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 1.5 5.9
Global Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
Global Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Other Operating Segment [Member]    
Effects of netting, asset 0.0 0.0
Total 10.0 0.8
Effects of netting, liability   0.0
Total   1.5
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability   0.0
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 10.0 0.8
Derivative liability fair value gross liability   1.5
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Operating Segment [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability   0.0
Spire Missouri [Member]    
Total 0.0 0.0
Total 24.6 9.8
Spire Missouri [Member] | Fair Value, Recurring [Member]    
Effects of netting, asset (2.9) (3.4)
Total $ 27.5 $ 24.3
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Property and Investments Other Property and Investments
Spire Missouri [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Derivative asset fair value gross asset $ 30.4 $ 27.7
Spire Missouri [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Spire Missouri [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Spire Missouri [Member] | U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member]    
Effects of netting, asset 0.0 0.0
Total 27.5 24.3
Spire Missouri [Member] | U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Derivative asset fair value gross asset 27.5 24.3
Spire Missouri [Member] | U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Spire Missouri [Member] | U S Stock And Bond Mutual Funds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Spire Missouri [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member]    
Effects of netting, asset (2.9) (3.4)
Total 0.0 0.0
Effects of netting, liability (1.3) (3.8)
Total 24.6 9.8
Spire Missouri [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Derivative asset fair value gross asset 2.9 3.4
Derivative liability fair value gross liability 25.9 13.6
Spire Missouri [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability 0.0 0.0
Spire Missouri [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]    
Derivative asset fair value gross asset 0.0 0.0
Derivative liability fair value gross liability $ 0.0 $ 0.0
v3.25.3
Derivative Instruments and Hedging Activities - Additional Information (Details)
MMBTU in Thousands, $ in Millions
 12 Months Ended
Sep. 30, 2025
USD ($)
MMBTU
Derivative Instruments and Hedging Activities Disclosures [Line Items]  
Nonmonetary Notional Amount of Natural Gas Derivative Contracts Not Designated As Normal Purchases Or Normal Sales (Millions of Barrels of Oil Equivalent) 278,200
Notional Amount of Non Exchange Traded Natural Gas Commodity Contracts To Be Settled In Next Twelve Months (Millions of Barrels of Oil Equivalent) 236,700
Notional Amount of Non Exchange Traded Natural Gas Commodity Contracts To Be Settled In Year Two (Millions of Barrels of Oil Equivalent) 29,700
Notional Amount of Non Exchange Traded Natural Gas Commodity Contracts To Be Settled In Year Three (Millions of Barrels of Oil Equivalent) 8,200
Notional Amount of Non Exchange Traded Natural Gas Commodity Contracts To Be Settled In Year Four (Millions of Barrels of Oil Equivalent) 3,400
Notional Amount of Non Exchange Traded Natural Gas Commodity Contracts To Be Settled In Year Five (Millions of Barrels of Oil Equivalent) 200
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax | $ $ 10.0
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent | $ $ 2.6
Spire Missouri [Member]  
Derivative Instruments and Hedging Activities Disclosures [Line Items]  
Nonmonetary Notional Amount of Other Price Mitigation in Place Not Designated As Normal Purchases Or Normal Sales (Millions of Barrels of Oil Equivalent) 9,780
v3.25.3
Derivative Instruments and Hedging Activities - Interest Swap Contracts (Details) - Cash Flow Hedging [Member]
$ in Millions
 12 Months Ended
Sep. 30, 2025
USD ($)
Interest Rate Swap Agreement One [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.018%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Two [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.40%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Three [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.525%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Four [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.535%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Five [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.45%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Six [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.541%
Derivative, mark-to-market gain $ 0.7
Interest Rate Swap Agreement Seven [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.552%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Eight [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.426%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Nine [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.577%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Ten [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.45%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Eleven [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.35%
Derivative, mark-to-market gain $ 0.8
Interest Rate Swap Agreement Twelve [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 1 year 6 months
Derivative, notional amount $ 125.0
Derivative, fixed interest rate 3.567%
Derivative, mark-to-market gain $ 0.2
Interest Rate Swap Agreement Thirteen [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 1 year 6 months
Derivative, notional amount $ 225.0
Derivative, fixed interest rate 3.567%
Derivative, mark-to-market gain $ 0.4
Interest Rate Swap Agreement Fourteen [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.58%
Derivative, mark-to-market gain $ 0.3
Interest Rate Swap Agreement Fifteen [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.611%
Derivative, mark-to-market gain $ 0.3
Interest Rate Swap Agreement Sixteen [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.657%
Derivative, mark-to-market gain $ 0.3
Interest Rate Swap Agreement Seventeen [Member]  
Derivative [Line Items]  
Derivative, hedge term (Year) 10 years
Derivative, notional amount $ 25.0
Derivative, fixed interest rate 3.763%
Derivative, mark-to-market gain $ 0.5
Interest Rate Swap [Member]  
Derivative [Line Items]  
Derivative, notional amount 725.0
Derivative, mark-to-market gain $ 10.7
v3.25.3
Derivative Instruments and Hedging Activities - Summary of NYMEX and ICE Natural Gas Futures and Swap Positions (Details) - MMBTU
MMBTU in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Natural Gas Futures Purchased [Member] | Spire Missouri [Member]    
Derivative [Line Items]    
Notional Amount, Energy Measure (Millions of British Thermal Unit) 32.3 34.6
Derivative, hedge term (Year) 12 months 12 months
Natural Gas Futures Purchased [Member] | Gas Marketing [Member]    
Derivative [Line Items]    
Notional Amount, Energy Measure (Millions of British Thermal Unit) 48.0 56.0
Derivative, hedge term (Year) 48 months 48 months
Natural Gas Futures Purchased [Member] | Gas Utility [Member]    
Derivative [Line Items]    
Notional Amount, Energy Measure (Millions of British Thermal Unit) 32.3 34.6
Derivative, hedge term (Year) 12 months 12 months
Natural Gas Options Purchased Net [Member] | Gas Marketing [Member]    
Derivative [Line Items]    
Notional Amount, Energy Measure (Millions of British Thermal Unit) 9.9 3.8
Derivative, hedge term (Year) 15 months 15 months
Natural Gas Basis Swaps Purchased [Member] | Gas Marketing [Member]    
Derivative [Line Items]    
Notional Amount, Energy Measure (Millions of British Thermal Unit) 24.7 32.4
Derivative, hedge term (Year) 39 months 39 months
v3.25.3
Derivative Instruments and Hedging Activities - Effect of Derivative Instruments on the Consolidated Statements of Income and Comprehensive Income (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Derivative [Line Items]      
Net hedging gain (loss) arising during the period $ 12.8 $ (15.9) $ 20.1
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]      
Derivative [Line Items]      
Net hedging gain (loss) arising during the period (9.6) (4.1) (16.7)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member]      
Derivative [Line Items]      
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Loss Effective Portion Net 5.1 11.1 2.4
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Other Comprehensive Income (Loss) [Member]      
Derivative [Line Items]      
Net hedging gain (loss) arising during the period 12.8 (15.9) 20.1
Not Designated as Hedging Instrument [Member] | Gasoline And Heating Oil Contracts [Member] | Non Regulated Gas Marketing Operating Revenue [Member]      
Derivative [Line Items]      
Derivatives Not Designated as Hedging Instrument (0.3) 0.3
Not Designated as Hedging Instrument [Member] | Natural Gas Commodity Contracts [Member] | Non Regulated Gas Marketing Operating Revenue [Member]      
Derivative [Line Items]      
Derivatives Not Designated as Hedging Instrument [1] (6.5) 12.5 18.0
Not Designated as Hedging Instrument [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Non Regulated Gas Marketing Operating Revenue [Member]      
Derivative [Line Items]      
Derivatives Not Designated as Hedging Instrument [1] $ (3.1) $ (16.3) $ (35.0)
[1] Gains and losses on Spire Missouri’s natural gas derivative instruments, which are not designated as hedging instruments for financial reporting purposes, are deferred pursuant to the Missouri Utilities’ PGA clauses and initially recorded as regulatory assets or regulatory liabilities. These gains and losses are excluded from the table above because they have no direct impact on the statements of income. Such amounts are recognized in the statements of income as a component of natural gas operating expenses when they are recovered through the PGA clause and reflected in customer billings.
v3.25.3
Derivative Instruments and Hedging Activities - Fair Value of Derivative Instruments in the Consolidated Balance Sheets (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above $ 69.1 $ 57.2
Fair Value Of Derivative Liability [1] 61.6 57.3
Spire Missouri [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 2.9 3.4
Fair Value Of Derivative Liability 25.9 13.6
Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 10.0 0.8
Fair Value Of Derivative Liability [1] 0.0 1.5
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Derivative Instruments Assets [Member] | Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 10.0  
Fair Value Of Derivative Liability [1] 0.0  
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Derivative Instruments Liability [Member] | Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above   0.8
Fair Value Of Derivative Liability [1]   1.5
Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 59.1 56.4
Fair Value Of Derivative Liability [1] 61.6 55.8
Not Designated as Hedging Instrument [Member] | Gas Utility [Member] | Spire Missouri [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above [2] 2.9 3.4
Fair Value Of Derivative Liability [2] 25.9 13.6
Not Designated as Hedging Instrument [Member] | N Y M E X Natural Gas Contracts [Member] | Accounts Receivable Other [Member] | Gas Utility [Member] | Spire Missouri [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above [2] 2.9 3.4
Fair Value Of Derivative Liability [2] 25.9 13.6
Not Designated as Hedging Instrument [Member] | N Y M E X Natural Gas Contracts [Member] | Accounts Receivable Other [Member] | Operating Segments [Member] | Gas Utility [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 2.9 3.4
Fair Value Of Derivative Liability [1] 25.9 13.6
Not Designated as Hedging Instrument [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Derivative Instruments Liability [Member] | Operating Segments [Member] | Gas Marketing [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 11.3 6.2
Fair Value Of Derivative Liability [1] 17.7 13.7
Not Designated as Hedging Instrument [Member] | N Y M E X And I C E Natural Gas Contracts [Member] | Other Deferred Charges [Member] | Operating Segments [Member] | Gas Marketing [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 0.1 0.8
Fair Value Of Derivative Liability [1] 1.3 4.0
Not Designated as Hedging Instrument [Member] | Gasoline And Heating Oil Contracts [Member] | Accounts Receivable Other [Member] | Gas Utility [Member] | Spire Missouri [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above [2]   0.0
Not Designated as Hedging Instrument [Member] | Gasoline And Heating Oil Contracts [Member] | Accounts Receivable Other [Member] | Operating Segments [Member] | Gas Utility [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above   0.0
Fair Value Of Derivative Liability  
Not Designated as Hedging Instrument [Member] | Natural Gas Commodity Contracts [Member] | Derivative Instruments Assets [Member] | Operating Segments [Member] | Gas Marketing [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 42.8 42.1
Fair Value Of Derivative Liability [1] 15.6 19.8
Not Designated as Hedging Instrument [Member] | Natural Gas Commodity Contracts [Member] | Other Deferred Charges [Member] | Operating Segments [Member] | Gas Marketing [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above 2.0 3.9
Fair Value Of Derivative Liability [1] $ 1.1 $ 4.7
[1] The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of the Company’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.
[2] The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of Spire Missouri’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.
v3.25.3
Derivative Instruments and Hedging Activities - Reconciliation of Amounts in the Consolidated Balance Sheets (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above $ 69.1 $ 57.2
Fair value of cash margin receivable offset with derivatives 6.0 11.1
Netting of assets and liabilities with the same counterparty (23.0) (25.0)
Total 52.1 43.3
Current Assets: Other 50.1 39.5
Deferred Charges and Other Assets: Other 2.0 3.8
Fair value of derivative liabilities presented above [1] 61.6 57.3
Netting of assets and liabilities with the same counterparty (23.0) (25.0)
Total 38.6 32.3
Current Liabilities: Other 37.5 27.6
Deferred Credits and Other Liabilities: Other $ 1.1 $ 4.7
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] Other Assets, Current Other Assets, Current
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] Regulatory and Other Assets, Noncurrent Regulatory and Other Assets, Noncurrent
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Liabilities Current Other Liabilities Current
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Liabilities, Other than Long-Term Debt, Noncurrent Liabilities, Other than Long-Term Debt, Noncurrent
Spire Missouri [Member]    
Derivatives, Fair Value [Line Items]    
Fair value of derivative assets presented above $ 2.9 $ 3.4
Netting of assets and liabilities with the same counterparty (1.3) (3.8)
Total 0.0 0.0
Fair value of derivative liabilities presented above 25.9 13.6
Netting of assets and liabilities with the same counterparty (1.3) (3.8)
Total 24.6 9.8
Current Liabilities: Other 24.6 9.8
Deferred Credits and Other Liabilities: Other 0.0 0.0
Fair value of cash margin receivable offset with derivatives $ (1.6) $ 0.4
[1] The fair values of Derivative Assets and Derivative Liabilities exclude the fair value of cash margin receivables or payables with counterparties subject to netting arrangements. Fair value amounts of derivative contracts (including the fair value amounts of cash margin receivables and payables) for which there is a legal right to set off are presented net on the balance sheets. As such, the gross balances presented in the table above are not indicative of the Company’s net economic exposure. Refer to Note 9, Fair Value Measurements, for information on the valuation of derivative instruments.
v3.25.3
Concentrations of Credit Risk - Additional Information (Details)
Pures in Millions, $ in Millions
 12 Months Ended
Sep. 30, 2025
USD ($)
Customer Concentration Risk [Member] | Utility Companies and Their Marketing Affiliates [Member]  
Concentration Risk [Line Items]  
Accounts Receivable, after Allowance for Credit Loss $ 52.3
Customer Concentration Risk [Member] | Five Largest Counterparties [Member]  
Concentration Risk [Line Items]  
Accounts Receivable, after Allowance for Credit Loss $ 25.6
Gas Utility [Member]  
Concentration Risk [Line Items]  
Number of Customer Serves | Pures 1.7
v3.25.3
Income Taxes - Additional Information (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Income Tax Contingency [Line Items]    
Unrecognized tax benefits that would impact effective tax rate $ 2.7 $ 6.2
Unrecognized tax benefits, interest accrued 0.0 0.0
Spire Missouri [Member]    
Income Tax Contingency [Line Items]    
Unrecognized tax benefits that would impact effective tax rate 1.3 5.3
Spire Alabama Inc [Member]    
Income Tax Contingency [Line Items]    
Unrecognized tax benefits that would impact effective tax rate $ 0.3 $ 0.3
v3.25.3
Income Taxes - Provision for Income Taxes (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
State and local Tax Expense (Benefit) [Abstract]      
Total income tax expense $ 59.7 $ 58.7 $ 38.8
Spire Missouri [Member]      
Federal Tax Expense (Benefit) [Abstract]      
Current 0.0 0.0 0.0
Deferred 12.4 13.5 10.1
Investment tax credits (0.2) (0.2) (0.2)
State and local Tax Expense (Benefit) [Abstract]      
Current 0.2 0.9 0.0
Deferred 1.4 1.5 1.7
Total income tax expense 13.8 15.7 11.6
Spire Alabama Inc [Member]      
Federal Tax Expense (Benefit) [Abstract]      
Current 0.0 0.0 0.0
Deferred 22.9 21.7 15.8
Investment tax credits 0.0 0.0 0.0
State and local Tax Expense (Benefit) [Abstract]      
Current 0.0 0.0 0.0
Deferred 5.5 5.2 4.5
Total income tax expense 28.4 26.9 20.3
Parent Company [Member]      
Federal Tax Expense (Benefit) [Abstract]      
Current 1.7 0.2 0.7
Deferred 46.3 46.1 30.4
Investment tax credits (0.2) (0.2) (0.2)
State and local Tax Expense (Benefit) [Abstract]      
Current 0.7 1.5 1.2
Deferred 11.2 11.1 6.7
Total income tax expense $ 59.7 $ 58.7 $ 38.8
v3.25.3
Income Taxes - Effective Income Tax Rate (Details)
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Spire Missouri [Member]      
Effective Income Tax Rate Reconciliation [Line Items]      
Federal income tax statutory rate 21.00% 21.00% 21.00%
State and local income taxes, net of federal income tax benefits 2.60% 2.60% 2.60%
Certain expenses capitalized on books and deducted on tax return (2.50%) (2.70%) (2.70%)
Tax credits [1] (1.10%) (1.10%) (4.20%)
Amortization of excess deferred taxes (7.00%) (7.40%) (7.70%)
Taxes related to prior years (2.90%) 0.00% 0.00%
Other items - net (0.40%) (0.70%) 0.00%
Effective income tax rate 9.70% 11.70% 9.00%
Spire Alabama Inc [Member]      
Effective Income Tax Rate Reconciliation [Line Items]      
Federal income tax statutory rate 21.00% 21.00% 21.00%
State and local income taxes, net of federal income tax benefits 4.10% 4.10% 4.10%
Certain expenses capitalized on books and deducted on tax return 0.00% 0.00% 0.00%
Tax credits [1] (0.30%) (0.30%) (1.90%)
Amortization of excess deferred taxes 0.10% 0.20% 0.20%
Taxes related to prior years 0.00% 0.00% 0.00%
Other items - net 0.10% 0.10% 0.10%
Effective income tax rate 25.00% 25.10% 23.50%
Parent Company [Member]      
Effective Income Tax Rate Reconciliation [Line Items]      
Federal income tax statutory rate 21.00% 21.00% 21.00%
State and local income taxes, net of federal income tax benefits 3.70% 3.70% 3.70%
Certain expenses capitalized on books and deducted on tax return (1.10%) (1.20%) (1.40%)
Tax credits [1] (0.80%) (0.90%) (3.30%)
Amortization of excess deferred taxes (3.10%) (3.30%) (5.10%)
Taxes related to prior years (1.30%) 0.00% 0.00%
Other items - net (0.40%) (0.30%) 0.20%
Effective income tax rate 18.00% 19.00% 15.10%
[1] In 2023, the Company completed a research and development study which encompassed fiscal years 2014 to 2022.
v3.25.3
Income Taxes - Significant Items Comprising the Net Deferred Tax Liability or Asset (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Spire Missouri [Member]    
Deferred tax assets:    
Operating losses $ 1.5 $ 24.7
Goodwill 0.0 0.0
Pension and other postretirement benefits 36.0 39.3
Regulatory amount due to customers, net 21.4 24.5
Reserves not currently deductible 0.0 0.0
Other 16.7 12.3
Total deferred tax assets 75.6 100.8
Deferred tax liabilities:    
Relating to property (572.6) (531.2)
Regulatory pension and other postretirement benefits (27.2) (33.8)
Deferred gas costs (8.2) (17.7)
Other [1] (66.3) (85.7)
Total deferred tax liabilities (674.3) (668.4)
Net deferred tax (liability) asset (598.7) (567.6)
Spire Alabama Inc [Member]    
Deferred tax assets:    
Operating losses 146.1 153.0
Goodwill 29.7 44.4
Pension and other postretirement benefits 14.8 17.1
Regulatory amount due to customers, net 0.0 2.3
Reserves not currently deductible 3.4 2.9
Other 6.0 2.1
Total deferred tax assets 200.0 221.8
Deferred tax liabilities:    
Relating to property (238.1) (230.0)
Regulatory pension and other postretirement benefits (24.0) (25.6)
Deferred gas costs 0.0 0.0
Other [1] (2.0) (2.1)
Total deferred tax liabilities (264.1) (257.7)
Net deferred tax (liability) asset (64.1) (35.9)
Parent Company [Member]    
Deferred tax assets:    
Operating losses 150.1 182.2
Goodwill 0.0 0.0
Pension and other postretirement benefits 52.6 58.6
Regulatory amount due to customers, net 23.9 27.1
Reserves not currently deductible 24.9 0.5
Other 73.5 43.3
Total deferred tax assets 325.0 311.7
Deferred tax liabilities:    
Relating to property (912.3) (842.2)
Regulatory pension and other postretirement benefits (54.4) (60.8)
Deferred gas costs (10.7) (19.9)
Other [1] (235.0) (197.2)
Total deferred tax liabilities (1,212.4) (1,120.1)
Net deferred tax (liability) asset $ (887.4) $ (808.4)
[1] For Spire, Other consists primarily of goodwill-related liabilities.
v3.25.3
Income Taxes - Summary of Federal and State Loss and Contribution and Tax Credit Carryforwards (Details)
$ in Millions
Sep. 30, 2025
USD ($)
Tax Credit Carryforward [Line Items]  
Federal and state loss carryforwards $ 646.1
Tax credit carryforwards 18.9
Spire Missouri [Member]  
Tax Credit Carryforward [Line Items]  
Federal and state loss carryforwards 9.7
Tax credit carryforwards 8.8
Spire Alabama Inc [Member]  
Tax Credit Carryforward [Line Items]  
Federal and state loss carryforwards 583.3
Tax credit carryforwards $ 2.7
v3.25.3
Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Spire Missouri [Member]      
Income Tax Contingency [Line Items]      
Unrecognized tax benefits, beginning of year $ 25.3 $ 22.9 $ 19.3
Increases related to tax positions taken in current year 0.2 2.4 3.6
Decreases related to tax positions taken in prior years 24.2 0.0 0.0
Reductions due to lapse of applicable statute of limitations 0.0 0.0 0.0
Unrecognized tax benefits, end of year 1.3 25.3 22.9
Spire Alabama Inc [Member]      
Income Tax Contingency [Line Items]      
Unrecognized tax benefits, beginning of year 0.3 0.3 0.0
Increases related to tax positions taken in current year 0.0 0.0 0.3
Decreases related to tax positions taken in prior years 0.0 0.0 0.0
Reductions due to lapse of applicable statute of limitations 0.0 0.0 0.0
Unrecognized tax benefits, end of year 0.3 0.3 0.3
Parent Company [Member]      
Income Tax Contingency [Line Items]      
Unrecognized tax benefits, beginning of year 26.3 23.8 19.6
Increases related to tax positions taken in current year 0.6 2.6 4.2
Decreases related to tax positions taken in prior years (24.2) 0.0 0.0
Reductions due to lapse of applicable statute of limitations 0.0 (0.1) 0.0
Unrecognized tax benefits, end of year $ 2.7 $ 26.3 $ 23.8
v3.25.3
Pension Plans and Other Postretirement Benefits - Additional Information (Details)
 12 Months Ended
Dec. 26, 2022
USD ($)
Dec. 25, 2022
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Sep. 30, 2023
USD ($)
Dec. 26, 2021
USD ($)
Dec. 25, 2021
USD ($)
Dec. 23, 2021
USD ($)
Regulatory Asset, Total     $ 1,401,800,000 $ 1,367,200,000        
Defined benefit plan, benefit obligation, actuarial losses prior years, percent     0.0040          
Defined benefit plan, benefit obligation, actuarial gains from prior years, percent     0.45%          
Implementation Period Used To Calculate Return On Plan Assets (Year)     4 years          
Gains Or Losses Includible In Cost Amortized To Extent Exceeds Projected Benefit Obligations or Market Related Value of Plan Assets Percentage     10.00%          
Regulatory Liability     $ 617,400,000 585,000,000        
Defined Contribution Plan, Cost     16,500,000 16,600,000 $ 15,500,000      
Pension Plan [Member]                
Defined Benefit Plan, Plan Assets, Contributions by Employer     75,800,000 38,500,000        
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits     0 2,600,000 0      
Other Postretirement Benefits Plan [Member]                
Defined Benefit Plan, Plan Assets, Contributions by Employer     2,700,000 200,000        
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits     $ 0 $ 6,100,000 $ 0      
Spire Missouri [Member]                
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate     5.55% 5.10% 6.25%      
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement     $ 1,500,000 $ 37,300,000        
Regulatory Asset, Total     702,100,000 672,000,000        
Regulatory Liability     495,200,000 453,500,000        
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits       6,100,000        
Defined Contribution Plan, Cost     9,300,000 9,300,000 $ 9,100,000      
Spire Missouri [Member] | Pension Costs [Member] | Missouri West [Member]                
Regulatory Asset, Total           $ 4,400,000 $ 5,500,000  
Spire Missouri [Member] | Pension Costs [Member] | Missouri East [Member]                
Regulatory Asset, Total           $ 29,900,000 $ 32,400,000  
Spire Missouri [Member] | Pension and Other Postretirement Plans Costs [Member] | Missouri West [Member]                
Regulatory Liabilities For Which No Return On Investment During Recovery Period Is Provided $ 800,000 $ 1,100,000            
Remaining Recovery Period of Regulatory Liabilities for which No Return on Investment During Recovery Period is Provided (Year) 8 years 8 years            
Spire Missouri [Member] | Pension and Other Postretirement Plans Costs [Member] | Missouri East [Member]                
Regulatory Assets for Which No Return on Investment During Recovery Period Is Provided $ 6,900,000 $ 11,000,000            
Remaining recovery period of regulatory assets for which no return on investment during recovery period is provided (Year)   8 years            
Additional Remaining Recovery Period of Regulatory Assets for Which No Return on Investment During Recovery Period Is Provided (Year) 8 years              
Spire Missouri [Member] | Pension Plan [Member]                
Defined Benefit Plan, Plan Assets, Contributions by Employer     37,200,000 25,400,000        
Anticipated Contributions to Pension Plans Qualified Trusts     22,100,000          
Anticipated Contributions To Pension Plans Non Qualified Trusts     600,000          
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits     0 2,600,000 0      
Spire Missouri [Member] | Pension Plan [Member] | Nonqualified Plan [Member]                
Defined Benefit Plan, Plan Assets, Contributions by Employer     0          
Spire Missouri [Member] | Other Postretirement Benefits Plan [Member]                
Defined Benefit Plan, Plan Assets, Contributions by Employer     2,700,000 200,000        
Postretirement Benefit Plans, Recovery in Rates Base Allowance               $ 8,600,000
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits     0 6,100,000 0      
Spire Missouri [Member] | Other Postretirement Benefits Plan [Member] | Missouri West [Member]                
Regulatory Liability $ 100,000              
Spire Missouri [Member] | Other Postretirement Benefits Plan [Member] | Missouri East [Member]                
Regulatory Liability $ 900,000              
Spire Alabama Inc [Member]                
Regulatory Asset, Total     666,700,000 661,200,000        
Regulatory Liability     49,500,000 62,100,000        
Defined Contribution Plan, Cost     $ 3,000,000 $ 2,900,000 3,100,000      
Spire Alabama Inc [Member] | Pension Plan [Member]                
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate     5.55% 5.10%        
Defined Benefit Plan, Plan Assets, Contributions by Employer     $ 30,100,000 $ 12,600,000        
Anticipated Contributions to Pension Plans Qualified Trusts     7,000,000          
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits     $ 0 0 0      
Spire Alabama Inc [Member] | Other Postretirement Benefits Plan [Member]                
Anticipated Contributions to Pension Plans Qualified Trusts       0        
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits       $ 0 $ 0      
Spire Alabama And Spire Missouri [Member] | Other Postretirement Benefits Plan [Member]                
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate     5.50% 5.05%        
v3.25.3
Pension Plans and Other Postretirement Benefits - Net Pension Costs (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Spire Missouri [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Special termination benefits   $ 6.1  
Pension Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost - benefits earned during the period $ 17.6 15.7 $ 16.3
Interest cost on projected benefit obligation 23.5 26.7 25.1
Expected return on plan assets (25.9) (24.8) (24.5)
Amortization of prior service credit (4.5) (4.5) (4.5)
Amortization of actuarial loss 6.5 6.4 6.6
Loss on lump-sum settlements and curtailments 0.4 12.9 9.7
Subtotal 17.6 35.0 28.7
Regulatory adjustment 36.3 18.4 26.3
Net pension cost 53.9 53.4 55.0
Special termination benefits 0.0 2.6 0.0
Pension Plan [Member] | Spire Missouri [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost - benefits earned during the period 11.4 10.4 11.4
Interest cost on projected benefit obligation 15.8 18.9 17.8
Expected return on plan assets (17.6) (17.0) (18.0)
Amortization of prior service credit (1.9) (1.9) (1.9)
Amortization of actuarial loss 4.1 5.9 6.1
Loss on lump-sum settlements and curtailments 0.4 12.9 0.6
Subtotal 12.2 31.8 16.0
Regulatory adjustment 29.6 10.8 27.1
Net pension cost 41.8 42.6 43.1
Special termination benefits 0.0 2.6 0.0
Pension Plan [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost - benefits earned during the period 5.5 4.6 4.2
Interest cost on projected benefit obligation 5.1 5.1 4.8
Expected return on plan assets (5.3) (4.8) (3.5)
Amortization of prior service credit (2.4) (2.4) (2.4)
Amortization of actuarial loss 2.4 1.0 0.9
Loss on lump-sum settlements and curtailments 0.0 0.0 9.1
Subtotal 5.3 3.5 13.1
Regulatory adjustment 5.8 6.7 (1.7)
Net pension cost 11.1 10.2 11.4
Special termination benefits 0.0 0.0 0.0
Other Postretirement Benefits Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost - benefits earned during the period 4.2 4.3 4.8
Interest cost on projected benefit obligation 7.3 8.9 8.5
Expected return on plan assets (16.9) (16.0) (15.8)
Amortization of prior service credit 0.2 0.3 0.3
Amortization of actuarial loss (5.8) (5.8) (4.0)
Subtotal (11.0) (2.2) (6.2)
Regulatory adjustment 4.5 (3.6) 0.6
Net pension cost (6.5) (5.8) (5.6)
Special termination benefits 0.0 6.1 0.0
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost - benefits earned during the period 3.5 3.5 4.0
Interest cost on projected benefit obligation 5.2 6.6 6.5
Expected return on plan assets (11.1) (10.6) (10.5)
Amortization of prior service credit 0.3 0.6 0.6
Amortization of actuarial loss (5.1) (5.2) (3.2)
Subtotal (7.2) 1.0 (2.6)
Regulatory adjustment 6.2 (1.9) 1.8
Net pension cost (1.0) (0.9) (0.8)
Special termination benefits 0.0 6.1 0.0
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost - benefits earned during the period 0.7 0.7 0.7
Interest cost on projected benefit obligation 2.0 2.1 1.8
Expected return on plan assets (5.4) (5.1) (5.0)
Amortization of prior service credit (0.1) (0.3) (0.3)
Amortization of actuarial loss (0.1) (0.1) (0.5)
Subtotal (2.9) (2.7) (3.3)
Regulatory adjustment (1.8) (1.8) (1.3)
Net pension cost $ (4.7) (4.5) (4.6)
Special termination benefits   $ 0.0 $ 0.0
v3.25.3
Pension Plans and Other Postretirement Benefits - Other Changes in Plan Assets and Pension Benefit Obligations (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Pension Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Current year actuarial (gain) loss $ (11.9) $ 8.8 $ 14.5
Amortization of actuarial loss (6.5) (6.4) (6.6)
Acceleration of loss recognized due to settlement (0.4) (12.9) (9.7)
Current year service credit 0.0 0.2 0.0
Amortization of prior service credit 4.5 4.5 4.5
Subtotal (14.3) (5.8) 2.7
Regulatory adjustment 13.0 5.2 (2.8)
Total recognized in OCI (1.3) (0.6) (0.1)
Pension Plan [Member] | Spire Missouri [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Current year actuarial (gain) loss (9.9) (0.9) 5.7
Amortization of actuarial loss (4.1) (5.9) (6.1)
Acceleration of loss recognized due to settlement (0.4) (12.9) (0.6)
Current year service credit 0.0 0.2 0.0
Amortization of prior service credit 1.9 1.9 1.9
Subtotal (12.5) (17.6) 0.9
Regulatory adjustment 11.2 17.0 (1.0)
Total recognized in OCI (1.3) (0.6) (0.1)
Pension Plan [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Current year actuarial (gain) loss (0.8) 8.5 9.0
Amortization of actuarial loss (2.4) (1.0) (0.9)
Acceleration of loss recognized due to settlement 0.0 0.0 (9.1)
Current year service credit 0.0 0.0 0.0
Amortization of prior service credit 2.4 2.4 2.4
Subtotal (0.8) 9.9 1.4
Regulatory adjustment 0.8 (9.9) (1.4)
Total recognized in OCI 0.0 0.0 0.0
Other Postretirement Benefits Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Current year actuarial (gain) loss (36.5) (52.4) (24.4)
Amortization of actuarial loss 5.8 5.8 4.0
Amortization of prior service credit (0.2) (0.3) (0.3)
Subtotal (30.9) (51.6) (20.7)
Regulatory adjustment 30.9 51.6 20.7
Total recognized in OCI 0.0 0.0 0.0
Current year prior service cost 0.0 (4.7) 0.0
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Current year actuarial (gain) loss (31.9) (40.4) (21.5)
Amortization of actuarial loss 5.1 5.2 3.2
Amortization of prior service credit (0.3) (0.6) (0.6)
Subtotal (27.1) (40.5) (18.9)
Regulatory adjustment 27.1 40.5 18.9
Total recognized in OCI 0.0 0.0 0.0
Current year prior service cost   (4.7) 0.0
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Current year actuarial (gain) loss (4.0) (9.3) (1.1)
Amortization of actuarial loss 0.1 0.1 0.5
Amortization of prior service credit 0.1 0.3 0.3
Subtotal (3.8) (8.9) (0.3)
Regulatory adjustment 3.8 8.9 0.3
Total recognized in OCI $ 0.0 0.0 0.0
Current year prior service cost   $ 0.0 $ 0.0
v3.25.3
Pension Plans and Other Postretirement Benefits - Reconciliation of Pension Benefit Obligation (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Spire Missouri [Member]      
Special termination benefits   $ 6.1  
Pension Plan [Member]      
Benefit obligation, beginning of year $ 469.7 438.7  
Service cost – benefits earned during the period 17.6 15.7 $ 16.3
Interest cost on projected benefit obligation 23.5 26.7 25.1
Actuarial loss (gain) (15.3) 46.0  
Plan amendments 0.0 0.2  
Special termination benefits 0.0 2.6  
Settlement benefits paid (1.5) (37.3)  
Regular benefits paid (43.8) (22.9)  
Benefit obligation, end of year 450.2 469.7 438.7
Accumulated benefit obligation, end of year 439.6 459.4  
Special termination benefits 0.0 2.6 0.0
Pension Plan [Member] | Spire Missouri [Member]      
Benefit obligation, beginning of year 319.7 313.2  
Service cost – benefits earned during the period 11.4 10.4 11.4
Interest cost on projected benefit obligation 15.8 18.9 17.8
Actuarial loss (gain) (8.5) 25.2  
Plan amendments 0.0 0.2  
Special termination benefits 0.0 2.6  
Settlement benefits paid (1.5) (37.3)  
Regular benefits paid (29.7) (13.5)  
Benefit obligation, end of year 307.2 319.7 313.2
Accumulated benefit obligation, end of year 302.8 314.7  
Special termination benefits 0.0 2.6 0.0
Pension Plan [Member] | Spire Alabama Inc [Member]      
Benefit obligation, beginning of year 97.9 80.6  
Service cost – benefits earned during the period 5.5 4.6 4.2
Interest cost on projected benefit obligation 5.1 5.1 4.8
Actuarial loss (gain) (4.3) 14.3  
Plan amendments 0.0 0.0  
Special termination benefits 0.0 0.0  
Settlement benefits paid 0.0 0.0  
Regular benefits paid (11.2) (6.7)  
Benefit obligation, end of year 93.0 97.9 80.6
Accumulated benefit obligation, end of year 87.3 92.9  
Special termination benefits 0.0 0.0 0.0
Other Postretirement Benefits Plan [Member]      
Benefit obligation, beginning of year 142.5 142.6  
Service cost – benefits earned during the period 4.2 4.3 4.8
Interest cost on projected benefit obligation 7.3 8.9 8.5
Actuarial loss (gain) (18.4) (1.5)  
Plan amendments 0.0 (4.7)  
Regular benefits paid (4.1) (13.4)  
Benefit obligation, end of year 131.5 142.5 142.6
Retiree drug subsidy program 0.0 0.2  
Special termination benefits 0.0 6.1 0.0
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]      
Benefit obligation, beginning of year 102.4 105.3  
Service cost – benefits earned during the period 3.5 3.5 4.0
Interest cost on projected benefit obligation 5.2 6.6 6.5
Actuarial loss (gain) (17.1) (3.2)  
Plan amendments 0.0 (4.7)  
Regular benefits paid (1.9) (11.4)  
Benefit obligation, end of year 92.1 102.4 105.3
Retiree drug subsidy program 0.0 0.2  
Special termination benefits 0.0 6.1 0.0
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]      
Benefit obligation, beginning of year 39.0 35.1  
Service cost – benefits earned during the period 0.7 0.7 0.7
Interest cost on projected benefit obligation 2.0 2.1 1.8
Actuarial loss (gain) (1.2) 3.1  
Regular benefits paid (2.2) (2.0)  
Benefit obligation, end of year $ 38.3 39.0 35.1
Special termination benefits   $ 0.0 $ 0.0
v3.25.3
Pension Plans and Other Postretirement Benefits - Reconciliation of Fair Value of Plan Assets (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Pension Plan [Member]    
Fair value of plan assets, beginning of year $ 374.8 $ 334.7
Actual return on plan assets 22.4 61.8
Employer contributions 75.8 38.5
Settlement benefits paid (1.5) (37.3)
Regular benefits paid (43.8) (22.9)
Fair value of plan assets, end of year 427.7 374.8
Funded status of plans, end of year (22.5) (94.9)
Pension Plan [Member] | Spire Missouri [Member]    
Fair value of plan assets, beginning of year 259.8 242.0
Actual return on plan assets 19.0 43.2
Employer contributions 37.2 25.4
Settlement benefits paid (1.5) (37.3)
Regular benefits paid (29.7) (13.5)
Fair value of plan assets, end of year 284.8 259.8
Funded status of plans, end of year (22.4) (59.9)
Pension Plan [Member] | Spire Alabama Inc [Member]    
Fair value of plan assets, beginning of year 69.9 53.6
Actual return on plan assets 1.8 10.4
Employer contributions 30.1 12.6
Settlement benefits paid 0.0 0.0
Regular benefits paid (11.2) (6.7)
Fair value of plan assets, end of year 90.6 69.9
Funded status of plans, end of year (2.4) (28.0)
Other Postretirement Benefits Plan [Member]    
Fair value of plan assets, beginning of year 339.4 286.3
Actual return on plan assets 34.9 66.3
Employer contributions 2.7 0.2
Regular benefits paid (4.1) (13.4)
Fair value of plan assets, end of year 372.9 339.4
Funded status of plans, end of year 241.4 196.9
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]    
Fair value of plan assets, beginning of year 224.9 188.8
Actual return on plan assets 25.7 47.3
Employer contributions 2.7 0.2
Regular benefits paid (1.9) (11.4)
Fair value of plan assets, end of year 251.4 224.9
Funded status of plans, end of year 159.3 122.5
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]    
Fair value of plan assets, beginning of year 107.5 92.0
Actual return on plan assets 8.2 17.5
Regular benefits paid (2.2) (2.0)
Fair value of plan assets, end of year 113.5 107.5
Funded status of plans, end of year $ 75.2 $ 68.5
v3.25.3
Pension Plans and Other Postretirement Benefits - Amounts Recognized in the Balance Sheets (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Noncurrent liabilities $ (74.7) $ (146.7)
Spire Missouri [Member]    
Noncurrent liabilities (72.4) (110.0)
Spire Alabama Inc [Member]    
Noncurrent liabilities (2.4) (28.0)
Pension Plan [Member]    
Noncurrent assets 6.2 0.0
Current liabilities (0.6) (1.0)
Noncurrent liabilities (28.1) (93.9)
Total (22.5) (94.9)
Pension Plan [Member] | Spire Missouri [Member]    
Noncurrent assets 3.9 0.0
Current liabilities (0.6) (1.0)
Noncurrent liabilities (25.7) (58.9)
Total (22.4) (59.9)
Pension Plan [Member] | Spire Alabama Inc [Member]    
Noncurrent assets 0.0 0.0
Current liabilities 0.0 0.0
Noncurrent liabilities (2.4) (28.0)
Total (2.4) (28.0)
Other Postretirement Benefits Plan [Member]    
Noncurrent assets 288.2 248.3
Current liabilities (0.4) (0.4)
Noncurrent liabilities (46.4) (51.0)
Total 241.4 196.9
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]    
Noncurrent assets 206.1 173.9
Current liabilities (0.4) (0.4)
Noncurrent liabilities (46.4) (51.0)
Total 159.3 122.5
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]    
Noncurrent assets 75.2 68.5
Current liabilities 0.0 0.0
Noncurrent liabilities 0.0 0.0
Total $ 75.2 $ 68.5
v3.25.3
Pension Plans and Other Postretirement Benefits - Amounts Recognized in AOCI Not Yet Recognized As Components of Net Periodic Pension Costs (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Pension Plan [Member]    
Net actuarial loss $ 100.9 $ 119.7
Prior service credit (22.0) (26.4)
Subtotal 78.9 93.3
Adjustments for amounts included in regulatory assets (77.8) (90.8)
Total 1.1 2.5
Pension Plan [Member] | Spire Missouri [Member]    
Net actuarial loss 58.5 72.9
Prior service credit (12.1) (14.0)
Subtotal 46.4 58.9
Adjustments for amounts included in regulatory assets (45.3) (56.4)
Total 1.1 2.5
Pension Plan [Member] | Spire Alabama Inc [Member]    
Net actuarial loss 44.5 47.7
Prior service credit (9.1) (11.5)
Subtotal 35.4 36.2
Adjustments for amounts included in regulatory assets (35.4) (36.2)
Total 0.0 0.0
Other Postretirement Benefits Plan [Member]    
Net actuarial loss (180.6) (150.0)
Prior service credit 2.0 2.0
Subtotal (178.6) (148.0)
Adjustments for amounts included in regulatory assets 178.6 148.0
Total 0.0 0.0
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]    
Net actuarial loss (154.2) (127.5)
Prior service credit 2.0 2.1
Subtotal (152.2) (125.4)
Adjustments for amounts included in regulatory assets 152.2 125.4
Total 0.0 0.0
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]    
Net actuarial loss (19.3) (15.4)
Prior service credit 0.0 (0.1)
Subtotal (19.3) (15.5)
Adjustments for amounts included in regulatory assets 19.3 15.5
Total $ 0.0 $ 0.0
v3.25.3
Pension Plans and Other Postretirement Benefits - Assumption Used (Details)
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Pension Plan [Member]      
Weighted average rate of future compensation increase (all plans) 3.50% 3.50%  
Spire Alabama Inc [Member] | Pension Plan [Member]      
Weighted average discount rate 5.10%    
Weighted average rate of future compensation increase 3.50% 3.00% 3.00%
Expected long-term rate of return on plan assets 6.75% 6.75% 6.50%
Weighted average discount rate 5.55% 5.10%  
Spire Alabama Inc [Member] | Pension Plan [Member] | Minimum [Member]      
Weighted average discount rate   6.20% 5.65%
Spire Alabama Inc [Member] | Pension Plan [Member] | Maximum [Member]      
Weighted average discount rate   6.25% 5.70%
Spire Alabama Inc [Member] | Other Postretirement Benefits Plan [Member]      
Weighted average discount rate 5.05% 6.30% 5.80%
Spire Alabama Inc [Member] | Other Postretirement Benefits Plan [Member] | Minimum [Member]      
Expected long-term rate of return on plan assets 4.75% 4.75% 4.75%
Spire Alabama Inc [Member] | Other Postretirement Benefits Plan [Member] | Maximum [Member]      
Expected long-term rate of return on plan assets 6.00% 6.00% 6.00%
Spire Missouri East [Member] | Pension Plan [Member]      
Weighted average discount rate 5.10% 6.25% 5.70%
Weighted average discount rate 5.55% 5.10%  
Spire Missouri [Member]      
Weighted average discount rate 5.55% 5.10% 6.25%
Spire Missouri [Member] | Pension Plan [Member]      
Weighted average rate of future compensation increase 3.50% 3.00% 3.00%
Expected long-term rate of return on plan assets 6.50% 6.50% 6.50%
Spire Missouri [Member] | Other Postretirement Benefits Plan [Member]      
Weighted average discount rate 5.05% 6.30% 5.80%
Expected long-term rate of return on plan assets 5.50% 5.50% 5.50%
Spire Missouri West [Member] | Pension Plan [Member]      
Weighted average discount rate 5.05% 6.30% 5.80%
Weighted average discount rate 5.45% 5.05%  
Spire Alabama or Spire Missouri [Member] | Pension Plan [Member]      
Cash balance interest crediting rate - Spire Alabama / Spire Missouri 4.25% 4.25%  
v3.25.3
Pension Plans and Other Postretirement Benefits - PBO, ABO, and Fair Value of Plan Assets for Plans in Excess of Plan Assets (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Projected benefit obligation $ 450.2 $ 469.7
Accumulated benefit obligation 439.6 459.4
Fair value of plan assets 427.7 374.8
Spire Missouri [Member]    
Projected benefit obligation 307.2 319.7
Accumulated benefit obligation 302.8 314.7
Fair value of plan assets 284.8 259.8
Spire Alabama Inc [Member]    
Projected benefit obligation 93.0 97.9
Accumulated benefit obligation 87.3 92.9
Fair value of plan assets $ 90.6 $ 69.9
v3.25.3
Pension Plans and Other Postretirement Benefits - Targeted and Actual Plan Assets by Category (Details)
Sep. 30, 2025
Sep. 30, 2024
Pension Plan [Member] | Spire Missouri [Member]    
Return seeking assets, target 100.00% 100.00%
Return seeking assets, actual 100.00% 100.00%
Pension Plan [Member] | Spire Missouri [Member] | Return Seeking Assets [Member]    
Return seeking assets, target 70.00% 70.00%
Return seeking assets, actual 56.60% 71.30%
Pension Plan [Member] | Spire Missouri [Member] | Liability Hedging Assets [Member]    
Return seeking assets, target 30.00% 30.00%
Return seeking assets, actual 40.40% 24.30%
Pension Plan [Member] | Spire Missouri [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member]    
Return seeking assets, target 0.00% 0.00%
Return seeking assets, actual 3.00% 4.40%
Pension Plan [Member] | Spire Alabama Inc [Member]    
Return seeking assets, target 100.00% 100.00%
Return seeking assets, actual 100.00% 100.00%
Pension Plan [Member] | Spire Alabama Inc [Member] | Return Seeking Assets [Member]    
Return seeking assets, target 75.00% 75.00%
Return seeking assets, actual 72.00% 74.90%
Pension Plan [Member] | Spire Alabama Inc [Member] | Liability Hedging Assets [Member]    
Return seeking assets, target 25.00% 25.00%
Return seeking assets, actual 16.80% 22.60%
Pension Plan [Member] | Spire Alabama Inc [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member]    
Return seeking assets, target 0.00% 0.00%
Return seeking assets, actual 11.20% 2.50%
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]    
Return seeking assets, target 100.00%  
Return seeking assets, actual 100.00% 100.00%
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member] | Defined Benefit Plan, Equity Securities [Member]    
Return seeking assets, target 60.00%  
Return seeking assets, actual 58.60% 60.80%
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member] | Debt Securities [Member]    
Return seeking assets, target 40.00%  
Return seeking assets, actual 36.00% 38.20%
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member]    
Return seeking assets, target 0.00%  
Return seeking assets, actual 5.40% 1.00%
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]    
Return seeking assets, target 100.00%  
Return seeking assets, actual 100.00% 100.00%
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member] | Defined Benefit Plan, Equity Securities [Member]    
Return seeking assets, target 60.50%  
Return seeking assets, actual 60.90% 60.70%
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member] | Debt Securities [Member]    
Return seeking assets, target 39.50%  
Return seeking assets, actual 39.10% 39.30%
v3.25.3
Pension Plans and Other Postretirement Benefits - Expected Pension Benefit Payments for Succeeding Fiscal Years (Details)
$ in Millions
Sep. 30, 2025
USD ($)
Pension Plan [Member]  
2026 $ 51.2
2027 46.0
2028 45.3
2029 42.9
2030 41.7
2031-2035 196.2
Pension Plan [Member] | Spire Missouri [Member]  
2026 38.5
2027 33.4
2028 32.6
2029 30.5
2030 29.1
2031-2035 133.5
Pension Plan [Member] | Spire Alabama Inc [Member]  
2026 8.8
2027 8.8
2028 8.5
2029 8.4
2030 8.5
2031-2035 42.8
Other Postretirement Benefits Plan [Member]  
2026 13.4
2027 13.0
2028 12.5
2029 12.0
2030 11.6
2031-2035 54.0
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]  
2026 10.1
2027 9.7
2028 9.3
2029 8.9
2030 8.5
2031-2035 38.3
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]  
2026 3.2
2027 3.2
2028 3.1
2029 3.0
2030 3.0
2031-2035 $ 15.2
v3.25.3
Pension Plans and Other Postretirement Benefits - Assumed Medical Cost Trend Rates (Details) - Other Postretirement Benefits Plan [Member]
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Rate to which the medical cost trend rate is assumed to decline (the ultimate medical cost trend rate) 5.00% 5.00%
Year the rate reaches the ultimate trend 2034 2031
Spire Alabama And Spire Missouri [Member]    
Medical cost trend assumed for next year – Spire Alabama and Spire Missouri 7.00% 6.50%
v3.25.3
Pension Plans and Other Postretirement Benefits - Fair Value Measurements of Pension Plan Assets (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Pension Plan [Member]      
Defined Benefit Plan Assets $ 427.7 $ 374.8 $ 334.7
Pension Plan [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 284.8 259.8 242.0
Pension Plan [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 90.6 69.9 53.6
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 116.4 102.2  
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 75.4 73.3  
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 25.3 17.5  
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 311.3 272.6  
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 209.4 186.5  
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 65.3 52.4  
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 427.7 374.8  
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 284.8 259.8  
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 90.6 69.9  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 27.4 12.7  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 10.1 9.9  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 10.2 1.7  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 27.4 12.7  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 10.1 9.9  
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 10.2 1.7  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 181.5 152.4  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 117.1 102.2  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 41.3 30.6  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 181.5 152.4  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 117.1 102.2  
Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 41.3 30.6  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 61.4 57.7  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 43.1 40.2  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 11.7 10.6  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 61.4 57.7  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 43.1 40.2  
Pension Plan [Member] | Real Asset Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 11.7 10.6  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 50.7 55.6  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 35.1 38.2  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 9.9 10.6  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 50.7 55.6  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 35.1 38.2  
Pension Plan [Member] | U S Bond Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 9.9 10.6  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 38.3 33.9  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 30.2 25.2  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 5.2 5.2  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 38.3 33.9  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 30.2 25.2  
Pension Plan [Member] | U S Government Index Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 5.2 5.2  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 68.4 62.5  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 49.2 44.1  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 12.3 11.2  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 68.4 62.5  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 49.2 44.1  
Pension Plan [Member] | Global Funds Including U S [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 12.3 11.2  
Other Postretirement Benefits Plan [Member]      
Defined Benefit Plan Assets 372.9 339.4 286.3
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 251.4 224.9 188.8
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 113.5 107.5 $ 92.0
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 309.0 230.7  
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 251.4 224.9  
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 63.9 108.7  
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 372.9 339.4  
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 251.4 224.9  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 13.1 1.6  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 12.1 0.7  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 49.6 0.0  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 63.9 107.5  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 13.1 1.6  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 12.1 0.7  
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 113.5 107.5  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 294.5 229.1  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 239.3 224.2  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 49.6 0.0  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 44.4 89.0  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 44.4 89.0  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 338.9 318.1  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Missouri [Member]      
Defined Benefit Plan Assets 239.3 224.2  
Other Postretirement Benefits Plan [Member] | U S Stock Bond Mutual Fund [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 94.0 89.0  
Other Postretirement Benefits Plan [Member] | Debt Security, Corporate, Non-US [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan Assets 1.4 0.0  
Other Postretirement Benefits Plan [Member] | Debt Security, Corporate, Non-US [Member] | Fair Value, Inputs, Level 1 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 0.0 0.0  
Other Postretirement Benefits Plan [Member] | Debt Security, Corporate, Non-US [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan Assets 19.5 19.7  
Other Postretirement Benefits Plan [Member] | Debt Security, Corporate, Non-US [Member] | Fair Value, Inputs, Level 2 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets 19.5 18.5  
Other Postretirement Benefits Plan [Member] | Debt Security, Corporate, Non-US [Member] | Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Assets 20.9 19.7  
Other Postretirement Benefits Plan [Member] | Debt Security, Corporate, Non-US [Member] | Fair Value, Inputs, Level 3 [Member] | Spire Alabama Inc [Member]      
Defined Benefit Plan Assets $ 19.5 $ 18.5  
v3.25.3
Segment Information - Additional Information (Details)
 12 Months Ended
Sep. 30, 2025
Segment
Segment Reporting Information [Line Items]  
Number of reportable segments 3
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] srt:ChiefExecutiveOfficerMember
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description The CODM and management evaluate the performance of the segments based on the computation of adjusted earnings. Adjusted earnings excludes from reported net income, as applicable, the after-tax impacts of fair value accounting and timing adjustments associated with energy-related transactions, the impacts of acquisition, divestiture and restructuring activities, and the largely non-cash impacts of other non-recurring or unusual items such as certain regulatory, legislative or GAAP standard-setting actions. For each of the Company’s segments, the CODM uses adjusted earnings to allocate resources and determine reinvestment for each segment, predominantly in the annual budget and forecasting process. Adjusted earnings is also used to monitor budget versus actual results to assess performance of the segment and establish management compensation. The CODM does not receive asset information for the individual reportable segments.
Spire Missouri [Member]  
Segment Reporting Information [Line Items]  
Number of reportable segments 1
Spire Alabama Inc [Member]  
Segment Reporting Information [Line Items]  
Number of reportable segments 1
v3.25.3
Segment Information - Schedule of Financial Data Related to Gross Receipt Taxes and Capital Expenditures (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Property, Plant and Equipment [Line Items]      
Capital Expenditures $ 922.4 $ 861.3 $ 662.5
Spire Missouri [Member]      
Property, Plant and Equipment [Line Items]      
Gross Receipt Taxes 82.9 93.1 96.7
Capital Expenditures 641.2 553.0 447.5
Spire Alabama Inc [Member]      
Property, Plant and Equipment [Line Items]      
Gross Receipt Taxes 27.9 30.1 29.9
Capital Expenditures $ 144.2 $ 112.8 $ 117.6
v3.25.3
Segment Information - Schedule of Information about Segment Revenue, Segment Expenses and Adjusted Earnings (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disaggregation of Revenue [Line Items]      
Revenues from external customers $ 2,476.4 $ 2,593.0 $ 2,666.3
Intersegment revenues 0.0 0.0 0.0
Total Operating Revenues 2,476.4 2,593.0 2,666.3
Cost of gas sold, incl. gross receipts taxes 1,021.2 1,231.5 1,392.6
Operation and maintenance expense 542.1 507.4 517.6
Depreciation and amortization expense 298.2 278.4 254.8
Interest Expense 204.1 201.1 185.7
Income tax expense (benefit) 59.7 58.7 38.8
Other segment items [1] 75.6 68.5 48.7
Adjusted Earnings (Loss) 275.5 247.4 228.1
Capital expenditures 922.4 861.3 662.5
Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenues from external customers 2,473.9 2,592.3 2,665.6
Intersegment revenues 46.4 45.5 36.5
Total Operating Revenues 2,520.3 2,637.8 2,702.1
Cost of gas sold, incl. gross receipts taxes 1,067.6 1,276.9 1,429.1
Operation and maintenance expense 531.8 505.7 511.7
Depreciation and amortization expense 297.8 277.9 254.3
Interest Expense 148.7 154.3 148.5
Income tax expense (benefit) 74.2 68.4 49.3
Other segment items [1] 86.6 76.9 47.0
Adjusted Earnings (Loss) 313.6 277.7 262.2
Capital expenditures 923.7 862.5 662.6
Intersegment Eliminations [Member]      
Disaggregation of Revenue [Line Items]      
Revenues from external customers 0.0 0.0 0.0
Intersegment revenues (46.4) (45.5) (36.5)
Total Operating Revenues (46.4) (45.5) (36.5)
Cost of gas sold, incl. gross receipts taxes (46.4) (45.5) (36.5)
Operation and maintenance expense 0.0 0.0 0.0
Depreciation and amortization expense 0.0 0.0 0.0
Interest Expense 0.0 0.0 0.0
Income tax expense (benefit) 0.0 0.0 0.0
Other segment items [1] 0.0 0.0 0.0
Adjusted Earnings (Loss) 0.0 0.0 0.0
Capital expenditures 0.0 0.0 0.0
Gas Utility [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenues from external customers 2,207.5 2,436.2 2,456.6
Intersegment revenues 0.1 1.7 0.3
Total Operating Revenues 2,207.6 2,437.9 2,456.9
Cost of gas sold, incl. gross receipts taxes 970.9 1,238.7 1,321.1
Operation and maintenance expense 467.1 452.8 461.8
Depreciation and amortization expense 277.6 263.6 244.4
Interest Expense 137.1 147.3 139.9
Income tax expense (benefit) 47.4 48.0 32.7
Other segment items [1] 76.1 66.7 56.5
Adjusted Earnings (Loss) 231.4 220.8 200.5
Capital expenditures 816.8 691.1 588.6
Gas Marketing [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenues from external customers 157.2 99.2 179.1
Intersegment revenues 0.0 0.0 0.0
Total Operating Revenues 157.2 99.2 179.1
Cost of gas sold, incl. gross receipts taxes 93.7 37.1 108.0
Operation and maintenance expense 19.4 18.2 19.4
Depreciation and amortization expense 1.0 1.5 1.5
Interest Expense 0.0 0.0 0.0
Income tax expense (benefit) 11.1 10.8 12.8
Other segment items [1] 6.1 8.2 (10.2)
Adjusted Earnings (Loss) 25.9 23.4 47.6
Capital expenditures 0.1 0.1 0.4
Midstream [Member] | Operating Segments [Member]      
Disaggregation of Revenue [Line Items]      
Revenues from external customers 109.2 56.9 29.9
Intersegment revenues 46.3 43.8 36.2
Total Operating Revenues 155.5 100.7 66.1
Cost of gas sold, incl. gross receipts taxes 3.0 1.1 0.0
Operation and maintenance expense 45.3 34.7 30.5
Depreciation and amortization expense 19.2 12.8 8.4
Interest Expense 11.6 7.0 8.6
Income tax expense (benefit) 15.7 9.6 3.8
Other segment items [1] 4.4 2.0 0.7
Adjusted Earnings (Loss) 56.3 33.5 14.1
Capital expenditures 106.8 171.3 73.6
Other [Member]      
Disaggregation of Revenue [Line Items]      
Revenues from external customers [2] 2.5 0.7 0.7
Intersegment revenues [2] 0.0 0.0 0.0
Total Operating Revenues [2] 2.5 0.7 0.7
Cost of gas sold, incl. gross receipts taxes [2] 0.0 0.1 0.0
Operation and maintenance expense [2] 10.3 1.7 5.9
Depreciation and amortization expense [2] 0.4 0.5 0.5
Interest Expense [2] 55.4 46.8 37.2
Income tax expense (benefit) [2] (14.5) (9.7) (10.5)
Other segment items [1],[2] (11.0) (8.4) 1.7
Adjusted Earnings (Loss) [2] (38.1) (30.3) (34.1)
Capital expenditures [2] $ (1.3) $ (1.2) $ (0.1)
[1] Other segment items for each reportable segment include fair value and timing adjustments, acquisition and restructuring activities, taxes other than income and gross receipt taxes, and miscellaneous income and deductions.
[2] All other components of the Company's consolidated information include Spire's subsidiaries engaged in the operation of a propane pipeline and risk management, among other activities, and unallocated corporate items, including certain debt and associated interest costs.
v3.25.3
Segment Information - Net Economic Earnings to Net Income (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disaggregation of Revenue [Abstract]      
Net Income $ 271.7 $ 250.9 $ 217.5
Fair value and timing adjustments (10.4) (12.4) 11.4
Acquisition and restructuring activities 15.2 7.6 2.5
Income tax adjustments (1.0) 1.3 (3.3)
Adjusted Earnings $ 275.5 $ 247.4 $ 228.1
v3.25.3
Regulatory Matters - Additional Information (Details) - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Oct. 24, 2025
Oct. 23, 2025
Sep. 12, 2025
May 14, 2025
Apr. 17, 2025
Jan. 01, 2025
Dec. 04, 2024
Dec. 01, 2024
Oct. 25, 2024
Oct. 24, 2024
Jan. 01, 2024
Dec. 13, 2023
Dec. 01, 2023
Apr. 30, 2023
Jan. 01, 2023
Apr. 22, 2022
Oct. 01, 2018
Feb. 28, 2025
Sep. 30, 2022
Nov. 30, 2019
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2022
Dec. 01, 2025
Nov. 15, 2024
Public Utilities, General Disclosures [Line Items]                                                    
Utilities operating expense, gas and petroleum purchased                                         $ 905,500 $ 1,103,300 $ 1,260,800      
Spire Missouri [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities approved percentage of excess natural gas supply and capacity to customers                                         75.00%          
Public utilities approved percentage of excess natural gas supply and capacity to retain                                         25.00%          
Public utilities, value from capacity release, threshold                                         $ 2,200          
Regulatory asset, percentage change of tariff                                                   30.00%
Utilities operating expense, gas and petroleum purchased                                         669,400 886,200 943,400      
Public utilities, request rate increase (decrease), amount                                   $ 137,400                
Public utility rate base amount                                         $ 4,379,600          
Public utility after-tax total rate of return, infrastructure system replacement surcharge                                         7.05%          
Public utilities, requested rate increase (decrease), amount         $ 19,000         $ 210,000                                
Public utilities, approved rate, increase (decrease) annualized revenue       $ 72,600                                            
Spire Missouri [Member] | Infrastructure System Replacement Surcharge [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved rate increase (decrease), amount                                   $ 72,600                
Spire Alabama Inc [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Utilities operating expense, gas and petroleum purchased                                         $ 154,400 189,500 202,700      
Public utilities, rate increase decrease index range margin                                     1.50%         1.50%    
Financing Receivable, after Allowance for Credit Loss                                         5,400 5,900        
Spire Alabama Inc [Member] | Alabama Public Service Commission [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities approved percentage of excess natural gas supply and capacity to customers                                       75.00%            
Public utilities approved percentage of excess natural gas supply and capacity to retain                                       25.00%            
Public utilities, value from capacity release, threshold                               $ 1,600                    
Public utilities, approved rate increase (decrease), amount                                         $ 10,000 $ 2,500 $ 4,400      
Public utilities maximum return on equity percentage of prior year revenues                                     4.00%         4.00%    
Public utilities, approved return on equity, percentage                                 10.40%   9.70%              
Public utilities, rate increase decrease index range margin                                     0.10%         0.10%    
Public utilities, equity limitation as percent of total capitalization                                     55.50%         55.50%    
Public utilities, equity limitation as percent of average common equity growth                                     6.00%         6.00%    
Annual revenue increase from rates, amount               $ 4,000   $ 3,600 $ 14,300       $ 15,000                      
Public utilities, requested rate increase (decrease), amount                                               $ 17,200    
Spire Alabama Inc [Member] | Alabama Public Service Commission [Member] | Minimum [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved return on equity, percentage                                 10.15%   9.50%              
Spire Alabama Inc [Member] | Alabama Public Service Commission [Member] | Maximum [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved return on equity, percentage                                 10.65%   9.90%              
Spire Alabama Inc [Member] | Subsequent Event [Member] | Alabama Public Service Commission [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, equity limitation as percent of average common equity growth                                                 8.24%  
Annual revenue increase from rates, amount $ 15,600                                                  
Spire Gulf [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved return on equity, percentage                                         9.95%          
Public utilities, rate increase decrease index range margin                                     1.50%         1.50%    
Public utilities approved rate reflected benefit                                         $ 200          
Annual revenue increase from rates, amount                 $ 1,900     $ 2,700                            
Public utilities, approved rate, increase (decrease) annualized revenue             $ 1,300           $ 2,000 $ 1,800                        
Public Utilities, Approved Return on Equity, Pro-Rata, Percentage                                         75.00%          
Regulated Operating Revenue Variances Amount                                         $ 100          
Utilities Operating Expense Maintenance and Operations Self Insurance Cost Single Force Majeure Event Deferred Amount                                         100          
Utilities Operating Expense Maintenance and Operations Self Insurance Cost Multiple Force Majeure Events Deferred Amount                                         $ 150          
Regulated Operations, Recovery of Incurred Costs, Percentage                                         90.00%          
Spire Gulf [Member] | Minimum [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved return on equity, percentage                                         9.70%          
Spire Gulf [Member] | Maximum [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved return on equity, percentage                                         10.30%          
Spire Gulf [Member] | Subsequent Event [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Annual revenue increase from rates, amount   $ 3,500                                                
Spire [Member] | Maximum [Member] | Related Party [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Financing Receivable, after Allowance for Credit Loss                                         $ 25,000          
Spire [Member] | Alabama Public Service Commission [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Line of Credit Facility, Maximum Borrowing Capacity                                         $ 75,000          
Spire Mississippi [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Public utilities, approved rate increase (decrease), amount     $ 800                                              
Public utilities, approved return on equity, percentage                                         10.73%          
Public utilities, approved rate, increase (decrease) annualized revenue           $ 600         $ 1,000       $ 800                      
Public Utilities, Approved Return on Equity, Excess of Allowed Return, Percentage                                         1.00%          
Public Utilities, Approved Return on Equity Shortfall Percentage                                         75.00%          
Public Utilities, Approved Return On Equity, Excess, Percentage                                         50.00%          
Future Income Taxes Due From Customers and Pension and Other Postretirement Benefit Costs [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Remaining recovery period of regulatory assets for which no return on investment during recovery period is provided (Year)                                         20 years          
PGA Assets [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Remaining recovery period of regulatory assets for which no return on investment during recovery period is provided (Year)                                         1 year          
PGA Assets Not Earning a Return [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Remaining recovery period of regulatory assets for which no return on investment during recovery period is provided (Year)                                         15 years          
Related Debt Term and Diaphragm [Member]                                                    
Public Utilities, General Disclosures [Line Items]                                                    
Remaining recovery period of regulatory assets for which no return on investment during recovery period is provided (Year)                                         20 years          
v3.25.3
Regulatory Matters - Schedule of Regulatory Assets and Liabilities (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current $ 78.3 $ 115.4
Regulatory Assets, Noncurrent 1,323.5 1,251.8
Total Regulatory Assets 1,401.8 1,367.2
Regulatory Liabilities, Current 39.4 49.5
Regulatory Liabilities, Noncurrent 578.0 535.5
Total Regulatory Liabilities 617.4 585.0
Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 48.9 84.0
Regulatory Assets, Noncurrent 653.2 588.0
Total Regulatory Assets 702.1 672.0
Regulatory Liabilities, Current 13.9 10.2
Regulatory Liabilities, Noncurrent 481.3 443.3
Total Regulatory Liabilities 495.2 453.5
Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 16.1 19.2
Regulatory Assets, Noncurrent 650.6 642.0
Total Regulatory Assets 666.7 661.2
Regulatory Liabilities, Current 20.3 33.8
Regulatory Liabilities, Noncurrent 29.2 28.3
Total Regulatory Liabilities 49.5 62.1
Future Income Taxes Due from Customers [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 154.2 150.7
Future Income Taxes Due from Customers [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 146.6 142.7
Future Income Taxes Due from Customers [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 1.6 1.8
Deferred Taxes Due to Customers [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Liabilities, Noncurrent 100.3 114.2
Deferred Taxes Due to Customers [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Liabilities, Noncurrent 88.8 101.8
Deferred Taxes Due to Customers [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Liabilities, Noncurrent 0.0 0.0
Pension and Postretirement Benefit Costs [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 217.8 237.5
Regulatory Liabilities, Noncurrent 300.1 232.9
Pension and Postretirement Benefit Costs [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 157.0 166.5
Regulatory Liabilities, Noncurrent 261.2 196.6
Pension and Postretirement Benefit Costs [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 59.1 68.2
Regulatory Liabilities, Noncurrent 26.5 25.1
Cost of Removal [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 688.3 668.2
Regulatory Liabilities, Noncurrent 138.2 133.6
Cost of Removal [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 98.8 97.0
Regulatory Liabilities, Noncurrent 96.0 94.5
Cost of Removal [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 589.6 571.2
Regulatory Liabilities, Noncurrent 0.0 0.0
Unamortized Purchased Gas Adjustments [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 16.5 28.9
Regulatory Assets, Noncurrent 9.0 1.2
Regulatory Liabilities, Current 34.9 42.3
Regulatory Liabilities, Noncurrent 6.5 17.2
Unamortized Purchased Gas Adjustments [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 14.9 28.1
Regulatory Assets, Noncurrent 9.0 1.2
Regulatory Liabilities, Current 13.9 10.2
Regulatory Liabilities, Noncurrent 6.5 17.2
Unamortized Purchased Gas Adjustments [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 0.0 0.0
Regulatory Assets, Noncurrent 0.0 0.0
Regulatory Liabilities, Current 20.2 30.9
Regulatory Liabilities, Noncurrent 0.0 0.0
Energy Efficiency [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 65.0 61.0
Energy Efficiency [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 65.0 61.0
Energy Efficiency [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Noncurrent 0.0 0.0
Other [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 61.8 86.5
Regulatory Assets, Noncurrent 189.2 133.2
Regulatory Liabilities, Current 4.5 7.2
Regulatory Liabilities, Noncurrent 32.9 37.6
Other [Member] | Spire Missouri [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 34.0 55.9
Regulatory Assets, Noncurrent 176.8 119.6
Regulatory Liabilities, Current 0.0 0.0
Regulatory Liabilities, Noncurrent 28.8 33.2
Other [Member] | Spire Alabama Inc [Member]    
Schedule Of Regulatory Assets and Liabilities [Line Items]    
Regulatory Assets, Current 16.1 19.2
Regulatory Assets, Noncurrent 0.3 0.8
Regulatory Liabilities, Current 0.1 2.9
Regulatory Liabilities, Noncurrent $ 2.7 $ 3.2
v3.25.3
Regulatory Matters - Schedule of Regulatory Assets Not Earning Return (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Regulatory assets not earning a return $ 472.7 $ 440.4
Spire Missouri [Member]    
Regulatory assets not earning a return 466.6 434.2
Pension and Postretirement Benefit Costs [Member]    
Regulatory assets not earning a return 119.1 129.7
Pension and Postretirement Benefit Costs [Member] | Spire Missouri [Member]    
Regulatory assets not earning a return 119.1 129.7
Future Income Taxes Due from Customers [Member]    
Regulatory assets not earning a return 152.7 148.9
Future Income Taxes Due from Customers [Member] | Spire Missouri [Member]    
Regulatory assets not earning a return 146.6 142.7
Unamortized Purchased Gas Adjustments [Member]    
Regulatory assets not earning a return 23.9 29.3
Unamortized Purchased Gas Adjustments [Member] | Spire Missouri [Member]    
Regulatory assets not earning a return 23.9 29.3
Other [Member]    
Regulatory assets not earning a return 177.0 132.5
Other [Member] | Spire Missouri [Member]    
Regulatory assets not earning a return $ 177.0 $ 132.5
v3.25.3
Commitments and Contingencies - Additional Information (Details)
$ in Millions
 12 Months Ended
Sep. 30, 2025
USD ($)
Long-Term Purchase Commitment [Line Items]  
Long-term purchase commitment, amount $ 1,762.8
Capital committed to contribute to partnership 25.0
Remaining unfunded capital commitment 15.4
Spire Missouri [Member]  
Long-Term Purchase Commitment [Line Items]  
Long-term purchase commitment, amount 1,388.9
Spire Alabama Inc [Member]  
Long-Term Purchase Commitment [Line Items]  
Long-term purchase commitment, amount $ 557.2
v3.25.3
Leases - Schedule of Operating Lease Cost, Cash Flow and Noncash Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Operating lease cost, including amounts capitalized $ 7.1 $ 7.3 $ 7.3
Operating cash flows representing cash paid for amounts included in the measurement of lease liabilities 7.3 7.4 7.3
Right-of-use assets obtained in exchange for lease liabilities 0.0 0.0 0.8
Spire Missouri [Member]      
Operating lease cost, including amounts capitalized 0.5 0.5 0.5
Operating cash flows representing cash paid for amounts included in the measurement of lease liabilities 0.5 0.5 0.5
Right-of-use assets obtained in exchange for lease liabilities 0.0 0.0 0.8
Spire Alabama Inc [Member]      
Operating lease cost, including amounts capitalized 2.0 2.0 2.0
Operating cash flows representing cash paid for amounts included in the measurement of lease liabilities 2.2 2.1 2.1
Right-of-use assets obtained in exchange for lease liabilities $ 0.0 $ 0.0 $ 0.0
v3.25.3
Leases - Schedule of Balance Sheet and Weighted Average Information About Operating Leases (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Sep. 30, 2024
Right-of-use assets $ 59.2 $ 63.1
Lease liabilities, current 6.1 6.6
Lease liabilities, noncurrent $ 59.1 $ 62.7
Weighted-average remaining lease term (in years) 12 years 7 months 6 days 13 years 6 months
Weighted-average discount rate 4.20% 4.20%
Spire Missouri [Member]    
Right-of-use assets $ 1.6 $ 1.7
Lease liabilities, current 0.5 0.5
Lease liabilities, noncurrent $ 1.2 $ 1.3
Weighted-average remaining lease term (in years) 4 years 9 months 18 days 5 years 1 month 6 days
Weighted-average discount rate 3.80% 3.40%
Spire Alabama Inc [Member]    
Right-of-use assets $ 17.0 $ 18.1
Lease liabilities, current 2.0 1.9
Lease liabilities, noncurrent $ 20.9 $ 22.3
Weighted-average remaining lease term (in years) 11 years 3 months 18 days 12 years 3 months 18 days
Weighted-average discount rate 3.70% 3.70%
v3.25.3
Leases - Schedule of Balance Sheet and Weighted Average Information About Operating Leases (Details) (Parentheticals)
Sep. 30, 2025
Sep. 30, 2024
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Regulatory and Other Assets, Noncurrent Regulatory and Other Assets, Noncurrent
US Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Liabilities Current Other Liabilities Current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other libilities Other libilities
v3.25.3
Leases - Maturity of Operating Lease Liabilities (Details)
$ in Millions
Sep. 30, 2025
USD ($)
2026 $ 6.3
2027 6.7
2028 6.8
2029 6.7
2030 6.7
Thereafter 51.3
Total undiscounted lease payments 84.5
Less present value discount (19.3)
Total current and noncurrent lease liabilities 65.2
Spire Missouri [Member]  
2026 0.5
2027 0.4
2028 0.3
2029 0.3
2030 0.2
Thereafter 0.2
Total undiscounted lease payments 1.9
Less present value discount (0.2)
Total current and noncurrent lease liabilities 1.7
Spire Alabama Inc [Member]  
2026 2.0
2027 2.3
2028 2.3
2029 2.4
2030 2.4
Thereafter 16.9
Total undiscounted lease payments 28.3
Less present value discount (5.4)
Total current and noncurrent lease liabilities $ 22.9
v3.25.3
Business Combinations - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Aug. 22, 2025
Jul. 27, 2025
Sep. 30, 2025
MoGas Pipeline [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Payments to Acquire Businesses, Gross     $ 176.1
Tennessee Natural Gas [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Payments to Acquire Businesses, Gross   $ 2,480.0  
Tennessee Natural Gas [Member] | Senior Unsecured Bridge Facility [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Line of credit facility maximum borrowing capacity $ 2,480.0    
Maturity term 364 days    
Tennessee Natural Gas [Member] | Senior Unsecured Bridge Facility [Member] | Bridge Term Loan [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Line of credit facility maximum borrowing capacity $ 1,880.0    
Tennessee Natural Gas [Member] | Senior Unsecured Bridge Facility [Member] | Delayed Draw Term Loan (DDTL) [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Line of credit facility maximum borrowing capacity $ 600.0    
Tennessee Natural Gas [Member] | Secured Overnight Financing Rate (SOFR) [Member] | Senior Unsecured Bridge Facility [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Debt instrument basis spread on variable rate 1.375%    
Tennessee Natural Gas [Member] | Base Rate [Member] | Senior Unsecured Bridge Facility [Member]      
Asset Acquisition, Contingent Consideration [Line Items]      
Debt instrument basis spread on variable rate 0.375%