"CVV2" is the security code of credit card, which is the security code of credit card when conducting online or telephone transactions. Generally, it is a 3-digit or 4-digit number printed on a credit card, and the printing position of different types of cards will be different. It is usually used to prove that the payer has a credit card at the time of transaction, thus preventing credit card fraud.

The credit card security code is a set of 3 or 4 digits on the credit card. Its generation method is that the bank extracts the account number, validity period and service code of the card, arranges them and then calculates them through a series of complicated algorithms. After this set of numbers is generated, only the issuing bank and the holder of the bank card know what this number is.

Extended data:

Main applications

The credit card security code is equivalent to the credit card ID card, and we can use this code for consumer transactions. You don't need a password to shop on overseas websites. As long as the buyer provides the account number and security code, the transaction can be completed. In China, there are also merchants signing contracts with banks, but you don't need a credit card password, you only need a security code to complete the telephone transfer.

Therefore, everyone must take good care of their credit cards, and don't let them leave their sight when spending, so as to avoid others remembering your credit card account number and security code.

Baidu encyclopedia-credit card security code