What Is CVV2 / CVC2 / CID
(Card Verification Value 2, for Visa), CVC2
(Card Validation Code 2, for MasterCard), and CID
(Card Identification Number, for American Express) are values that are used as a security feature for verifying your credit card while making "card not present" transactions. These three- or four-digit values are generated randomly when the credit card is issued and printed on the credit card.
Visa and MasterCard
For Visa and MasterCard, it is a three-digit value that is usually printed in reverse italics and featured on the right side of the signature line on the back of the card.
CVV2 code on the back of a Visa credit card
For American Express cards, it is a four-digit card verification value that can be found on the front of the card just above the card number.
CID code on the front of an Amex card