"CVV2" is the credit card security code, which is a security code for credit cards when conducting online or telephone transactions. It is usually a 3 or 4-digit number printed on the credit card, and the location of the printing will vary on different types of cards. It is often used to prevent credit card fraud by verifying that the payer owned the credit card at the time of the transaction.

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

Extended information:

Main purpose

The credit card security code is equivalent to the credit card’s ID card. We can use this code to conduct consumer transactions. Shopping on overseas websites does not require a password. As long as the buyer provides an account number and security code, the transaction can be completed. In China, there are also merchants that have signed contracts with banks to complete phone transfers without a credit card password and only with a security code.

So everyone must keep their credit cards safe and keep them out of their sight when making purchases to avoid others remembering your credit card account number and security code.

Baidu Encyclopedia-Credit Card Security Code