The CVV (Card Verification Value) is an additional value on your credit card used to verify that the person placing an order is actually in physical possession of the card. Where to Find It:
MC/VISA/DISCOVER: 3-digit number printed in the signature space on the back of the card. The CVV2 number is always the last group of numbers in the signature space on the back of the card. It is not part of your regular credit card number.
AMERICAN EXPRESS: 4-digit number on the front of the card. It is printed (flat), not embossed like the card number.