How Credit Card Transactions Work

Swipe Your Credit Card for Approval

You present your card for payment by inserting it into an EMV card reader, tapping it on the terminal for a contactless transaction, or swiping the magnetic stripe. The payment terminal communicates with the merchant bank to ask whether you can make the credit card purchase.

Most credit cards now come with microchip technology. These so-called "smart cards," or "EMV cards" (Europay, Mastercard, and Visa) embed a microchip on the front of the card that contains information pertaining to the account associated with the card, similar to what is contained in the magnetic stripe on the back of the card. Rather than swiping your card, it is inserted into the card reader. Introduced in the United States in 2015, smart cards are considered more secure and less vulnerable to fraud.

Credit Card Authorization

The merchant bank contacts the appropriate credit card network (Visa, Mastercard, American Express, or Discover) to get authorization for the credit card purchase. Then, the payment network contacts the credit card issuer to make sure the credit card is valid and there's enough available credit for the transaction.

American Express and Discover are the payment network and the credit card issuer, so they approve credit card transactions themselves. Visa and Mastercard, however, do not issue credit cards and must contact the credit card issuer.

The credit card issuer sends back an authorization response for the transaction. If your credit card is declined, you won't get a reason at the point of sale, just a message telling you that the card was declined. You'll have to contact your card issuer directly to find out why.

The store’s bank sends their communications electronically either through the phone line or through the internet. Before the widespread use of WiFi (Wireless Fidelity), you may have been to a store or restaurant and heard the screeching and static from the credit card terminal using a dial-up connection to communicate with the merchant bank. Now you know what all the noise was about.

Credit Card Approval

The merchant bank sends the approval message for your credit card purchase, the receipt prints, you sign, and you can leave with your purchase. When you use your card’s EMV chip, the merchant is not required to obtain your signature.

When you leave the store with your purchase, your credit card has only been authorized for the payment. The merchant hasn’t actually been paid, and your credit card hasn’t been charged. If you check your credit card online right after you’ve made a purchase, the credit card issuer may show authorized transactions and may have reduced your available credit by the amount of your recent purchase.

Batch Processing

Typically, at the end of the day, the merchant transmits a batched list of all the credit card transactions that have been made that day and sends them to its bank. Some merchants settle transactions individually in real time as they occur rather than batching them for daily processing. The merchant’s bank then sends the transactions to the appropriate payment network for processing.

The Credit Card Issuer Sends Payment

The credit card network lets each credit card issuer know what payments are due. The credit card issuer keeps a fee, the "interchange fee," as part of its agreement with the merchant, for processing costs and risk. Credit card networks charge an assessment fee to use the network.

The Merchant Gets Paid

The credit card network sends payment to the merchant's bank, which collects its own fee before depositing the credit card charges in the merchant's account.

The Credit Card Issuer Bills You

Each month, the credit card issuer sends a bill for the charges you made during the month. Then, you pay some or all the charges. If you choose to pay only a portion of the charges, you'll pay interest on the amount that you don't pay. The credit card issuer uses your balance and interest payments to reimburse merchants as new transactions are made.