How a card payment works – what happens in the two seconds after you tap

Four parties, one tap

A card payment looks like a transaction between you and a shop. In reality at least four parties are involved: you (the cardholder), the shop (the merchant), the shop's bank (the acquirer) and your bank (the issuer). Between the two banks sits the card network – for example Visa or Mastercard – which routes messages and settles the money.

When you tap, the terminal sends the payment request to the acquirer, which forwards it through the network to your issuer. The issuer checks the card, the available balance or credit limit and fraud signals, then answers with an approval or a decline. All of this normally takes one to two seconds.

Authorization is not settlement

The approval you see at the terminal is an authorization: your issuer promises to pay. The actual movement of money – settlement – happens later, usually in a batch at the end of the day or the next business day. That is why a payment can show as "pending" in your banking app before it becomes a final entry.

Where the fees go

The merchant does not receive the full amount. From a purchase of 100 units, roughly 1 to 3 percent is deducted, depending on the country, card type and contract. This merchant service charge is split: the largest part, the interchange fee, goes to the issuer; the card network receives a scheme fee; the acquirer and the payment service provider keep the rest as their margin.

In the European Union interchange for consumer cards is capped by regulation (0.2 % for debit, 0.3 % for credit cards). In the United States and many other markets it is higher, which is one reason merchant fees vary so much between countries.

Why this matters beyond banking

Because fees are generated on every single transaction, payment infrastructure is one of the most stable revenue streams in the economy. Historically, only banks, networks and large processors participated in it. Newer models – including blockchain-based protocols such as SHOP – try to link part of this activity to digital ecosystems. Understanding the classic flow first makes it much easier to judge whether such models are plausible.

The numbers on the Novaro homepage (hundreds of billions of card transactions and a payment volume of tens of trillions of US dollars per year) are industry estimates and vary by source; the order of magnitude, however, is undisputed.

Key terms

Issuer: the bank that gave you the card. Acquirer: the bank or provider that gives the merchant a payment account. Card network (scheme): Visa, Mastercard and others that connect issuers and acquirers. Interchange: the fee the acquirer pays to the issuer for each transaction. Settlement: the actual transfer of money after authorization.