Card Scheme
A card scheme is the network that sets the rules for card payments, operates the switch that carries authorisation and clearing messages between issuers and acquirers, licenses the brand, and sets interchange. In the four-party model it neither issues cards nor holds anyone's money.
Also called: card network
Visa and Mastercard are the canonical examples of a four-party scheme: the cardholder’s bank (the issuer) and the merchant’s bank (the acquirer) are both members, the scheme sits between them, and the scheme itself has no relationship with either the cardholder or the merchant. It publishes the operating rules, defines the message formats, runs the network that routes authorisations, calculates clearing and settlement positions, sets interchange rates, and owns the brand that tells a shopkeeper the card will work.
Three-party schemes, of which American Express is the usual example, historically combined issuing and acquiring in one entity, so the scheme was the issuer and the acquirer. That distinction has softened — Amex licenses issuers and acquirers in many markets — but it still explains why pricing and merchant agreements differ in shape between the two models.
Domestic schemes complicate the picture further and are easy to forget from a US or UK desk. Cartes Bancaires in France, Bancontact in Belgium, Elo in Brazil, RuPay in India and UnionPay in China all operate under their own rules, and a card carrying two brands can route down either set of rails depending on the market and the terminal.
In practice
Scheme rules are contract, not law — but for a merchant, a PSP or a programme manager they usually bite harder and faster than regulation does. A scheme can fine, require remediation, or remove a member's ability to transact, and it does not have to go to court first.
Example
A cardholder in Spain buys from a merchant in Poland. The issuer, the acquirer and the merchant are three different companies in two countries; the only thing that makes the transaction possible is that all of them have agreed to the same scheme's rules and message formats.
Commonly confused with
| Term | How it differs |
|---|---|
| Payment Processor | A processor performs the technical work of sending and handling transactions for an issuer or acquirer. The scheme owns the network and the rulebook they all operate under. |
| Payment Gateway | A gateway connects a merchant's checkout to its acquirer. It sits at the edge of the system; the scheme sits at the centre. |
| Payment Rail | A card scheme is one kind of payment rail. ACH, Faster Payments and SWIFT are others, with entirely different rules and economics. |
See also
- IssuerThe issuer is the bank or licensed institution that gives a cardholder their card, holds the account the card draws on, decides whether each transaction is approved, and pays the acquirer for the ones it authorizes. It sits on the cardholder’s side of every card payment.
- AcquirerAn acquirer is the institution that contracts with a merchant to accept card payments, submits those transactions into the card schemes, settles the merchant’s proceeds, and carries the acquiring-side financial exposure — including the cost of chargebacks the merchant cannot fund itself.
- InterchangeInterchange is the fee the acquirer pays the issuer on a card transaction. The card scheme sets the rate, and for most merchants it is the largest single component of the cost of accepting cards — but it is not the whole of that cost.
- Payment ProcessorA payment processor carries out the technical steps of a transaction — authorization, capture, clearing and settlement instructions — for a merchant, an acquirer or an issuer. It generally handles the transaction rather than taking ownership of the money.
- Merchant Category CodeA merchant category code is a four-digit number describing the line of business a merchant is in. It is assigned by the acquirer, standardised internationally as ISO 18245, and it drives interchange, risk treatment, and in some cases whether a card will be authorised at all.
- BIN SponsorshipBIN sponsorship is the arrangement in which a licensed member of a card scheme lets another company run a card programme under the sponsor's scheme membership and BIN range. The programme belongs commercially to the sponsored firm; the scheme relationship and the regulatory responsibility stay with the sponsor.