What is a merchant category code (MCC)?

A merchant category code is a four-digit number, defined by ISO 18245, that classifies a merchant by its main type of business. It is sent with every card transaction so issuers can apply approval rules, fraud checks, pricing, rewards and spending controls.

Examples of MCCs

• 5411: grocery stores and supermarkets.
• 5812: restaurants.
• 4121: taxis and limousines.
• 7995: betting, including lottery tickets and casino chips.

What the MCC is used for

• Issuers use it in authorization and fraud rules, and some block whole categories.
• Card schemes use it to set certain interchange rates and to apply specific rules, for example for high-risk categories.
• Rewards programs use it to give extra points on travel or dining.
• Corporate card programs use it to restrict what employees can buy.
• Tax and reporting rules in some countries rely on it.

Why accuracy matters

A wrong MCC can lead to unexpected declines, wrong interchange, missed scheme obligations and compliance issues. Card network rules require acquirers to assign the code that matches the merchant's real activity.

What it means for payment operators

If you onboard merchants, assigning the right MCC is part of your onboarding responsibility. Capturing business activity in the onboarding workflow, and using the MCC in routing rules, helps your merchants get correct treatment by issuers and schemes from the first transaction.