CARD VERIFICATION METHODS (CVM):

Card Verification Methods (VISA = CVV2, MasterCard = CVC2, and American Express = CID use a security code of 3 or 4 extra digits imprinted on the card, but not embedded or encrypted in the magnetic stripe. This verification code does not appear on credit card receipts. Since most fraudulent transactions result from stolen card numbers rather than the actual theft of the card, a customer that supplies this number is much more likely to be in possession of the credit card. VISA claims that the use of AVS with CVV2 validation for card-not-present transactions can reduce chargebacks by as much as 26%.