Life of a Card Payment
You tapped your card and walked off with coffee in four seconds. The money? It needs two more days, five companies, and three fee deductions to arrive.
The walkthrough
The four-second tap hides a two-stage process: authorisation (an instant "is this card good for £3.20?" round-trip) and clearing & settlement (the actual movement of money, which happens in batches over the next 1–3 days).
Authorisation, the fast part. The terminal sends the card details to the acquirer (the merchant's payment bank). The acquirer routes the request over the card network (Visa/Mastercard) to the issuer (your bank). The issuer checks the balance, runs fraud rules, and replies *approve* or *decline*. That message travels back the same chain, typically in under two seconds. No money has moved yet; the issuer has only placed a *hold* on your available balance.
Clearing & settlement, the slow part. At the end of the day the merchant *batches* its approved transactions and sends them to the acquirer. The network nets everyone's obligations and instructs the banks to settle, usually via the central bank's books. Your issuer pays the network, the network pays the acquirer, the acquirer pays the merchant. This is why a "pending" charge can change or drop off: clearing is when it becomes real.
Who takes a cut. On a £3.20 sale the merchant might net ~£3.10. The difference is split between three fees: the interchange fee (set by the network, paid to your issuer, the biggest slice), the scheme/network fee (paid to Visa/Mastercard), and the acquirer markup. Bundled together for small merchants, this is the "merchant discount rate".
The genius and the cost of the system are the same thing: the merchant gets a *guarantee of payment* in seconds, but the actual cash takes days and several intermediaries, each of whom is paid for carrying risk and moving the message.
The rail map
The card payment rail
- 1Cardholder
Taps card at the terminal, sends card data, not money.
- 2Merchant
Terminal forwards the request; will get a payment guarantee in seconds.
- 3Acquirer
The merchant's bank; routes the auth request and later collects settlement.
- 4Card networkwhere value leaks
Visa/Mastercard switch the message and set interchange; net everyone at settlement.
- 5Issuerhighest cost / risk
Your bank: approves/declines, holds the balance, pays at settlement, keeps interchange.
Glossary
Authorisation
The instant approve/decline check that places a hold on funds. No money moves yet.
Clearing & settlement
The batched, end-of-day netting and actual transfer of money between banks (1–3 days).
Acquirer
The merchant's payment bank that connects the till to the card networks.
Issuer
The bank that issued your card and decides whether to approve each payment.
Interchange fee
A fee set by the card network and paid to the issuer, usually the largest part of card costs.
Check yourself
1.When the terminal shows "Approved" two seconds after you tap, what has actually happened to the money?
2.Which fee is typically the largest slice of card-acceptance cost, and who receives it?
3.Why can a "pending" card charge later change amount or disappear?
4.Put the authorisation message path in order from the tap.