CVV2 (Card Verification Value) is an important security feature for credit card transactions on the Internet and over the phone. It is a 3 or 4 digit value printed nowhere except on the card, and can therefore be used to verify that the buyer has the card in their physical possession, giving some protection against credit card fraud.
The code is be found in different places on the various families of cards, and is referred to by several different names:
- Mastercard, Visa and Discover cards have a 3 digit code, called the "CVC" (card validation code), "CVV" (card verification value) and "Cardmember ID" respectively. It is always the final group of numbers printed on the back signature panel of the card.
- American Express cards have a 4 digit code printed on the front side of the card above the number, referred to as the "CID", or Card Identification Number. It is printed flat, not embossed like the card number.
The value of this system of security may be disputed. Anybody who can look at the card or recive payment orders with this validation code can know its value. For this reason it can not be anymore consider that the only person who know the code is the legittate owner of the card after the card is used the first time (or even before that, if anybody can look at the card). Morover the value is also known by the credit card society.