How a merchant category code is assigned
The acquirer, or a payment facilitator acting under it, chooses the code at onboarding from the scheme's list. The Visa Core Rules of 18 April 2026 require an acquirer to assign the MCC that most accurately describes the merchant outlet's business, and two or more where separate lines of business share one outlet under set conditions (1.5.1.11).
The Mastercard Rules of 2 June 2026 require the code that reflects the merchant's primary business in authorisation and clearing messages, and call it the acceptor business code (5.8.1). Certain sales carry a set code whatever the merchant's main trade: Mastercard lists gambling, funding and quasi-cash transactions.
What a merchant category code is used for
- Pricing: fee categories can depend on the code
- Issuer controls: a card programme can block or limit categories such as gambling
- Risk: acquirers set reserves and monitoring by category
- Rewards and reporting: cashback rules and expense categories read the code
- Crypto: Mastercard's rules identify a cryptocurrency transaction with MCC 6051
Why the right code matters
A wrong code changes how issuers treat a merchant's payments and how fees apply, and assigning the code correctly is the acquirer's duty under both schemes' rules. A platform that onboards merchants maps each business to its code reliably, and a card issuer builds category rules that its customers can understand.
Where a merchant category code shows up in a platform
Modules that do the work
- Merchant onboardingBusiness sign-up, verification and underwriting, from application to first payment.
- Card acquiringCard acceptance on the phone, in store and online, through the acquirer you choose.
- Card issuingVirtual and physical cards, wallets and controls, on the issuer processor you choose.
- Fraud & riskReal-time fraud scoring, limits and case management, with the risk engines you already trust.
Platforms that need it
Where it is written
The laws and standards this page's facts come from.
- Visa Core Rules and Visa Product and Service Rules, 18 April 2026: 1.5.1.11 and the glossary (Visa)
- Mastercard Rules, 2 June 2026: Rule 5.8.1 and the definition of a cryptocurrency transaction (Mastercard)
General information, not legal advice: what applies to you depends on your services and your market.