An important new security feature for card-not-present transactions now appears on the back of most Visa, MasterCard, and Discover cards, and on the front of American Express cards.
How to find your CVV2 number on Visa, MasterCard & Discover:
Turn your card over and look in the signature strip. You will find either the entire 16-digit string of your card number, or just the last 4 digits, followed by a space, followed by a 3-digit number:
CVV2 Visa & MasterCard CVV2 Discover
That 3-digit number is your CVV2 number. If you cannot read your CVV2 number, you will need to contact the issuing creditor.
On American Express Cards, the CVV2 number is a 4-digit number that appears above and to the right of the imprinted card number, on the front of the card.