Card Security Codes (CVV2, CVC, CSC, CCID)

Card security codes are 3- or 4-digit codes found on Visa, Mastercard, American Express, and Discover cards. These codes may be printed or embossed and are commonly referred to as CVV2, CVC, CSC, or CCID. Their primary function is to provide an additional layer of security, helping to prevent unauthorized or fraudulent card transactions. The following is a list of the known response codes for verifications:


M	CVV2/CVC2 match.
N	CVV2/CVC2 no match.
P	Not processed.
S	Merchant has indicated that CVV2/CVC2 is not present on card.
U	Issuer is not certified and/or has not provided Visa encryption keys.