How Credit Card Transactions Work: Authorization to Settlement

The short answer

Direct answerA credit card transaction usually begins with an authentication check and an authorization request. The issuer sends an approval or decline through the network and merchant-side providers. If the merchant completes the sale, transaction data is captured and cleared, financial institutions settle their obligations, the merchant is funded, and the issuer posts the purchase to the cardholder's account.^[1]

The fastest part is the decision message. The slower parts reconcile records, calculate obligations, move funds between institutions, fund the merchant, and update the cardholder's account. That is why an approved transaction can remain pending, change amount, disappear after a reversal, or post days later.

Generalized flowThis page shows a common open-loop card model, not a universal wiring diagram. Closed-loop networks, domestic systems, wallets, payment facilitators, processors, merchants, and issuers can combine roles or use different names and timing. A network-specific rule is identified as such.

Who participates

A company can perform more than one job, so the role matters more than the logo. The U.S. Office of the Comptroller of the Currency treats merchant processing as distinct from issuing and notes that banks can outsource processing functions to third parties.^[2]

Roles in a generalized card transaction. Actual contracts and technical paths vary.
Participant	Primary job in the flow	Important boundary
Cardholder	Presents a card, account number, or token and later repays the issuer.	Does not usually pay the merchant directly in the authorization step.
Merchant	Accepts the credential, supplies the good or service, and submits the transaction.	Does not usually provide the revolving credit.
Gateway	Collects and transmits checkout data, especially in e-commerce.	May be bundled with a processor, but is not automatically the acquirer.
Processor	Handles transaction messages or records for a merchant, acquirer, issuer, or program.	"Processor" is incomplete unless the party it serves is named.
Acquirer	Provides or sponsors merchant acceptance and receives settlement on the merchant side.	Is on the merchant side, not the cardholder-credit side.
Payment network	Routes messages and applies network operating, clearing, and settlement rules.	Usually does not set the cardholder's individual credit limit.
Issuer	Provides the account, evaluates authorization, posts activity, bills the cardholder, and receives repayment.	Is not necessarily the brand most prominent on the card.
Wallet or token service	Can provision a constrained substitute credential and support device authentication.	The token is not a separate pool of money or a new credit account.

Information moves before money

At checkout, the system first asks for a decision. The U.S. Treasury's Card Acquiring Service describes an authorization request moving from the accepting merchant or agency to an acquirer or processor, through a card network, and to the issuing bank. An approval or decline returns to the acceptance point.^[1]

1 · CheckoutCredential presentedCard, account data, or a wallet token enters the merchant environment.

2 · Merchant sideRequest preparedA gateway or processor adds amount, merchant, terminal, and transaction context.

3 · AcceptanceAcquirer routesThe merchant-side institution or processor sends the request onward.

4 · NetworkMessage switchedThe network applies routing and network controls.

5 · AccountIssuer decidesAn approval, decline, or request for more action returns along the path.

No final sale proceeds move in this diagram. An approval says the transaction may proceed under the information available at that moment. It is not proof of final clearing, settlement, merchant funding, or account posting.

AuthenticationDoes the person, device, or credential appear legitimate?

AuthorizationWill the issuer approve this amount and transaction now?

TokenizationCan a constrained substitute represent the underlying account data?

These controls overlap but are not interchangeable. EMV chip can provide transaction-specific data used in an in-person payment, while EMV 3-D Secure supports data exchange and authentication for card-not-present commerce.^[4]^[5] EMV payment tokenization can replace the primary account number with a token constrained to a merchant, device, or payment scenario.^[3]

Authorization through posting, stage by stage

Stage 1Credential presentation and authentication
The cardholder inserts, taps, swipes, enters account details, or approves a wallet payment. The merchant environment and other participants can evaluate chip data, device signals, a PIN, a security code, or online authentication data.
Stage 2Authorization request and issuer decision
The request includes the amount, merchant and terminal information, credential data, and other risk context. The issuer checks the account and returns an approval, decline, or request for additional action. An approval can reduce available credit before a final purchase posts.
Stage 3Pending activity or authorization hold
A cardholder interface may show a pending item while the merchant has an approved authorization. "Pending" is an account-display state, not a promise that every authorized transaction will settle or that the amount is final.
Stage 4Capture or completion
The merchant confirms that the sale was completed and submits the final transaction record. Capture can happen with authorization or later. The final amount may legitimately differ when the original amount was an estimate or a tip was added under applicable rules.
Stage 5Clearing
Final transaction records move from the merchant side toward the issuer side for editing, reconciliation, fee calculations, currency handling where relevant, and posting. The OCC describes clearing as delivery of final transaction data from acquirers to issuers.^[2]
Stage 6Settlement and merchant funding
Institutions calculate and discharge net obligations. The acquirer or payment provider then funds the merchant under its agreement, generally after applicable fees, reserves, refunds, or other adjustments. Network settlement and the merchant's deposit are related but need not be simultaneous.
Stage 7Account posting and billing
The issuer posts the final purchase to the cardholder's account. The posting date can differ from the purchase and authorization dates. Once posted, the item can enter the applicable billing cycle and statement balance.
Stage 8Cardholder repayment
The cardholder later pays the issuer under the account agreement. That repayment is separate from the original checkout approval and merchant funding.

The money flow runs in the other direction

The OCC's simplified model sends transaction information from merchant to issuer, while funds generally move back from the issuer side toward the merchant side. Third parties, net settlement, fees, reserves, and timing make the real ledger more complex.^[2]

1 · Issuer sideObligation fundedThe issuer side funds its calculated settlement position.

2 · SettlementNet positions dischargedThe network and settlement institutions apply the applicable process.

3 · Acquirer sideFunds receivedThe acquiring side receives its settlement position.

4 · MerchantNet funding deliveredThe provider credits the merchant under its contract and timetable.

5 · LaterCardholder repays issuerThe account holder pays all or part of the billed balance.

Do not collapse the two flowsThe merchant can be funded before the cardholder pays the issuer. The cardholder can see a pending hold before a final record clears. An issuer approval is a message; settlement is a financial process; posting is an account record.

Four common scenarios that change the simple story

Examples explain why the pending amount, final posted amount, and account timing may differ.
Scenario	What happens in the messages	What the cardholder may see
Restaurant tip	An initial amount can be authorized before the final tip-adjusted amount is captured, subject to the merchant's network and acceptance rules.	A pending amount can differ from the final posted purchase.
Hotel or car rental	The merchant may request an estimated authorization, add an incremental authorization if the estimate rises, and reverse an unused amount. Visa's published guide documents this network-specific model.^[6]	Available credit can be reduced by a hold that is larger than the final charge or remains visible until a reversal or expiration is processed.
Refund	A refund is usually a new credit record routed after the original purchase, not a rewind of the original checkout message. A void or authorization reversal before posting is a different operation.	The purchase can remain posted while a separate credit is pending or later posts.
Decline	The issuer may decline, authentication may require more action, or a merchant-side control may stop the attempt. A decline response means the requested transaction did not receive the needed approval.	Usually no posted purchase; a temporary pending attempt or hold can still take time to disappear, depending on the path.

Network rules and merchant categories affect how estimates, increments, reversals, and timing work. A hotel example should not be generalized into a rule for every merchant or every network.

What appears on the cardholder's account

Account label	What it usually represents	What it does not prove
Pending	An authorization or other not-yet-final activity displayed by the issuer.	That the amount will post unchanged or appear on the next statement.
Posted purchase	A completed transaction record entered on the account.	That a later refund, dispute, or adjustment cannot occur.
Reversal or void	Release or cancellation of an authorization or transaction before ordinary completion, depending on timing and system.	That a separately posted purchase was refunded.
Refund or credit	A separate credit that reduces the account balance after processing.	That the original purchase record will disappear.

Issuer interfaces use different labels and update schedules. For a specific transaction, the issuer and merchant can see operational details that a generic article cannot. If an amount looks wrong, preserve the receipt and contact the merchant or issuer through a verified channel rather than assuming every mismatch is fraud.

For the broader relationship between transactions, billing, repayment, and interest, return to how the whole credit card account works.

Sources and method

The diagrams synthesize official U.S. government and payment-standard descriptions into a reader-facing model. Treasury's Card Acquiring Service is a federal-agency acceptance program, so its published flow is used as a transparent example rather than a claim that every private transaction follows identical infrastructure. EMVCo sources support credential, chip, token, and online-authentication claims; they do not define every network's settlement implementation.

[1]U.S. Department of the Treasury, Bureau of the Fiscal Service, How Card Acquiring Service Works (authorization, clearing, and settlement overview; updated Feb. 25, 2026).
[2]Office of the Comptroller of the Currency, Comptroller's Handbook: Merchant Processing (official discussion and diagrams of authorization, clearing, settlement, and merchant processing).
[3]EMVCo, EMV Payment Tokenisation (payment-token purpose, constraints, and ecosystem use).
[4]EMVCo, What is EMV Chip? (chip transaction data and counterfeit-fraud controls).
[5]EMVCo, EMV 3-D Secure (card-not-present authentication and data exchange).
[6]Visa, Authorization and Reversal Processing Requirements for Merchants (network-specific estimated, incremental, and reversal examples; 2024).

Read the sourcing, update, and correction policy.