What is the CVV2 or CVC2? The CVV2/CVC2 is a three-digit security code, printed on the back of the cards. The code appears at the end of the card number (see sample). American Express is printing a four-digit security code on the front of the card.
Visa
Card Verification Value (CVV2). 3-digits in reverse italic to the right of the cc number in the signature area on back.
Master Card
Card Verification Value (CVC2). 3-digits in reverse italic to the right of the cc number in the signature area on back.
American Express
Card Identification Number (CID). 4-digits printed (not embossed) on the right front of the card above the cc number.
Discover Card
Card Identification Number (CID). 3-digits in reverse italic to the right of the cc number in the signature area on back.