Card scheme
The network a card belongs to and the rulebook both the issuer and the acquirer operate under: Visa, Mastercard, American Express, UnionPay, Diners Club and Discover are the six a Singapore merchant meets. Accepting "cards" is really accepting some subset of those six, and which subset is a commercial decision, not a technical one.
Why it matters to a merchant
Schemes set the rules a merchant lives under without ever being a party to their contract: what a chargeback reason code means, how long a dispute window runs, what a terminal must be certified to do. A merchant who wants to know why an acquirer cannot simply waive a rule is usually looking at a scheme rule, and the honest answer from any acquirer is that it is not theirs to waive.
Where this comes up
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Related terms
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