Right to recover for covered losses (Note 2)

^[1]

5,476

5,526

^[1]

(6)

(52)

Additional paid-in capital

16,713

16,900

Accumulated income

10,192

9,508

Accumulated other comprehensive income (loss), net:

Investment securities, available-for-sale

93

73

Defined benefit pension and other postretirement plans

(77)

(76)

Derivative instruments classified as cash flow hedges

(51)

(36)

Foreign currency translation adjustments

1,763

917

Total accumulated other comprehensive income, net

1,728

878

Total equity

34,103

32,760

Total liabilities and equity

69,042

67,977

Series A Preferred Stock

Equity

0

Equity

^[1]

2,295

2,326

Equity

Preferred stock, par value

^[1]

3,181

3,200

Equity

0

Equity

0

Equity

$ 0

[1]	Figures in the table may not recalculate exactly due to rounding. As-converted and book values are based on unrounded numbers.

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
shares in Millions

Mar. 31, 2018

Sep. 30, 2017

Preferred Stock

$ 0.0001

Preferred stock, shares authorized

25

5

5

Series A Preferred Stock

0

2

2

3

3

Common stock, shares authorized

Common stock, par value

$ 0.0001

2,001,622

Common stock, shares issued

1,790

1,818

1,790

^[1]

1,818

Common stock, shares authorized

Common stock, par value

$ 0.0001

622

Common stock, shares issued

245

245

Common stock, shares authorized

Common stock, par value

$ 0.0001

1,097

Common stock, shares issued

12

13

International transaction revenues

12

13

[1]	Class A common stock shares outstanding exclude repurchases traded but not yet settled on or before March 31, 2018.

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)
shares in Millions, $ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Operating Revenues

Service revenues

$ 2,253

$ 1,993

$ 4,399

$ 3,911

Data processing revenues

2,127

1,843

4,274

3,735

1,752

1,469

3,418

2,958

Other revenues

230

203

459

406

Client incentives

(1,289)

(1,031)

(2,615)

(2,072)

Net operating revenues

5,073

4,477

9,935

8,938

Operating Expenses

Personnel

824

704

1,503

1,275

Marketing

261

193

484

411

Network and processing

169

150

329

295

Professional fees

108

83

200

163

Depreciation and amortization

153

131

298

277

General and administrative

222

406

458

592

Litigation provision (Note 11)

0

2

0

17

Total operating expenses

1,737

1,669

3,272

3,030

Operating income

3,336

2,808

6,663

5,908

Non-operating Income (Expense)

Interest expense

(153)

(135)

(307)

(275)

Other

34

29

100

48

Total non-operating expense

(119)

(106)

(207)

(227)

Income before income taxes

3,217

2,702

6,456

5,681

Income tax provision (Note 10)

612

2,272

1,329

3,181

Net income

$ 2,605

$ 430

$ 5,127

$ 2,500

Basic earnings per share (in dollars per share)

Earnings Per Share

^[1]

$ 1.12

$ 0.18

$ 2.19

$ 1.04

Basic weighted-average shares outstanding (in shares)

1,798

1,854

1,805

1,857

Diluted earnings per share (in dollars per share)

^[1]

$ 1.11

$ 0.18

$ 2.19

$ 1.04

Diluted weighted-average shares outstanding (in shares)

^[2]

2,337

2,406

2,345

2,413

Basic earnings per share (in dollars per share)

Earnings Per Share

^[1]

$ 1.84

$ 0.30

$ 3.61

$ 1.71

Basic weighted-average shares outstanding (in shares)

245

Diluted earnings per share (in dollars per share)

^[1]

$ 1.84

$ 0.29

$ 3.60

$ 1.71

Diluted weighted-average shares outstanding (in shares)

245

Basic earnings per share (in dollars per share)

Earnings Per Share

^[1]

$ 4.46

$ 0.72

$ 8.76

$ 4.15

Basic weighted-average shares outstanding (in shares)

12

15

13

16

Diluted earnings per share (in dollars per share)

^[1]

$ 4.46

$ 0.72

$ 8.74

$ 4.14

Diluted weighted-average shares outstanding (in shares)

12

15

13

16

[1]

Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.

[2]

Weighted-average diluted shares outstanding are calculated on an as-converted basis, and include incremental common stock equivalents, as calculated under the treasury stock method. The computation includes approximately 4 million common stock equivalents for the three and six months ended March 31, 2018 and 5 million common stock equivalents for the three and six months ended March 31, 2017, because their effect would be dilutive. The computation excludes 2 million of common stock equivalents for the three and six months ended March 31, 2018 and 3 million for the three and six months ended March 31, 2017, because their effect would have been anti-dilutive.

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 2,605	$ 430	$ 5,127	$ 2,500
Investment securities, available-for-sale:
Net unrealized gain	41	19	50	16
Income tax effect	(9)	(7)	(12)	(8)
Reclassification adjustment for net (gain) loss realized in net income	0	1	(28)	1
Income tax effect	0	0	10	0
Defined benefit pension and other postretirement plans:
Net unrealized actuarial loss and prior service credit	(2)	(5)	(2)	(5)
Income tax effect	1	2	1	2
Amortization of actuarial loss and prior service credit realized in net income	0	15	0	21
Income tax effect	0	(7)	0	(9)
Derivative instruments classified as cash flow hedges:
Net unrealized (loss) gain	(41)	(49)	(42)	25
Income tax effect	2	11	(3)	4
Reclassification adjustment for net loss realized in net income	24	8	35	20
Income tax effect	(3)	(3)	(5)	(5)
Foreign currency translation adjustments	512	404	846	(584)
Other comprehensive income (loss), net of tax	525	389	850	(522)
Comprehensive income	$ 3,130	$ 819	$ 5,977	$ 1,978

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 5,127	$ 2,500
Adjustments to reconcile net income to net cash provided by operating activities:
Client incentives	2,615	2,072
Share-based compensation (Note 9)	153	116
Depreciation and amortization of property, equipment, technology and intangible assets	298	277
Deferred income taxes	(945)	1,700
Right to recover for covered losses recorded in equity (Note 2)	(4)	(163)
Charitable contribution of Visa Inc. shares (Note 10)	0	192
Other	(13)	23
Change in operating assets and liabilities:
Settlement receivable	(1,039)	(1,946)
Accounts receivable	(113)	(40)
Client incentives	(2,177)	(2,306)
Other assets	(103)	(301)
Accounts payable	(26)	(83)
Settlement payable	986	883
Accrued and other liabilities	975	(35)
Accrued litigation (Note 11)	(152)	15
Net cash provided by operating activities	5,582	2,904
Investing Activities
Purchases of property, equipment, technology and intangible assets	(354)	(317)
Investment securities, available-for-sale:
Purchases	(2,342)	(1,083)
Proceeds from maturities and sales	1,771	3,972
Acquisition of business, net of cash received	196	302
Purchases of / contributions to other investments	(16)	(2)
Net cash (used in) provided by investing activities	(1,137)	2,268
Financing Activities
Repayments of long-term debt (Note 4)	(1,750)	0
Dividends paid (Note 7)	(948)	(795)
Payments from litigation escrow account—U.S. retrospective responsibility plan (Note 2 and Note 11)	150	0
Cash proceeds from issuance of common stock under employee equity plans	103	87
Restricted stock and performance-based shares settled in cash for taxes	(88)	(66)
Net cash used in financing activities	(6,383)	(4,243)
Effect of exchange rate changes on cash and cash equivalents	206	(121)
(Decrease) increase in cash and cash equivalents	(1,732)	808
Cash and cash equivalents at beginning of period	9,874	5,619
Cash and cash equivalents at end of period	8,142	6,427
Supplemental Disclosure
Income taxes paid, net of refunds	1,197	1,611
Interest payments on debt (Note 4)	276	244
Accruals related to purchases of property, equipment, technology and intangible assets	21	37
Class A common stock
Financing Activities
Repurchase of class A common stock (Note 7)	$ (3,850)	$ (3,469)

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1—Summary of Significant Accounting Policies Organization. Visa Inc. ("Visa" or the "Company") is a global payments technology company that enables fast, secure and reliable electronic payments across more than 200 countries and territories. Visa and its wholly-owned consolidated subsidiaries, including Visa U.S.A. Inc. ("Visa U.S.A."), Visa International Service Association ("Visa International"), Visa Worldwide Pte. Limited, Visa Europe Limited ("Visa Europe"), Visa Canada Corporation, Visa Technology & Operations LLC and CyberSource Corporation, operate one of the world’s largest retail electronic payments networks — VisaNet — which facilitates authorization, clearing and settlement of payment transactions and enables the Company to provide its financial institution and merchant clients a wide range of products, platforms and value-added services. VisaNet also offers fraud protection for account holders and assured payment for merchants. Visa is not a bank and does not issue cards, extend credit or set rates and fees for account holders on Visa products. In most cases, account holder and merchant relationships belong to, and are managed by, Visa's financial institution clients. Consolidation and basis of presentation. The accompanying unaudited consolidated financial statements include the accounts of Visa and its consolidated entities and are presented in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"). The Company consolidates its majority-owned and controlled entities, including variable interest entities ("VIEs") for which the Company is the primary beneficiary. The Company’s investments in VIEs have not been material to its consolidated financial statements as of and for the periods presented. All significant intercompany accounts and transactions are eliminated in consolidation. The accompanying unaudited consolidated financial statements are presented in accordance with the U.S. Securities and Exchange Commission (SEC) requirements for Quarterly Reports on Form 10-Q and, consequently, do not include all of the annual disclosures required by U.S. GAAP. Reference should be made to the Visa Annual Report on Form 10-K for the year ended September 30, 2017 for additional disclosures, including a summary of the Company’s significant accounting policies. In the opinion of management, the accompanying unaudited consolidated financial statements include all normal recurring adjustments necessary for a fair presentation of the Company's financial position, results of operations and cash flows for the interim periods presented. Recently Issued and Adopted Accounting Pronouncements. In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of goods or services to customers. The ASU replaces existing revenue recognition guidance in U.S. GAAP. Subsequently, the FASB also issued a series of amendments to the new revenue standard. The Company will adopt the standard effective October 1, 2018, and expects to adopt the standard using the modified retrospective transition method. The Company expects that the new standard will primarily impact recognition timing for certain fixed incentives and price discounts provided to clients, and the classification of certain client incentives between contra revenues and operating expenses. The impact of the new standard to future financial results is unknowable as it is not possible to estimate the impact to the recognition of new customer contracts which may be executed in future periods. The Company has completed an assessment of its existing customer contracts through March 31, 2018. Application of the new standard to consolidated financial statements for the first two quarters of fiscal 2018 would not have resulted in a material impact. The Company will continue to assess the impact of the new standard as new customer contracts are executed going forward. In March 2016, the FASB issued ASU 2016-05, which clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815, Derivatives and Hedging, does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted the standard effective October 1, 2017. The adoption did not have a material impact on the consolidated financial statements. In March 2016, the FASB issued ASU 2016-06, which clarifies the requirements for assessing whether contingent call/put options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. An entity performing the assessment is required to assess the embedded call/put options solely in accordance with a four-step decision sequence. The Company adopted the standard effective October 1, 2017. The adoption did not have a material impact on the consolidated financial statements. In March 2016, the FASB issued ASU 2016-07, which eliminates the requirement that an entity retroactively adopt the equity method of accounting if an investment qualifies for use of the equity method as a result of an increase in the level of ownership or degree of influence. The equity method investor is required to add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted the standard effective October 1, 2017. The adoption did not have a material impact on the consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, which allows a reclassification from accumulated other comprehensive income to retained earnings for adjustments to tax effects that were originally recorded in other comprehensive income due to changes in the U.S. federal corporate income tax rate resulting from the enactment of the U.S. tax reform legislation, commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Company will adopt the standard effective October 1, 2019. The adoption is not expected to have a material impact on the consolidated financial statements. In March 2018, the FASB issued ASU 2018-05 to insert the SEC's interpretive guidance from Staff Accounting Bulletin No. 118 into the income tax accounting codification under U.S. GAAP. The ASU permits companies to use provisional amounts for certain income tax effects of the Tax Act during a one-year measurement period. The provisional accounting impacts for the Company may change in future reporting periods until the accounting analysis is finalized, which will occur no later than the first quarter of fiscal 2019.

U.S. and Europe Retrospective Responsibility Plans

6 Months Ended

Mar. 31, 2018

Retrospective Responsibility Plan [Abstract]

U.S. and Europe Retrospective Responsibility Plans

Note 2—U.S. and Europe Retrospective Responsibility Plans

U.S. Retrospective Responsibility Plan

Under the terms of the U.S. retrospective responsibility plan, the Company maintains an escrow account from which settlements of, or judgments in, certain litigation referred to as the "U.S. covered litigation" are paid. The escrow funds are held in money market investments along with interest income earned, less applicable taxes and are classified as restricted cash on the consolidated balance sheets. The balance of the escrow account was $0.9 billion at March 31, 2018 and $1.0 billion at September 30, 2017. The Company paid $150 million from the litigation escrow account during the six months ended March 31, 2018. See Note 11—Legal Matters.

The accrual related to the U.S. covered litigation could be either higher or lower than the litigation escrow account balance. The Company did not record an additional accrual for the U.S. covered litigation during the six months ended March 31, 2018. See Note 11—Legal Matters.

Europe Retrospective Responsibility Plan

Visa Inc., Visa International and Visa Europe are parties to certain existing and potential litigation relating to the setting of multilateral interchange fee rates in the Visa Europe territory (the "VE territory covered litigation"). Under the terms of the Europe retrospective responsibility plan, the Company is entitled to recover certain losses resulting from VE territory covered litigation (the "VE territory covered losses") through a periodic adjustment to the class A common stock conversion rates applicable to the UK&I and Europe preferred stock. VE territory covered losses are recorded in "right to recover for covered losses" within equity before the corresponding adjustment to the applicable conversion rate is effected. Adjustments to the conversion rate may be executed once in any six-month period unless a single, individual loss greater than €20 million is incurred, in which case, the six-month limitation does not apply. When the adjustment to the conversion rate is made, the amount previously recorded in "right to recover for covered losses" as contra-equity is then recorded against the book value of the preferred stock within stockholders' equity.

During the six months ended March 31, 2018, the Company recovered $50 million of VE territory covered losses through adjustments to the class A common stock conversion rates applicable to the UK&I and Europe preferred stock, from 13.077 and 13.948, respectively, at September 30, 2017 to 12.966 and 13.893, respectively, at March 31, 2018.

The following table sets forth the activities related to VE territory covered losses in preferred stock and "right to recover for covered losses" within equity during the six months ended March 31, 2018. VE territory covered losses incurred reflect settlements with merchants and additional legal costs. See Note 11—Legal Matters.



	Preferred Stock						Right to Recover for Covered Losses
	UK&I			Europe			Right to Recover for Covered Losses
	(in millions)
Balance as of September 30, 2017	$	2,326		$	3,200		$	(52	)
VE territory covered losses incurred	—			—			(4		)
Recovery through conversion rate adjustment	(31		)	(19		)	50
Balance as of March 31, 2018	$	2,295		$	3,181		$	(6	)

The following table sets forth the as-converted value of the preferred stock available to recover VE territory covered losses compared to the book value of preferred shares recorded in stockholders' equity within the Company's unaudited consolidated balance sheet as of March 31, 2018 and September 30, 2017.⁽¹⁾



	March 31, 2018						September 30, 2017
	As-Converted Value of Preferred Stock⁽²⁾			Book Value of Preferred Stock			As-Converted Value of Preferred Stock⁽³⁾			Book Value of Preferred Stock
	(in millions)
UK&I preferred stock	$	3,847		$	2,295		$	3,414		$	2,326
Europe preferred stock	5,246			3,181			4,634			3,200
Total	9,093			5,476			8,048			5,526
Less: right to recover for covered losses	(6		)	(6		)	(52		)	(52		)
Total recovery for covered losses available	$	9,087		$	5,470		$	7,996		$	5,474


⁽¹⁾	Figures in the table may not recalculate exactly due to rounding. As-converted and book values are based on unrounded numbers.

⁽²⁾

The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of March 31, 2018; (b)12.966 and 13.893, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of March 31, 2018, respectively; and (c) $119.62, Visa's class A common stock closing stock price as of March 31, 2018.

⁽³⁾

The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of September 30, 2017; (b)13.077 and 13.948, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of September 30, 2017, respectively; and (c) $105.24, Visa's class A common stock closing stock price as of September 30, 2017.

Fair Value Measurements and Investments

6 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements and Investments

Note 3—Fair Value Measurements and Investments

Fair Value Measurements

Assets and Liabilities Measured at Fair Value on a Recurring Basis



	Fair Value Measurements Using Inputs Considered as
	Level 1				Level 2
	March 31, 2018		September 30, 2017		March 31, 2018		September 30, 2017
	(in millions)
Assets
Cash equivalents and restricted cash:
Money market funds	$	6,141	$	5,935
U.S. government-sponsored debt securities					$	272	$	2,870
Investment securities, trading:
Equity securities	94		82
Investment securities, available-for-sale:
U.S. government-sponsored debt securities					3,641		3,663
U.S. Treasury securities	2,284		1,621
Equity securities	160		124
Prepaid and other current assets:
Foreign exchange derivative instruments					12		18
Total	$	8,679	$	7,762	$	3,925	$	6,551
Liabilities
Accrued liabilities:
Foreign exchange derivative instruments					$	82	$	98
Total	$	—	$	—	$	82	$	98

There were no transfers between Level 1 and Level 2 assets during the six months ended March 31, 2018.

Level 1 assets measured at fair value on a recurring basis. Money market funds, publicly-traded equity securities and U.S. Treasury securities are classified as Level 1 within the fair value hierarchy, as fair value is based on quoted prices in active markets.

Level 2 assets and liabilities measured at fair value on a recurring basis. The fair value of U.S. government-sponsored debt securities, as provided by third-party pricing vendors, is based on quoted prices in active markets for similar, not identical, assets. The pricing data obtained from outside sources is reviewed internally for reasonableness, compared against benchmark quotes from independent pricing sources, then confirmed or revised accordingly. Foreign exchange derivative instruments are valued using inputs that are observable in the market or can be derived principally from or corroborated by observable market data. There were no substantive changes to the valuation techniques and related inputs used to measure fair value during the six months ended March 31, 2018.

Assets Measured at Fair Value on a Non-recurring Basis

Non-marketable equity investments and investments accounted for under the equity method. These investments are classified as Level 3 due to the absence of quoted market prices, the inherent lack of liquidity, and the fact that inputs used to measure fair value are unobservable and require management's judgment. When certain events or circumstances indicate that impairment may exist, the Company revalues the investments using various assumptions, including the financial metrics and ratios of comparable public companies. There were no significant impairments during the six months ended March 31, 2018 or 2017. These investments totaled $109 million and $94 million at March 31, 2018 and September 30, 2017, respectively, and are classified in other assets on the consolidated balance sheets.

Non-financial assets and liabilities. Long-lived assets such as goodwill, indefinite-lived intangible assets, finite-lived intangible assets, and property, equipment and technology are considered non-financial assets. The Company does not have any non-financial liabilities measured at fair value on a non-recurring basis. Finite-lived intangible assets primarily consist of customer relationships, trade names and reseller relationships, all of which were obtained through acquisitions.

If the Company were required to perform a quantitative assessment for impairment testing of goodwill and indefinite-lived intangible assets, the fair values would generally be estimated using an income approach. As the assumptions employed to measure these assets on a non-recurring basis are based on management's judgment using internal and external data, these fair value determinations are classified as Level 3 in the fair value hierarchy. The Company completed its annual impairment review of its indefinite-lived intangible assets and goodwill as of February 1, 2018, and concluded that there was no impairment. No recent events or changes in circumstances indicate that impairment existed at March 31, 2018.

Other Fair Value Disclosures

Long-term debt. Debt instruments are measured at amortized cost on the Company's unaudited consolidated balance sheet at March 31, 2018. The fair value of the debt instruments, as provided by third-party pricing vendors, is based on quoted prices in active markets for similar, not identical, assets. The pricing data obtained from outside sources is reviewed internally for reasonableness, compared against benchmark quotes from independent pricing sources, then confirmed or revised accordingly. If measured at fair value in the financial statements, these instruments would be classified as Level 2 in the fair value hierarchy.

The following table presents the carrying amount and estimated fair value of the Company’s debt in order of maturity:



	March 31, 2018				September 30, 2017
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
	(in millions)
1.20% Senior Notes due December 2017	$	—	$	—	$	1,749	$	1,751
2.20% Senior Notes due December 2020	2,992		2,953		2,990		3,031
2.15% Senior Notes due September 2022	994		964		993		997
2.80% Senior Notes due December 2022	2,241		2,221		2,240		2,301
3.15% Senior Notes due December 2025	3,969		3,923		3,967		4,098
2.75% Senior Notes due September 2027	740		707		740		737
4.15% Senior Notes due December 2035	1,486		1,597		1,485		1,637
4.30% Senior Notes due December 2045	3,462		3,754		3,463		3,873
3.65% Senior Notes due September 2047	740		729		740		746
Total	$	16,624	$	16,848	$	18,367	$	19,171

Other financial instruments not measured at fair value. The following financial instruments are not measured at fair value on the Company's unaudited consolidated balance sheet at March 31, 2018, but disclosure of their fair values is required: time deposits recorded in prepaid expenses and other current assets, settlement receivable and payable, and customer collateral. The estimated fair value of such instruments at March 31, 2018 approximates their carrying value due to their generally short maturities. If measured at fair value in the financial statements, these financial instruments would be classified as Level 2 in the fair value hierarchy.

Investments

Available-for-sale investment securities. The Company had $156 million in gross unrealized gains and $18 million in gross unrealized losses at March 31, 2018. There were $120 million gross unrealized gains and $4 million gross unrealized losses at September 30, 2017. A majority of the Company's long-term available-for-sale investment securities have stated maturities between one to two years.

Settlement Guarantee Management [Abstract]

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Debt

6 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Debt

Note 4—Debt

The Company had outstanding debt as follows:



	March 31, 2018							September 30, 2017
	Principal Amount		Unamortized Discounts and Debt Issuance Costs			Carrying Amount		Principal Amount		Unamortized Discounts and Debt Issuance Costs			Carrying Amount		Effective Interest Rate
	(in millions, except percentages)
1.20% Senior Notes due December 2017 (the "2017 Notes")	$	—	$	—		$	—	$	1,750	$	(1	)	$	1,749	1.37	%
Total current maturities of long-term debt	—		—			—		1,750		(1		)	1,749

2.20% Senior Notes due December 2020	3,000		(8		)	2,992		3,000		(10		)	2,990		2.30	%
2.15% Senior Notes due September 2022	1,000		(6		)	994		1,000		(7		)	993		2.30	%
2.80% Senior Notes due December 2022	2,250		(9		)	2,241		2,250		(10		)	2,240		2.89	%
3.15% Senior Notes due December 2025	4,000		(31		)	3,969		4,000		(33		)	3,967		3.26	%
2.75% Senior Notes due September 2027	750		(10		)	740		750		(10		)	740		2.91	%
4.15% Senior Notes due December 2035	1,500		(14		)	1,486		1,500		(15		)	1,485		4.23	%
4.30% Senior Notes due December 2045	3,500		(38		)	3,462		3,500		(37		)	3,463		4.37	%
3.65% Senior Notes due September 2047	750		(10		)	740		750		(10		)	740		3.73	%
Total long-term debt	16,750		(126		)	16,624		16,750		(132		)	16,618

Total debt	$	16,750	$	(126	)	$	16,624	$	18,500	$	(133	)	$	18,367

Senior Notes

On October 11, 2017, the Company redeemed all of the $1.75 billion principal amount outstanding of the 2017 Notes. The redemption was funded with net proceeds from new fixed-rate senior notes issued by the Company in September 2017. As a result of this redemption, the Company recorded a $1 million loss on extinguishment of debt during the six months ended March 31, 2018.

The Company recognized interest expense, as non-operating expense, for the senior notes of $137 million and $275 million for the three and six months ended March 31, 2018, respectively, as compared to $125 million and $250 million for the same periods in 2017.

Settlement Guarantee Management

6 Months Ended

Mar. 31, 2018

Settlement Guarantee Management

Note 5—Settlement Guarantee Management

The Company indemnifies its clients for settlement losses suffered due to failure of any other clients to fund its settlement obligations in accordance with the Visa rules. This indemnification creates settlement risk for the Company due to the difference in timing between the date of a payment transaction and the date of subsequent settlement. The Company’s settlement exposure is limited to the amount of unsettled Visa payment transactions at any point in time. The Company requires certain clients that do not meet its credit standards to post collateral to offset potential losses from their estimated unsettled transactions. The Company’s estimated maximum settlement exposure was $72.7 billion during the three months ended March 31, 2018, compared to $67.7 billion during the three months ended September 30, 2017. Of these amounts, $2.7 billion and $2.8 billion were covered by collateral at March 31, 2018 and September 30, 2017, respectively. The total available collateral balances presented in the table below were greater than the settlement exposure covered by customer collateral held due to instances in which the available collateral exceeded the total settlement exposure for certain financial institutions at each date presented.

The Company maintained collateral as follows:



	March 31, 2018		September 30, 2017
	(in millions)
Cash equivalents⁽¹⁾	$	1,684	$	1,490
Pledged securities at market value	166		167
Letters of credit	1,351		1,316
Guarantees	653		941
Total	$	3,854	$	3,914


⁽¹⁾	Cash collateral held by Visa Europe is not included on the Company's consolidated balance sheets as its clients retain beneficial ownership and the cash is only accessible to the Company in the event of default by the client on its settlement obligations.

Historically, the Company has experienced minimal losses as a result of its settlement risk guarantee. However, the Company’s future obligations, which could be material under its guarantees, are not determinable as they are dependent upon future events.

Pension and Other Postretirement Benefits

6 Months Ended

Mar. 31, 2018

Retirement Benefits [Abstract]

Pension and Other Postretirement Benefits



	Pension Benefits
	U.S. Plans						Non-U.S. Plans
	Three Months Ended March 31,						Three Months Ended March 31,
	2018			2017			2018			2017
	(in millions)
Service cost	$	—		$	—		$	1		$	1
Interest cost	8			9			3			2
Expected return on plan assets	(18		)	(17		)	(5		)	(4		)
Amortization of actuarial loss	—			4			—			1
Settlement loss	—			11			—			—
Total net periodic benefit cost	$	(10	)	$	7		$	(1	)	$	—



	Pension Benefits
	U.S. Plans						Non-U.S. Plans
	Six Months Ended March 31,						Six Months Ended March 31,
	2018			2017			2018			2017
	(in millions)
Service cost	$	—		$	—		$	2		$	3
Interest cost	16			18			6			5
Expected return on plan assets	(35		)	(35		)	(10		)	(8		)
Amortization of actuarial loss	—			8			—			1
Settlement loss	—			13			—			—
Total net periodic benefit cost	$	(19	)	$	4		$	(2	)	$	1

Stockholders' Equity

6 Months Ended

Mar. 31, 2018

Stockholders' Equity Note [Abstract]

Stockholders' Equity

Note 7—Stockholders' Equity

As-Converted Class A Common Stock. The number of shares of each series and class and the number of shares of class A common stock on an as-converted basis at March 31, 2018, are as follows:



(in millions, except conversion rates)	Shares Outstanding	Conversion Rate Into Class A Common Stock		As-converted Class A Common Stock⁽¹⁾
UK&I preferred stock	2	12.9660		32
Europe preferred stock	3	13.8930		44
Class A common stock⁽²⁾	1,790	—		1,790
Class B common stock	245	1.6483	⁽³⁾	405
Class C common stock	12	4.0000		49
Total				2,320


⁽¹⁾	Figures in the table may not recalculate exactly due to rounding. As-converted class A common stock is calculated based on unrounded numbers.


⁽²⁾	Class A common stock shares outstanding exclude repurchases traded but not yet settled on or before March 31, 2018.


⁽³⁾	The class B to class A common stock conversion rate is presented on a rounded basis. Conversion calculations for dividend payments are based on a conversion rate rounded to the tenth decimal.

Reduction in as-converted shares. During the six months ended March 31, 2018, total as-converted class A common stock was reduced by 34 million shares at an average price of $115.36 per share. Of the 34 million shares, 33 million were repurchased in the open market using $3.9 billion of operating cash on hand. Additionally, the Company recovered $50 million of VE territory covered losses in accordance with the Europe retrospective responsibility plan during the six months ended March 31, 2018. The recovery has the same economic effect on earnings per share as repurchasing the Company's class A common stock, because it reduces the UK&I and Europe preferred stock conversion rates and consequently the as-converted class A common stock share count. See Note 2—U.S. and Europe Retrospective Responsibility Plans.

The following table presents share repurchases in the open market.⁽¹⁾



(in millions, except per share data)	Three Months Ended March 31, 2018		Six Months Ended March 31, 2018
Shares repurchased in the open market⁽²⁾	17		33
Average repurchase price per share⁽³⁾	$	120.26	$	115.41
Total cost	$	2,072	$	3,850


⁽¹⁾	Shares repurchased in the open market reflect repurchases settled during the three and six months ended March 31, 2018. These amounts include repurchases traded but not yet settled on or before September 30, 2017 for the six months, or December 31, 2017 for the three months, and exclude repurchases traded but not yet settled on or before March 31, 2018.


⁽²⁾	All shares repurchased in the open market have been retired and constitute authorized but unissued shares.


⁽³⁾	Figures in the table may not recalculate exactly due to rounding. Average repurchase price per share is calculated based on unrounded numbers.

In January 2018, the Company's board of directors authorized an additional $7.5 billion share repurchase program. As of March 31, 2018, the Company's April 2017 and January 2018 share repurchase programs had combined remaining authorized funds of $7.5 billion for share repurchase. All share repurchase programs authorized prior to April 2017 have been completed.

Under the terms of the Europe retrospective responsibility plan, the Company is entitled to recover VE territory covered losses through periodic adjustments to the class A common stock conversion rates applicable to the UK&I and Europe preferred stock. See Note 2—U.S. and Europe Retrospective Responsibility Plans.

The following table presents as-converted UK&I and Europe preferred stock, after the Company recovered VE territory covered losses through conversion rate adjustments, for the six months ended March 31, 2018. The Company did not have any adjustment recorded for UK&I and Europe preferred stock during the three months ended March 31, 2018.



	Six Months Ended March 31, 2018
(in millions, except per share data)	UK&I Preferred Stock		Europe Preferred Stock
Reduction in equivalent number of shares of class A common stock⁽¹⁾	—		—
Effective price per share⁽²⁾	$	111.32	$	111.32
Recovery through conversion rate adjustment	$	31	$	19


⁽¹⁾	The reduction in equivalent number of shares of class A common stock was less than one million shares for both series of preferred stock.


⁽²⁾	Effective price per share is calculated using the volume-weighted average price of the Company's class A common stock over a pricing period in accordance with the Company's current certificates of designations for its series B and C convertible participating preferred stock.

Dividends. In April 2018, the Company’s board of directors declared a quarterly cash dividend of $0.21 per share of class A common stock (determined in the case of class B and C common stock and UK&I and Europe preferred stock on an as-converted basis). The cash dividend will be paid on June 5, 2018, to all holders of record as of May 18, 2018. The Company declared and paid $490 million and $948 million in dividends to holders of the Company's common stock during the three and six months ended March 31, 2018, respectively.

Earnings Per Share

6 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Earnings Per Share

Note 8—Earnings Per Share

Basic earnings per share is computed by dividing net income available to each class by the weighted-average number of shares of common stock outstanding and participating securities during the period. Net income is allocated to each class of common stock and participating securities based on its proportional ownership on an as-converted basis. The weighted-average number of shares of each class of common stock outstanding reflects changes in ownership over the periods presented. See Note 7—Stockholders' Equity.

Diluted earnings per share is computed by dividing net income available by the weighted-average number of shares of common stock outstanding, participating securities and, if dilutive, potential class A common stock equivalent shares outstanding during the period. Dilutive class A common stock equivalents may consist of: (1) shares of class A common stock issuable upon the conversion of UK&I and Europe preferred stock and class B and C common stock based on the conversion rates in effect through the period, and (2) incremental shares of class A common stock calculated by applying the treasury stock method to the assumed exercise of employee stock options, the assumed purchase of stock under the Employee Stock Purchase Plan and the assumed vesting of unearned performance shares.

The following table presents earnings per share for the three months ended March 31, 2018.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	2,007	1,798	$	1.12	$	2,605	2,337	⁽³⁾	$	1.11
Class B common stock	452		245	$	1.84	$	451	245		$	1.84
Class C common stock	55		12	$	4.46	$	55	12		$	4.46
Participating securities⁽⁴⁾	91		Not presented	Not presented		$	91	Not presented		Not presented
Net income	$	2,605

The following table presents earnings per share for the six months ended March 31, 2018.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	3,952	1,805	$	2.19	$	5,127	2,345	⁽³⁾	$	2.19
Class B common stock	886		245	$	3.61	$	885	245		$	3.60
Class C common stock	110		13	$	8.76	$	109	13		$	8.74
Participating securities⁽⁴⁾	179		Not presented	Not presented		$	178	Not presented		Not presented
Net income	$	5,127

The following table presents earnings per share for the three months ended March 31, 2017.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	332	1,854	$	0.18	$	430	2,406	⁽³⁾	$	0.18
Class B common stock	73		245	$	0.30	$	72	245		$	0.29
Class C common stock	10		15	$	0.72	$	10	15		$	0.72
Participating securities⁽⁴⁾	15		Not presented	Not presented		$	15	Not presented		Not presented
Net income	$	430

The following table presents earnings per share for the six months ended March 31, 2017.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	1,928	1,857	$	1.04	$	2,500	2,413	⁽³⁾	$	1.04
Class B common stock	420		245	$	1.71	$	419	245		$	1.71
Class C common stock	65		16	$	4.15	$	65	16		$	4.14
Participating securities⁽⁴⁾	87		Not presented	Not presented		$	87	Not presented		Not presented
Net income	$	2,500


⁽¹⁾	Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.

⁽²⁾

Net income is allocated based on proportional ownership on an as-converted basis. The weighted-average number of shares of as-converted class B common stock used in the income allocation was 405 million for the three and six months ended March 31, 2018 and 2017. The weighted-average number of shares of as-converted class C common stock used in the income allocation was 49 million and 50 million for the three and six months ended March 31, 2018, respectively, and 58 million and 63 million for the three and six months ended March 31, 2017, respectively. The weighted-average number of shares of preferred stock, included within participating securities, was 32 million of as-converted UK&I preferred stock for the three and six months ended March 31, 2018, 34 million of as-converted UK&I preferred stock for three and six months ended March 31, 2017 and 44 million of as-converted Europe preferred stock for the three and six months ended March 31, 2018 and 2017.

⁽³⁾

Weighted-average diluted shares outstanding are calculated on an as-converted basis, and include incremental common stock equivalents, as calculated under the treasury stock method. The computation includes approximately 4 million common stock equivalents for the three and six months ended March 31, 2018 and 5 million common stock equivalents for the three and six months ended March 31, 2017, because their effect would be dilutive. The computation excludes 2 million of common stock equivalents for the three and six months ended March 31, 2018 and 3 million for the three and six months ended March 31, 2017, because their effect would have been anti-dilutive.

⁽⁴⁾

Participating securities include preferred stock outstanding and unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents, such as the Company's UK&I and Europe preferred stock, restricted stock awards, restricted stock units and earned performance-based shares. Participating securities' income is allocated based on the weighted-average number of shares of as-converted stock.

Share-based Compensation

6 Months Ended

Mar. 31, 2018

Share-based Compensation [Abstract]

Share-based Compensation

Note 9—Share-based Compensation

The Company granted the following equity awards to employees and non-employee directors under the 2007 Equity Incentive Compensation Plan during the six months ended March 31, 2018:



	Granted	Weighted-Average Grant Date Fair Value		Weighted-Average Exercise Price
Non-qualified stock options	1,622,760	$	17.88	$	109.82
Restricted stock units ("RSUs")	2,714,648	$	110.19
Performance-based shares⁽¹⁾	641,498	$	120.11


⁽¹⁾	Represents the maximum number of performance-based shares which could be earned.

The Company’s non-qualified stock options and RSUs are equity awards with service-only conditions and are accordingly expensed on a straight-line basis over the vesting period. The Company's performance-based shares are equity awards with service, market and performance conditions that are accounted for using the graded-vesting method. The Company recorded share-based compensation cost of $153 million for the six months ended March 31, 2018, net of estimated forfeitures, which are adjusted as appropriate.

Income Taxes

6 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

Note 10—Income Taxes

The effective income tax rates were 19% and 21% for the three and six months ended March 31, 2018, respectively, and 84% and 56% for the three and six months ended March 31, 2017, respectively. The effective tax rates for the three and six months ended March 31, 2018 differ from the effective tax rates in the same prior-year periods primarily due to:


•	the effects of the Tax Act, enacted during the quarter ended December 31, 2017, as discussed below;


•	an $80 million benefit due to a non-recurring audit settlement during the quarter ended March 31, 2018; and


•	the absence of the following items related to the Visa Europe reorganization recorded during the quarter ended March 31, 2017:


▪	a $1.5 billion non-recurring, non-cash income tax provision primarily related to the elimination of deferred tax balances originally recognized upon the acquisition of Visa Europe; and


▪	a $71 million one-time tax benefit related to the Visa Foundation's receipt of Visa Inc. shares, previously recorded by Visa Europe as treasury stock.

The Tax Act, enacted on December 22, 2017, transitions the U.S. tax system to a new territorial system and lowers the statutory federal corporate income tax rate from 35% to 21%. The reduction of the statutory federal corporate tax rate to 21% became effective on January 1, 2018. In fiscal 2018, the Company’s statutory federal corporate rate is a blended rate of 24.5%, which will be reduced to 21% in fiscal 2019 and thereafter.

As a result of the reduction in the federal corporate tax rate, the Company remeasured its net deferred tax liabilities as of the enactment date of the Tax Act. The deferred tax remeasurement resulted in a one-time, non-cash tax benefit estimated to be approximately $1.1 billion, recorded in the three months ended December 31, 2017.

In transitioning to the new territorial tax system, the Tax Act requires the Company to include certain untaxed foreign earnings of non-U.S. subsidiaries in its fiscal 2018 taxable income. Such foreign earnings are subject to a one-time tax at 15.5% on the amount held in cash or cash equivalents, and at 8% on the remaining non-cash amount. The 15.5% and 8% tax, collectively referred to as the “transition tax”, was estimated to be $1.1 billion, and was recorded in the three months ended December 31, 2017. The Company intends to elect to pay the transition tax over a period of eight years as permitted by the Tax Act.

The above-mentioned accounting impacts of the deferred tax remeasurement and transition tax are provisional, based on currently available information and technical guidance on the interpretations of the new law. The Company continues to obtain and analyze additional information and guidance as they become available to complete the accounting for the tax impacts of the Tax Act. Additional information currently unavailable that is needed to complete the analysis includes, but is not limited to, foreign tax returns and foreign tax documentation for the computation of foreign tax credits, the final determination of the untaxed foreign earnings subject to the transition tax, and the final determination of the net deferred tax liabilities subject to remeasurement. The provisional accounting impacts may change in future reporting periods until the accounting analysis is finalized, which will occur no later than the first quarter of fiscal 2019, as permitted by ASU 2018-05.

The Tax Act also introduces several tax provisions, including:

•

Tax on global intangible low-tax income, which, in general, is determined annually based on the Company’s aggregate foreign subsidiaries’ income in excess of certain qualified business asset investment return. This provision is effective for the Company on October 1, 2018. The Company needs additional information to complete its analysis on whether to adopt an accounting policy to account for the tax effects of global intangible low-tax income in the period that it is subject to such tax, or to provide deferred taxes for book and tax basis differences that, upon reversal, may be subject to such tax. Hence, the Company has not recorded any tax on global intangible low-tax income in the six months ended March 31, 2018. The Company will make an accounting policy election no later than the first quarter of fiscal 2019.


•	Base erosion and anti-abuse tax, which, in general, functions like a minimum tax that partially disallows deductions for certain related party transactions. This new minimum tax is determined on a year-by-year basis, and this provision is effective for the Company on October 1, 2018. Hence, no base erosion anti-abuse tax has been recorded in the six months ended March 31, 2018.


•	Deduction for foreign-derived intangible income, which, in general, allows a deduction of certain intangible income derived from serving foreign markets. This provision is effective for the Company on October 1, 2018. Hence, the Company has not recorded the impact of this provision in the six months ended March 31, 2018.

•

Other new tax provisions, which disallow certain deductions related to entertainment expenses, fringe benefits provided to employees, executive compensation, and fines or penalties or similar payments to governments. The Company has recorded provisional amounts for the tax effects of these new provisions in the six months ended March 31, 2018, based on information currently available. The provisional amounts may change in future reporting periods when additional information is obtained and analyzed, which will occur no later than the first quarter of fiscal 2019.

During the three and six months ended March 31, 2018, the Company's gross unrecognized tax benefits decreased by $51 million and $7 million, respectively. The Company's net unrecognized tax benefits that, if recognized, would favorably impact the effective tax rate decreased by $34 million during the three months ended March 31, 2018 and increased by $4 million during the six months ended March 31, 2018. The change in unrecognized tax benefits is primarily related to an audit settlement as well as various tax positions across several jurisdictions. During the three and six months ended March 31, 2018 and 2017, there were no significant changes in interest and penalties related to uncertain tax positions.

The Company’s tax filings are subject to examination by the U.S. federal, state and foreign taxing authorities. The timing and outcome of the final resolutions of the various ongoing income tax examinations are highly uncertain. It is not reasonably possible to estimate the increase or decrease in unrecognized tax benefits within the next twelve months.

Legal Matters

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Legal Matters [Abstract]

Legal Matters

Note 11—Legal Matters

The Company is party to various legal and regulatory proceedings. Some of these proceedings involve complex claims that are subject to substantial uncertainties and unascertainable damages. Accordingly, except as disclosed, the Company has not established reserves or ranges of possible loss related to these proceedings, as at this time in the proceedings, the matters do not relate to a probable loss and/or the amount or range of losses are not reasonably estimable. Although the Company believes that it has strong defenses for the litigation and regulatory proceedings described below, it could, in the future, incur judgments or fines or enter into settlements of claims that could have a material adverse effect on the Company's financial position, results of operations or cash flows. From time to time, the Company may engage in settlement discussions or mediations with respect to one or more of its outstanding litigation matters, either on its own behalf or collectively with other parties.

The litigation accrual is an estimate and is based on management’s understanding of its litigation profile, the specifics of each case, advice of counsel to the extent appropriate and management’s best estimate of incurred loss as of the balance sheet date.

The following table summarizes the activity related to accrued litigation:



	Six Months Ended March 31,
	2018			2017
	(in millions)
Balance at beginning of period	$	982		$	981
Provision for uncovered legal matters	—			17
Accrual of VE territory covered litigation	1			142
Payments on legal matters	(153		)	(144		)
Balance at end of period	$	830		$	996

Accrual Summary—U.S. Covered Litigation

Visa Inc., Visa U.S.A. and Visa International are parties to certain legal proceedings that are covered by the U.S. retrospective responsibility plan, which the Company refers to as the U.S. covered litigation. See Note 2—U.S. and Europe Retrospective Responsibility Plans. An accrual for the U.S. covered litigation and a charge to the litigation provision are recorded when a loss is deemed to be probable and reasonably estimable. In making this determination, the Company evaluates available information, including but not limited to actions taken by the litigation committee. The total accrual related to the U.S. covered litigation could be either higher or lower than the escrow account balance.

The following table summarizes the activity related to U.S. covered litigation:



	Six Months Ended March 31,
	2018			2017
	(in millions)
Balance at beginning of period	$	978		$	978
Payments on U.S. covered litigation	(150		)	—
Balance at end of period	$	828		$	978

Accrual Summary—VE Territory Covered Litigation

Visa Inc., Visa International and Visa Europe are parties to certain legal proceedings that are covered by the Europe retrospective responsibility plan. Unlike the U.S. retrospective responsibility plan, the Europe retrospective responsibility plan does not have an escrow account that is used to fund settlements or judgments. The Company is entitled to recover VE territory covered losses through periodic adjustments to the conversion rates applicable to the UK&I preferred stock and Europe preferred stock. An accrual for the VE territory covered losses and a reduction to stockholders' equity will be recorded when the loss is deemed to be probable and reasonably estimable. See further discussion below under VE Territory Covered Litigation and Note 2—U.S. and Europe Retrospective Responsibility Plans.

The following table summarizes the activity related to VE territory covered litigation:



	Six Months Ended March 31,
	2018			2017
	(in millions)
Balance at beginning of period	$	1		$	2
Accrual for VE territory covered litigation	1			142
Payments on VE territory covered litigation	(2		)	(144		)
Balance at end of period	$	—		$	—

Interchange Multidistrict Litigation (MDL) – Individual Merchant Actions

A number of individual merchant actions previously filed have been settled, and remain settled. In addition, following the automatic termination of the settlement agreement with Wal-Mart Stores Inc., Visa and Wal-Mart Stores Inc. entered into a new, unconditional settlement agreement on October 31, 2017. Consequently, as of the filing date, Visa has reached settlement agreements with individual merchants representing approximately 51% of the Visa-branded payment card sales volume of merchants who opted out of the 2012 Settlement Agreement.

VE Territory Covered Litigation

UK Merchant Litigation

Since July 2013, in excess of 300 Merchants (the capitalized term "Merchant," when used in this section, means a merchant together with subsidiary/affiliate companies that are party to the same claim) have commenced proceedings against Visa Europe, Visa Inc. and Visa International relating to interchange rates in Europe. They seek damages for alleged anti-competitive conduct in relation to one or more of the following types of interchange fees for credit and debit card transactions: UK domestic, Irish domestic, other European domestic, intra-European Economic Area and/or other inter-regional. As of the filing date, Visa Europe, Visa Inc. and Visa International have settled the claims asserted by over 75 Merchants, leaving more than 200 Merchants with outstanding claims.

In November 2016, a trial commenced relating to claims filed by a number of Merchants. All of these Merchants except one settled before the trial concluded in March 2017. On November 30, 2017, the court found that Visa’s UK domestic interchange was not restrictive of competition and dismissed the remaining claim. A further judgment was published on February 23, 2018, which did not change the court's November 30, 2017 ruling but found that Visa's UK domestic interchange would not have been exemptible under applicable law if it restricted competition. The remaining Merchant lodged an appeal and the matter was listed for hearing in April 2018.

In addition, over 30 additional Merchants have threatened to commence similar proceedings. Standstill agreements have been entered into with respect to some of those Merchants' claims. While the amount of interchange being challenged could be substantial, these claims have not yet been filed and their full scope is not yet known. The Company has learned that several additional European entities have indicated that they may also bring similar claims and the Company anticipates additional claims in the future.

Other Litigation

European Commission Proceedings

Inter-regional Interchange Investigation. Visa responded in writing to the revised Supplementary Statement of Objections in November 2017 and an oral hearing was held in February 2018. Visa continues to cooperate with the European Commission (EC) in its investigation.

Further, the debit and credit commitments previously entered into to settle certain aspects of the EC's investigation have now both expired. However, the rates on which those commitments were applied remain subject to limits imposed by the European Interchange Fee Regulation.

Canadian Competition Proceedings

Merchant Litigation. The court in Quebec held a class certification hearing in November 2017 and reserved decision.

Courts in all five Canadian provinces have preliminarily approved Visa's settlement with merchant class plaintiffs, and hearings on final approval are scheduled from June through August 2018.

New Mexico Attorney General

The parties reached a settlement agreement and the case was dismissed on April 10, 2018.

EMV Chip Liability Shift

On March 11, 2018, the court denied the plaintiffs' motion for class certification without prejudice.

Kroger

On February 6, 2018, Kroger sought leave to file a second amended complaint. The parties have stipulated that the litigation, including consideration of that motion, be stayed until June 5, 2018.

Nuts for Candy

On March 6, 2018, the court denied Visa's motion for summary adjudication of Nuts for Candy's California unfair business statute claims. On April 2, 2018, Visa filed a petition for writ of mandate to the California Court of Appeal seeking to overturn the lower court's decision and stay the case while the petition is being considered.

Black Card

On December 28, 2017, Black Card LLC ("Black Card") filed a lawsuit against Visa Inc., Visa U.S.A. Inc., and certain Visa member financial institutions in the U.S. District Court for the Western District of Wisconsin. The complaint alleged that defendants conspired to impede Black Card's business in violation of Section 1 of the Sherman Act and fraudulently concealed their conduct. Black Card sought treble damages, post-judgment interest, and attorneys' fees. On February 8, 2018, Black Card voluntarily dismissed its lawsuit in the U.S. District Court for the Western District of Wisconsin without prejudice.

This action followed a lawsuit filed by Black Card in the U.S. District Court for the District of Wyoming in February 2015 relating to a contractual dispute. The District Court in Wyoming granted Visa's motions for summary judgment and the matter was dismissed. Black Card appealed this decision to the U.S. Court of Appeals for the Tenth Circuit on May 10, 2017, and the appellate court held a hearing on March 22, 2018 and reserved decision.

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2018
Accounting Policies [Abstract]
Consolidation and basis of presentation	Consolidation and basis of presentation. The accompanying unaudited consolidated financial statements include the accounts of Visa and its consolidated entities and are presented in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"). The Company consolidates its majority-owned and controlled entities, including variable interest entities ("VIEs") for which the Company is the primary beneficiary. The Company’s investments in VIEs have not been material to its consolidated financial statements as of and for the periods presented. All significant intercompany accounts and transactions are eliminated in consolidation. The accompanying unaudited consolidated financial statements are presented in accordance with the U.S. Securities and Exchange Commission (SEC) requirements for Quarterly Reports on Form 10-Q and, consequently, do not include all of the annual disclosures required by U.S. GAAP. Reference should be made to the Visa Annual Report on Form 10-K for the year ended September 30, 2017 for additional disclosures, including a summary of the Company’s significant accounting policies. In the opinion of management, the accompanying unaudited consolidated financial statements include all normal recurring adjustments necessary for a fair presentation of the Company's financial position, results of operations and cash flows for the interim periods presented.
Recently issued and adopted accounting pronouncements	Recently Issued and Adopted Accounting Pronouncements. In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of goods or services to customers. The ASU replaces existing revenue recognition guidance in U.S. GAAP. Subsequently, the FASB also issued a series of amendments to the new revenue standard. The Company will adopt the standard effective October 1, 2018, and expects to adopt the standard using the modified retrospective transition method. The Company expects that the new standard will primarily impact recognition timing for certain fixed incentives and price discounts provided to clients, and the classification of certain client incentives between contra revenues and operating expenses. The impact of the new standard to future financial results is unknowable as it is not possible to estimate the impact to the recognition of new customer contracts which may be executed in future periods. The Company has completed an assessment of its existing customer contracts through March 31, 2018. Application of the new standard to consolidated financial statements for the first two quarters of fiscal 2018 would not have resulted in a material impact. The Company will continue to assess the impact of the new standard as new customer contracts are executed going forward. In March 2016, the FASB issued ASU 2016-05, which clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815, Derivatives and Hedging, does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted the standard effective October 1, 2017. The adoption did not have a material impact on the consolidated financial statements. In March 2016, the FASB issued ASU 2016-06, which clarifies the requirements for assessing whether contingent call/put options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. An entity performing the assessment is required to assess the embedded call/put options solely in accordance with a four-step decision sequence. The Company adopted the standard effective October 1, 2017. The adoption did not have a material impact on the consolidated financial statements. In March 2016, the FASB issued ASU 2016-07, which eliminates the requirement that an entity retroactively adopt the equity method of accounting if an investment qualifies for use of the equity method as a result of an increase in the level of ownership or degree of influence. The equity method investor is required to add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted the standard effective October 1, 2017. The adoption did not have a material impact on the consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, which allows a reclassification from accumulated other comprehensive income to retained earnings for adjustments to tax effects that were originally recorded in other comprehensive income due to changes in the U.S. federal corporate income tax rate resulting from the enactment of the U.S. tax reform legislation, commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Company will adopt the standard effective October 1, 2019. The adoption is not expected to have a material impact on the consolidated financial statements. In March 2018, the FASB issued ASU 2018-05 to insert the SEC's interpretive guidance from Staff Accounting Bulletin No. 118 into the income tax accounting codification under U.S. GAAP. The ASU permits companies to use provisional amounts for certain income tax effects of the Tax Act during a one-year measurement period. The provisional accounting impacts for the Company may change in future reporting periods until the accounting analysis is finalized, which will occur no later than the first quarter of fiscal 2019.

U.S. and Europe Retrospective Responsibility Plans (Tables)

6 Months Ended

Mar. 31, 2018

Retrospective Responsibility Plan [Abstract]

Schedule of Activities Related to Territory Covered Losses and Right to Recover for Covered Losses

The following table sets forth the activities related to VE territory covered losses in preferred stock and "right to recover for covered losses" within equity during the six months ended March 31, 2018. VE territory covered losses incurred reflect settlements with merchants and additional legal costs. See Note 11—Legal Matters.



	Preferred Stock						Right to Recover for Covered Losses
	UK&I			Europe			Right to Recover for Covered Losses
	(in millions)
Balance as of September 30, 2017	$	2,326		$	3,200		$	(52	)
VE territory covered losses incurred	—			—			(4		)
Recovery through conversion rate adjustment	(31		)	(19		)	50
Balance as of March 31, 2018	$	2,295		$	3,181		$	(6	)

Schedule of As-converted and Book Value of Preferred Stock Available to Recover Europe Covered Losses

The following table sets forth the as-converted value of the preferred stock available to recover VE territory covered losses compared to the book value of preferred shares recorded in stockholders' equity within the Company's unaudited consolidated balance sheet as of March 31, 2018 and September 30, 2017.⁽¹⁾



	March 31, 2018						September 30, 2017
	As-Converted Value of Preferred Stock⁽²⁾			Book Value of Preferred Stock			As-Converted Value of Preferred Stock⁽³⁾			Book Value of Preferred Stock
	(in millions)
UK&I preferred stock	$	3,847		$	2,295		$	3,414		$	2,326
Europe preferred stock	5,246			3,181			4,634			3,200
Total	9,093			5,476			8,048			5,526
Less: right to recover for covered losses	(6		)	(6		)	(52		)	(52		)
Total recovery for covered losses available	$	9,087		$	5,470		$	7,996		$	5,474


⁽¹⁾	Figures in the table may not recalculate exactly due to rounding. As-converted and book values are based on unrounded numbers.

⁽²⁾

The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of March 31, 2018; (b)12.966 and 13.893, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of March 31, 2018, respectively; and (c) $119.62, Visa's class A common stock closing stock price as of March 31, 2018.

⁽³⁾

The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of September 30, 2017; (b)13.077 and 13.948, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of September 30, 2017, respectively; and (c) $105.24, Visa's class A common stock closing stock price as of September 30, 2017.

Fair Value Measurements and Investments (Tables)

6 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis



	Fair Value Measurements Using Inputs Considered as
	Level 1				Level 2
	March 31, 2018		September 30, 2017		March 31, 2018		September 30, 2017
	(in millions)
Assets
Cash equivalents and restricted cash:
Money market funds	$	6,141	$	5,935
U.S. government-sponsored debt securities					$	272	$	2,870
Investment securities, trading:
Equity securities	94		82
Investment securities, available-for-sale:
U.S. government-sponsored debt securities					3,641		3,663
U.S. Treasury securities	2,284		1,621
Equity securities	160		124
Prepaid and other current assets:
Foreign exchange derivative instruments					12		18
Total	$	8,679	$	7,762	$	3,925	$	6,551
Liabilities
Accrued liabilities:
Foreign exchange derivative instruments					$	82	$	98
Total	$	—	$	—	$	82	$	98

Schedule of Long-term Debt Instruments

The following table presents the carrying amount and estimated fair value of the Company’s debt in order of maturity:



	March 31, 2018				September 30, 2017
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
	(in millions)
1.20% Senior Notes due December 2017	$	—	$	—	$	1,749	$	1,751
2.20% Senior Notes due December 2020	2,992		2,953		2,990		3,031
2.15% Senior Notes due September 2022	994		964		993		997
2.80% Senior Notes due December 2022	2,241		2,221		2,240		2,301
3.15% Senior Notes due December 2025	3,969		3,923		3,967		4,098
2.75% Senior Notes due September 2027	740		707		740		737
4.15% Senior Notes due December 2035	1,486		1,597		1,485		1,637
4.30% Senior Notes due December 2045	3,462		3,754		3,463		3,873
3.65% Senior Notes due September 2047	740		729		740		746
Total	$	16,624	$	16,848	$	18,367	$	19,171

Settlement Guarantee Management [Abstract]

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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+ Details

Debt (Tables)

6 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Schedule of Debt

The Company had outstanding debt as follows:



	March 31, 2018							September 30, 2017
	Principal Amount		Unamortized Discounts and Debt Issuance Costs			Carrying Amount		Principal Amount		Unamortized Discounts and Debt Issuance Costs			Carrying Amount		Effective Interest Rate
	(in millions, except percentages)
1.20% Senior Notes due December 2017 (the "2017 Notes")	$	—	$	—		$	—	$	1,750	$	(1	)	$	1,749	1.37	%
Total current maturities of long-term debt	—		—			—		1,750		(1		)	1,749

2.20% Senior Notes due December 2020	3,000		(8		)	2,992		3,000		(10		)	2,990		2.30	%
2.15% Senior Notes due September 2022	1,000		(6		)	994		1,000		(7		)	993		2.30	%
2.80% Senior Notes due December 2022	2,250		(9		)	2,241		2,250		(10		)	2,240		2.89	%
3.15% Senior Notes due December 2025	4,000		(31		)	3,969		4,000		(33		)	3,967		3.26	%
2.75% Senior Notes due September 2027	750		(10		)	740		750		(10		)	740		2.91	%
4.15% Senior Notes due December 2035	1,500		(14		)	1,486		1,500		(15		)	1,485		4.23	%
4.30% Senior Notes due December 2045	3,500		(38		)	3,462		3,500		(37		)	3,463		4.37	%
3.65% Senior Notes due September 2047	750		(10		)	740		750		(10		)	740		3.73	%
Total long-term debt	16,750		(126		)	16,624		16,750		(132		)	16,618

Total debt	$	16,750	$	(126	)	$	16,624	$	18,500	$	(133	)	$	18,367

Settlement Guarantee Management (Tables)

6 Months Ended

Mar. 31, 2018

Schedule of Customer Collateral

The Company maintained collateral as follows:



	March 31, 2018		September 30, 2017
	(in millions)
Cash equivalents⁽¹⁾	$	1,684	$	1,490
Pledged securities at market value	166		167
Letters of credit	1,351		1,316
Guarantees	653		941
Total	$	3,854	$	3,914


⁽¹⁾	Cash collateral held by Visa Europe is not included on the Company's consolidated balance sheets as its clients retain beneficial ownership and the cash is only accessible to the Company in the event of default by the client on its settlement obligations.

Stockholders' Equity (Tables)

6 Months Ended

Mar. 31, 2018

Stockholders' Equity Note [Abstract]

Schedule of Stock by Class

The number of shares of each series and class and the number of shares of class A common stock on an as-converted basis at March 31, 2018, are as follows:



(in millions, except conversion rates)	Shares Outstanding	Conversion Rate Into Class A Common Stock		As-converted Class A Common Stock⁽¹⁾
UK&I preferred stock	2	12.9660		32
Europe preferred stock	3	13.8930		44
Class A common stock⁽²⁾	1,790	—		1,790
Class B common stock	245	1.6483	⁽³⁾	405
Class C common stock	12	4.0000		49
Total				2,320


⁽¹⁾	Figures in the table may not recalculate exactly due to rounding. As-converted class A common stock is calculated based on unrounded numbers.


⁽²⁾	Class A common stock shares outstanding exclude repurchases traded but not yet settled on or before March 31, 2018.


⁽³⁾	The class B to class A common stock conversion rate is presented on a rounded basis. Conversion calculations for dividend payments are based on a conversion rate rounded to the tenth decimal.

Share Repurchase Program Disclosure

The following table presents share repurchases in the open market.⁽¹⁾



(in millions, except per share data)	Three Months Ended March 31, 2018		Six Months Ended March 31, 2018
Shares repurchased in the open market⁽²⁾	17		33
Average repurchase price per share⁽³⁾	$	120.26	$	115.41
Total cost	$	2,072	$	3,850


⁽¹⁾	Shares repurchased in the open market reflect repurchases settled during the three and six months ended March 31, 2018. These amounts include repurchases traded but not yet settled on or before September 30, 2017 for the six months, or December 31, 2017 for the three months, and exclude repurchases traded but not yet settled on or before March 31, 2018.


⁽²⁾	All shares repurchased in the open market have been retired and constitute authorized but unissued shares.


⁽³⁾	Figures in the table may not recalculate exactly due to rounding. Average repurchase price per share is calculated based on unrounded numbers.

Effect of VE Territory Covered Losses Recovery on the Company Repurchasing its Common Stock

The following table presents as-converted UK&I and Europe preferred stock, after the Company recovered VE territory covered losses through conversion rate adjustments, for the six months ended March 31, 2018. The Company did not have any adjustment recorded for UK&I and Europe preferred stock during the three months ended March 31, 2018.



	Six Months Ended March 31, 2018
(in millions, except per share data)	UK&I Preferred Stock		Europe Preferred Stock
Reduction in equivalent number of shares of class A common stock⁽¹⁾	—		—
Effective price per share⁽²⁾	$	111.32	$	111.32
Recovery through conversion rate adjustment	$	31	$	19


⁽¹⁾	The reduction in equivalent number of shares of class A common stock was less than one million shares for both series of preferred stock.


⁽²⁾	Effective price per share is calculated using the volume-weighted average price of the Company's class A common stock over a pricing period in accordance with the Company's current certificates of designations for its series B and C convertible participating preferred stock.

Schedule of Earnings Per Share, Basic and Diluted

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

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+ Details

Earnings Per Share (Tables)

6 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

The following table presents earnings per share for the three months ended March 31, 2018.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	2,007	1,798	$	1.12	$	2,605	2,337	⁽³⁾	$	1.11
Class B common stock	452		245	$	1.84	$	451	245		$	1.84
Class C common stock	55		12	$	4.46	$	55	12		$	4.46
Participating securities⁽⁴⁾	91		Not presented	Not presented		$	91	Not presented		Not presented
Net income	$	2,605

The following table presents earnings per share for the six months ended March 31, 2018.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	3,952	1,805	$	2.19	$	5,127	2,345	⁽³⁾	$	2.19
Class B common stock	886		245	$	3.61	$	885	245		$	3.60
Class C common stock	110		13	$	8.76	$	109	13		$	8.74
Participating securities⁽⁴⁾	179		Not presented	Not presented		$	178	Not presented		Not presented
Net income	$	5,127

The following table presents earnings per share for the three months ended March 31, 2017.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	332	1,854	$	0.18	$	430	2,406	⁽³⁾	$	0.18
Class B common stock	73		245	$	0.30	$	72	245		$	0.29
Class C common stock	10		15	$	0.72	$	10	15		$	0.72
Participating securities⁽⁴⁾	15		Not presented	Not presented		$	15	Not presented		Not presented
Net income	$	430

The following table presents earnings per share for the six months ended March 31, 2017.⁽¹⁾



	Basic Earnings Per Share					Diluted Earnings Per Share
	(in millions, except per share data)
	Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)	Earnings per Share = (A)/(B)		Income Allocation (A)⁽²⁾		Weighted- Average Shares Outstanding (B)		Earnings per Share = (A)/(B)
Class A common stock	$	1,928	1,857	$	1.04	$	2,500	2,413	⁽³⁾	$	1.04
Class B common stock	420		245	$	1.71	$	419	245		$	1.71
Class C common stock	65		16	$	4.15	$	65	16		$	4.14
Participating securities⁽⁴⁾	87		Not presented	Not presented		$	87	Not presented		Not presented
Net income	$	2,500


⁽¹⁾	Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.

⁽²⁾

Net income is allocated based on proportional ownership on an as-converted basis. The weighted-average number of shares of as-converted class B common stock used in the income allocation was 405 million for the three and six months ended March 31, 2018 and 2017. The weighted-average number of shares of as-converted class C common stock used in the income allocation was 49 million and 50 million for the three and six months ended March 31, 2018, respectively, and 58 million and 63 million for the three and six months ended March 31, 2017, respectively. The weighted-average number of shares of preferred stock, included within participating securities, was 32 million of as-converted UK&I preferred stock for the three and six months ended March 31, 2018, 34 million of as-converted UK&I preferred stock for three and six months ended March 31, 2017 and 44 million of as-converted Europe preferred stock for the three and six months ended March 31, 2018 and 2017.

⁽³⁾

Weighted-average diluted shares outstanding are calculated on an as-converted basis, and include incremental common stock equivalents, as calculated under the treasury stock method. The computation includes approximately 4 million common stock equivalents for the three and six months ended March 31, 2018 and 5 million common stock equivalents for the three and six months ended March 31, 2017, because their effect would be dilutive. The computation excludes 2 million of common stock equivalents for the three and six months ended March 31, 2018 and 3 million for the three and six months ended March 31, 2017, because their effect would have been anti-dilutive.

⁽⁴⁾

Participating securities include preferred stock outstanding and unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents, such as the Company's UK&I and Europe preferred stock, restricted stock awards, restricted stock units and earned performance-based shares. Participating securities' income is allocated based on the weighted-average number of shares of as-converted stock.

Share-based Compensation (Tables)

6 Months Ended

Mar. 31, 2018

Share-based Compensation [Abstract]

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award

The Company granted the following equity awards to employees and non-employee directors under the 2007 Equity Incentive Compensation Plan during the six months ended March 31, 2018:



	Granted	Weighted-Average Grant Date Fair Value		Weighted-Average Exercise Price
Non-qualified stock options	1,622,760	$	17.88	$	109.82
Restricted stock units ("RSUs")	2,714,648	$	110.19
Performance-based shares⁽¹⁾	641,498	$	120.11


⁽¹⁾	Represents the maximum number of performance-based shares which could be earned.

Legal Matters (Tables) - USD ($)
$ in Millions

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Loss Contingencies [Line Items]

Schedule of Loss Contingencies by Contingency

The following table summarizes the activity related to accrued litigation:



	Six Months Ended March 31,
	2018			2017
	(in millions)
Balance at beginning of period	$	982		$	981
Provision for uncovered legal matters	—			17
Accrual of VE territory covered litigation	1			142
Payments on legal matters	(153		)	(144		)
Balance at end of period	$	830		$	996

Loss Contingency Accrual [Roll Forward]

Balance at beginning of period

$ 982

$ 981

Balance at end of period

$ 830

996

U.S. Covered Litigation

Loss Contingencies [Line Items]

Schedule of Loss Contingencies by Contingency

The following table summarizes the activity related to U.S. covered litigation:



	Six Months Ended March 31,
	2018			2017
	(in millions)
Balance at beginning of period	$	978		$	978
Payments on U.S. covered litigation	(150		)	—
Balance at end of period	$	828		$	978

Loss Contingency Accrual [Roll Forward]

Balance at beginning of period

$ 978

Balance at end of period

$ 828

978

VE Territory Covered Litigation

Loss Contingencies [Line Items]

Schedule of Loss Contingencies by Contingency

The following table summarizes the activity related to VE territory covered litigation:



	Six Months Ended March 31,
	2018			2017
	(in millions)
Balance at beginning of period	$	1		$	2
Accrual for VE territory covered litigation	1			142
Payments on VE territory covered litigation	(2		)	(144		)
Balance at end of period	$	—		$	—

Loss Contingency Accrual [Roll Forward]

Balance at beginning of period

$ 1

2

Provision for legal matters

1

142

Balance at end of period

$ 0

Tabular disclosure of the loss contingencies that were reported in the period or disclosed as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14472-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12021-110248

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14453-108349

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12053-110248

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14394-108349

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14615-108349

+ Details

Summary of Significant Accounting Policies (Details)	Mar. 31, 2018 country
Accounting Policies [Abstract]
Number of countries in which entity operates (more than)	200

U.S. and Europe Retrospective Responsibility Plans (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2017
Retrospective Responsibility Plan [Abstract]
Escrow account	$ 884		$ 1,031
Payments for Legal Settlements	$ (150)	$ 0

U.S. and Europe Retrospective Responsibility Plans - Preferred Stock Rollforward (Details)
€ in Millions, $ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

EUR (€)

Mar. 31, 2018

USD ($)

Sep. 30, 2017

VE territory covered loss, maximum amount of loss to allow adjustment of conversion rate during six-month period | €

€ 20

Preferred Stock and Right to Recover for Covered Losses [Roll Forward]

$ 50

Preferred stock, beginning

5,526

^[1]

Right to recover for covered losses, beginning

50

Preferred stock, ending

5,476

^[1]

52

^[1]

VE territory covered losses incurred

(4)

Right to recover for covered losses, ending

6

^[1]

$ (31)

Preferred Stock and Right to Recover for Covered Losses [Roll Forward]

12.966

13.077

Preferred stock, beginning

$ 2,326

^[1]

(31)

Preferred stock, ending

2,295

^[1]

$ (19)

Preferred Stock and Right to Recover for Covered Losses [Roll Forward]

13.893

13.948

Preferred stock, beginning

$ 3,200

^[1]

(19)

Preferred stock, ending

$ 3,181

^[1]

[1]	Figures in the table may not recalculate exactly due to rounding. As-converted and book values are based on unrounded numbers.

U.S. and Europe Retrospective Responsibility Plans - Preferred Stock (Details)
$ / shares in Units, shares in Millions, $ in Millions

Mar. 31, 2018

USD ($)

$ / shares

shares

Sep. 30, 2017

USD ($)

$ / shares

shares

As-converted value of preferred stock

^[1]

$ 9,093

^[2]

$ 8,048

^[3]

Book Value of Preferred stock

^[1]

5,476

5,526

Right to recover for covered losses

^[1]

(6)

(52)

Total recovery for covered losses available, as converted

^[1]

9,087

7,996

Total recovery for covered losses available, book value

^[1]

$ 5,470

5,474

Closing stock price | $ / shares

$ 119.62

As-converted value of preferred stock

^[1]

$ 3,847

^[2]

3,414

^[3]

Book Value of Preferred stock

^[1]

$ 2,295

$ 2,326

Preferred stock, shares outstanding | shares

2

12.966

13.077

As-converted value of preferred stock

^[1]

$ 5,246

^[2]

$ 4,634

^[3]

Book Value of Preferred stock

^[1]

$ 3,181

$ 3,200

Preferred stock, shares outstanding | shares

3

13.893

13.948

Closing stock price | $ / shares

$ 105.24

[1]	Figures in the table may not recalculate exactly due to rounding. As-converted and book values are based on unrounded numbers.
[2]	The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of March 31, 2018; (b)12.966 and 13.893, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of March 31, 2018, respectively; and (c) $119.62, Visa's class A common stock closing stock price as of March 31, 2018.
[3]	The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of March 31, 2018; (b)12.966 and 13.893, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of March 31, 2018, respectively; and (c) $119.62, Visa's class A common stock closing stock price as of March 31, 2018.(3) The as-converted value of preferred stock is calculated as the product of: (a) 2 million and 3 million shares of the UK&I and Europe preferred stock outstanding, respectively, as of September 30, 2017; (b)13.077 and 13.948, the class A common stock conversion rate applicable to the UK&I and Europe preferred stock as of September 30, 2017, respectively; and (c) $105.24, Visa's class A common stock closing stock price as of September 30, 2017.

Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Assets
Investment securities, trading:	$ 94	$ 82
Liabilities
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	0
Fair Value, Measurements, Recurring \| Level 1
Assets
Total	8,679	7,762
Liabilities
Total	0	0
Fair Value, Measurements, Recurring \| Level 2
Assets
Total	3,925	6,551
Liabilities
Total	82	98
Cash equivalents and restricted cash: \| Fair Value, Measurements, Recurring \| Level 1 \| Money market funds
Assets
Cash equivalents and restricted cash:	6,141	5,935
Cash equivalents and restricted cash: \| Fair Value, Measurements, Recurring \| Level 2 \| U.S. government-sponsored debt securities
Assets
Cash equivalents and restricted cash:	272	2,870
Investment securities, trading: \| Fair Value, Measurements, Recurring \| Level 1 \| Equity securities
Assets
Investment securities, trading:	94	82
Investment securities, available-for-sale: \| Fair Value, Measurements, Recurring \| Level 1 \| Equity securities
Assets
Investment securities, available-for-sale:	160	124
Investment securities, available-for-sale: \| Fair Value, Measurements, Recurring \| Level 1 \| U.S. Treasury securities
Assets
Investment securities, available-for-sale:	2,284	1,621
Investment securities, available-for-sale: \| Fair Value, Measurements, Recurring \| Level 2 \| U.S. government-sponsored debt securities
Assets
Investment securities, available-for-sale:	3,641	3,663
Prepaid and other current assets: \| Fair Value, Measurements, Recurring \| Level 2 \| Foreign exchange derivative instruments
Assets
Prepaid and other current assets:	12	18
Foreign exchange derivative instruments \| Accrued liabilities: \| Fair Value, Measurements, Recurring \| Level 2
Liabilities
Accrued liabilities:	$ 82	$ 98

Fair Value Measurements and Investments - Additional Information (Detail) - USD ($)	6 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable equity investments	$ 109,000,000	$ 94,000,000
Available-for-sale securities, gross unrealized gains	156,000,000	120,000,000
Available-for-sale securities, gross unrealized losses	$ 18,000,000	$ 4,000,000
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, stated maturities	1 year
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, stated maturities	2 years

Fair Value Measurements and Investments Fair Value Measurements and Investments - Fair Value of Debt (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
2017 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.20%
2020 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.20%
September 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.15%
2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.80%
2025 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.15%
2027 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.75%
2035 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.15%
2045 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.30%
2047 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.65%
Senior Notes \| 2017 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.20%
Senior Notes \| 2020 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.20%
Senior Notes \| September 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.15%
Senior Notes \| 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.80%
Senior Notes \| 2025 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.15%
Senior Notes \| 2027 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.75%
Senior Notes \| 2035 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.15%
Senior Notes \| 2045 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.30%
Senior Notes \| 2047 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.65%
Senior Notes \| Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	$ 16,624	$ 18,367
Senior Notes \| Carrying Amount \| 2017 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	0	1,749
Senior Notes \| Carrying Amount \| 2020 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	2,992	2,990
Senior Notes \| Carrying Amount \| September 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	994	993
Senior Notes \| Carrying Amount \| 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	2,241	2,240
Senior Notes \| Carrying Amount \| 2025 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	3,969	3,967
Senior Notes \| Carrying Amount \| 2027 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	740	740
Senior Notes \| Carrying Amount \| 2035 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	1,486	1,485
Senior Notes \| Carrying Amount \| 2045 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	3,462	3,463
Senior Notes \| Carrying Amount \| 2047 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	740	740
Senior Notes \| Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	16,848	19,171
Senior Notes \| Estimated Fair Value \| 2017 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	0	1,751
Senior Notes \| Estimated Fair Value \| 2020 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	2,953	3,031
Senior Notes \| Estimated Fair Value \| September 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	964	997
Senior Notes \| Estimated Fair Value \| 2022 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	2,221	2,301
Senior Notes \| Estimated Fair Value \| 2025 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	3,923	4,098
Senior Notes \| Estimated Fair Value \| 2027 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	707	737
Senior Notes \| Estimated Fair Value \| 2035 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	1,597	1,637
Senior Notes \| Estimated Fair Value \| 2045 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	3,754	3,873
Senior Notes \| Estimated Fair Value \| 2047 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	$ 729	$ 746

Debt - Debt (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Long-term Debt, Current Maturities	$ 0	$ 1,749
Carrying Amount, noncurrent	$ 16,624	$ 16,618
2017 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.20%
2020 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.20%
September 2022 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.15%
2022 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.80%
2025 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.15%
2027 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.75%
2035 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.15%
2045 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.30%
2047 Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.65%
Senior Notes
Debt Instrument [Line Items]
Principal Amount, current maturities	$ 0	$ 1,750
Unamortized Discounts and Debt Issuance Costs, current maturities	0	(1)
Long-term Debt, Current Maturities	0	1,749
Principal Amount, noncurrent	16,750	16,750
Unamortized Discounts and Debt Issuance Costs, noncurrent	(126)	(132)
Carrying Amount, noncurrent	16,624	16,618
Total debt, principal	16,750	18,500
Unamortized Discounts and Debt Issuance Costs	(126)	(133)
Carrying Amount	16,624	18,367
Senior Notes \| 2017 Notes
Debt Instrument [Line Items]
Principal Amount, current maturities	0	1,750
Unamortized Discounts and Debt Issuance Costs, current maturities	0	(1)
Long-term Debt, Current Maturities	$ 0	$ 1,749
Effective Interest Rate (percent)	1.37%
Debt Instrument, Interest Rate, Stated Percentage		1.20%
Senior Notes \| 2020 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 3,000	$ 3,000
Unamortized Discounts and Debt Issuance Costs, noncurrent	(8)	(10)
Carrying Amount, noncurrent	$ 2,992	2,990
Effective Interest Rate (percent)	2.30%
Debt Instrument, Interest Rate, Stated Percentage	2.20%
Senior Notes \| September 2022 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 1,000	1,000
Unamortized Discounts and Debt Issuance Costs, noncurrent	(6)	(7)
Carrying Amount, noncurrent	$ 994	993
Effective Interest Rate (percent)	2.30%
Debt Instrument, Interest Rate, Stated Percentage	2.15%
Senior Notes \| 2022 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 2,250	2,250
Unamortized Discounts and Debt Issuance Costs, noncurrent	(9)	(10)
Carrying Amount, noncurrent	$ 2,241	2,240
Effective Interest Rate (percent)	2.89%
Debt Instrument, Interest Rate, Stated Percentage	2.80%
Senior Notes \| 2025 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 4,000	4,000
Unamortized Discounts and Debt Issuance Costs, noncurrent	(31)	(33)
Carrying Amount, noncurrent	$ 3,969	3,967
Effective Interest Rate (percent)	3.26%
Debt Instrument, Interest Rate, Stated Percentage	3.15%
Senior Notes \| 2027 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 750	750
Unamortized Discounts and Debt Issuance Costs, noncurrent	(10)	(10)
Carrying Amount, noncurrent	$ 740	740
Effective Interest Rate (percent)	2.91%
Debt Instrument, Interest Rate, Stated Percentage	2.75%
Senior Notes \| 2035 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 1,500	1,500
Unamortized Discounts and Debt Issuance Costs, noncurrent	(14)	(15)
Carrying Amount, noncurrent	$ 1,486	1,485
Effective Interest Rate (percent)	4.23%
Debt Instrument, Interest Rate, Stated Percentage	4.15%
Senior Notes \| 2045 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 3,500	3,500
Unamortized Discounts and Debt Issuance Costs, noncurrent	(38)	(37)
Carrying Amount, noncurrent	$ 3,462	3,463
Effective Interest Rate (percent)	4.37%
Debt Instrument, Interest Rate, Stated Percentage	4.30%
Senior Notes \| 2047 Notes
Debt Instrument [Line Items]
Principal Amount, noncurrent	$ 750	750
Unamortized Discounts and Debt Issuance Costs, noncurrent	(10)	(10)
Carrying Amount, noncurrent	$ 740	$ 740
Effective Interest Rate (percent)	3.73%
Debt Instrument, Interest Rate, Stated Percentage	3.65%

Debt - Narrative (Details) - Senior Notes - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Oct. 11, 2017	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Interest expense		$ 137	$ 125	$ 275	$ 250
2017 Notes
Debt Instrument [Line Items]
Repayments of Debt	$ 1,750
Gain (Loss) on Extinguishment of Debt				$ (1)

Settlement Guarantee Management - Additional Information (Detail) - USD ($) $ in Billions	3 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Settlement Guarantee Management [Abstract]
Estimated Maximum Settlement Exposure	$ 72.7	$ 67.7
Covered settlement exposure	$ 2.7	$ 2.8

Collateral (Detail) - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

Settlement Guarantee Management [Abstract]

Cash equivalents

^[1]

$ 1,684

$ 1,490

Pledged securities at market value

166

167

Letters of credit

1,351

1,316

Guarantees

653

941

Total

$ 3,854

$ 3,914

[1]	Cash collateral held by Visa Europe is not included on the Company's consolidated balance sheets as its clients retain beneficial ownership and the cash is only accessible to the Company in the event of default by the client on its settlement obligations.

Components of Net Periodic Benefit Cost (Detail) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	8	9	16	18
Expected return on plan assets	(18)	(17)	(35)	(35)
Amortization of actuarial loss	0	4	0	8
Settlement loss	0	11	0	13
Total net periodic benefit cost	(10)	7	(19)	4
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	3
Interest cost	3	2	6	5
Expected return on plan assets	(5)	(4)	(10)	(8)
Amortization of actuarial loss	0	1	0	1
Settlement loss	0	0	0	0
Total net periodic benefit cost	$ (1)	$ 0	$ (2)	$ 1

Stockholders' Equity - Number of Shares of Class A Common Shares Outstanding on an As-Converted Basis (Detail)
shares in Millions

Mar. 31, 2018

shares

Sep. 30, 2017

shares

Schedule of Common Stock as Converted [Line Items]

2,320

Schedule of Common Stock as Converted [Line Items]

Preferred stock, conversion rate into Class A Common Stock

2

12.966

13.077

^[1]

32

Schedule of Common Stock as Converted [Line Items]

Preferred stock, conversion rate into Class A Common Stock

3

13.893

13.948

^[1]

44

Schedule of Common Stock as Converted [Line Items]

1,790

^[2]

1,818

^[1],[2]

1,790

Schedule of Common Stock as Converted [Line Items]

Common stock, conversion rate into Class A Common Stock

245

^[3]

1.6483

^[1]

405

Schedule of Common Stock as Converted [Line Items]

Common stock, conversion rate into Class A Common Stock

12

13

4

Stockholders Equity Note [Line Items]

^[1]

49

[1]	Figures in the table may not recalculate exactly due to rounding. As-converted class A common stock is calculated based on unrounded numbers.
[2]	Class A common stock shares outstanding exclude repurchases traded but not yet settled on or before March 31, 2018.
[3]	The class B to class A common stock conversion rate is presented on a rounded basis. Conversion calculations for dividend payments are based on a conversion rate rounded to the tenth decimal.

Stockholders' Equity - Additional Information (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Apr. 17, 2018

Jan. 30, 2018

Stock Repurchased and Retired During Period, Shares

^[1],[2]

17

33

Stock Repurchased and Retired During Period, Value

^[2]

$ 2,072

$ 3,850

Stock Repurchase Program, Authorized Amount

50

$ 7,500

Stock Repurchase Remaining Authorized Amount

7,500

Dividends, Cash

$ 490

$ 948

Stockholders Equity Note [Line Items]

Reduction In As-Converted Stock, Shares

34

Reduction in As-Converted Stock, Average Price Per Share

$ 115.36

Subsequent Event | Class A common stock

Stockholders Equity Note [Line Items]

Dividends Payable, Amount Per Share

$ 0.21

[1]	All shares repurchased in the open market have been retired and constitute authorized but unissued shares.
[2]	Shares repurchased in the open market reflect repurchases settled during the three and six months ended March 31, 2018. These amounts include repurchases traded but not yet settled on or before September 30, 2017 for the six months, or December 31, 2017 for the three months, and exclude repurchases traded but not yet settled on or before March 31, 2018.

Stockholders' Equity - Share Repurchases in the Open Market (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Stockholders' Equity Note [Abstract]

Shares repurchased in the open market

^[1],[2]

17

33

Average repurchase price per share

^[2],[3]

$ 120.26

$ 115.41

Total cost

^[2]

$ 2,072

$ 3,850

[1]	All shares repurchased in the open market have been retired and constitute authorized but unissued shares.
[2]	Shares repurchased in the open market reflect repurchases settled during the three and six months ended March 31, 2018. These amounts include repurchases traded but not yet settled on or before September 30, 2017 for the six months, or December 31, 2017 for the three months, and exclude repurchases traded but not yet settled on or before March 31, 2018.
[3]	Figures in the table may not recalculate exactly due to rounding. Average repurchase price per share is calculated based on unrounded numbers.

Stockholders' Equity Effect of VE Territory Covered Losses Recovery on the Company Repurchasing its Common Stock (Details)
$ / shares in Units, shares in Millions, $ in Millions

6 Months Ended

Mar. 31, 2018

USD ($)

$ / shares

shares

Conversion of Stock [Line Items]

$ (50)

Reduction in equivalent number of shares of class A common stock | shares

Conversion of Stock [Line Items]

0

^[1]

Effective price per share (in USD per share) | $ / shares

$ 111.32

^[2]

$ 31

Reduction in equivalent number of shares of class A common stock | shares

Conversion of Stock [Line Items]

0

^[1]

Effective price per share (in USD per share) | $ / shares

$ 111.32

^[2]

Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]

$ 19

[1]	(1) The reduction in equivalent number of shares of class A common stock was less than one million shares for both series of preferred stock
[2]	(2) Effective price per share is calculated using the volume-weighted average price of the Company's class A common stock over a pricing period in accordance with the Company's current certificates of designations for its series B and C convertible participating preferred stock.

Basic and Diluted Earnings Per Share (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Net income

$ 2,605

$ 430

$ 5,127

$ 2,500

Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]

Weighted- Average Shares Outstanding - Basic

^[1]

$ 2,007

$ 332

$ 3,952

$ 1,928

1,798

1,854

1,805

1,857

Earnings per Share - Basic

^[2]

$ 1.12

$ 0.18

$ 2.19

$ 1.04

Weighted- Average Shares Outstanding - Diluted

^[1]

$ 2,605

$ 430

$ 5,127

$ 2,500

^[3]

2,337

2,406

2,345

2,413

Earnings per Share - Diluted

^[2]

$ 1.11

$ 0.18

$ 2.19

$ 1.04

Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]

Weighted- Average Shares Outstanding - Basic

^[1]

$ 452

$ 73

$ 886

$ 420

245

Earnings per Share - Basic

^[2]

$ 1.84

$ 0.30

$ 3.61

$ 1.71

Weighted- Average Shares Outstanding - Diluted

^[1]

$ 451

$ 72

$ 885

$ 419

245

Earnings per Share - Diluted

^[2]

$ 1.84

$ 0.29

$ 3.60

$ 1.71

Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]

Weighted- Average Shares Outstanding - Basic

^[1]

$ 55

$ 10

$ 110

$ 65

12

15

13

16

Earnings per Share - Basic

^[2]

$ 4.46

$ 0.72

$ 8.76

$ 4.15

Weighted- Average Shares Outstanding - Diluted

^[1]

$ 55

$ 10

$ 109

$ 65

12

15

13

16

Earnings per Share - Diluted

^[2]

$ 4.46

$ 0.72

$ 8.74

$ 4.14

Participating securities

Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]

^[1],[4]

$ 91

$ 15

$ 179

$ 87