AVS, INN, CVC and CVC2 codes of debit card

Debit and credit card verification numbers:

AVS (Address Verification System): It is an internal anti-fraud system used by issuing banks to identify the cardholder's address, country of residence, province and zip code. Each credit card has a holder, a natural or legal person, and an internally registered physical address. When a purchase is made online, the holder must enter the country and the postal code. If the card owner does not enter it correctly, the payment gateway notifies the issuing bank and the transaction will be rejected.

IIN (Issuer Identification number): The first four digits of the card identify the bank that provides the card. The same bank that has offices in two different countries issues the cards with the different INN. This number is unique for each bank issuer.

Brand identifier: In English means international identification number of the brand of the card. It is the number that appears in the fifth position of the card and can be composed of 1 or 2 digits. Visa cards start with number 4 and MasterCard has number 5. American Express cards start with number 3 and Discover with 6.

CVC or CVV: Card Verification Code or Card Verification Value. It is a random number, usually composed of 3 or 4 digits, of anti-fraud security that can be located on the back of the credit card. The CVC number is very important since its introduction in Virtual POSs is obligatory and it is used to confirm the purchase and avoid fraudulent activities. If the cardholder does not enter the CVC code or introduces it incorrectly, the operation will be declined.

In American Express the CVC number position is on the front side of the card and consists of 4 digits.

CVC2: The CVC2 numbers are the same as the CVC. The only difference is that a stronger algorithm is used to make it harder to guess.