Mastercard, Visa, American Express and Discover are all card networks to authorize ... on the front or back. This number can be called the CVV, CVC, CVC2, CSC or CID number. American Express ...

Here is a snapshot: Visa Three numbers Back of the card CVV2 Mastercard Three numbers Back of the card CVC and CVC2 American Express Four numbers Front of the card CID number and CSC Discover ...