What is CVV, Card Verification Code?
CVV is a card verification system that verifies that a cardholder is in possession of a credit card by verifying a set of numbers that is embossed on the credit card and not encoded in the magnetic strip. This way even if the card number is stolen, a transaction cannot be processed if the purchaser cannot verify the CVV number on the card.
Requiring CVV in addition to AVS can help to eliminate most fraudulent orders for internet and keyed entry businesses.
Each card issuer has a different name for the CVV system, but all are essentially the same thing. Visa refers to it as CVV2, Mastercard is called CVC2, Amex is CID.
The CVV number is located on the back of the card except for most Amex cards where it is on the front. Amex also uses a 4 digit verification code whereas all other card makers use a 3 digit number.