A merchant category code — or an MCC — is a four-digit number used by credit card companies to classify businesses for payments, taxation and rewards purposes. MCCs affect the interchange rates and ...

Discover how credit card validation codes work and protect against fraud. Learn about their placement, security role, and examples to secure online transactions.

Credit card security codes are three-digit codes on the back of your card (four-digits on the front if you have an American Express card) used to verify that have the physical card. You typically ...