Vv2 is the number printed in the signature area of Visa/Master Card card. It is located in the 3 digits after the credit card number. The last three digits we usually see on the back of a credit card are actually CVV2, not CVV code. CVV2 and CVC2 are also card verification values obtained by the same algorithm, but they are printed on the signature bar when the card is generated. Check CVV/CVC for online transactions (swiping cards) and CVV2/CVC2 for off-site transactions/manual transactions (swiping cards is not allowed). VISA card CVV and MC card CVC are 3-digit or 4-digit numbers generated by card number, expiration date and service constraint code, which are generally written in the 2-track user-defined data area of card magnetic stripe. CVV and CVC are generated in the same way, but they are called in different ways. A verification code (CVN) of a user-defined encryption algorithm is added to the coding rules of bank card number and magnetic stripe data format, and the related bank card is also called CVN bank card. CVV information is stored in the track of magnetic stripe bank card, according to the card number, track master account number, issuer identification code and other information.

This cvv2 can prove that the payer used a credit card when paying, which can avoid the credit card being cheated. Moreover, the ccv2 code of the credit card is equivalent to the credit card password, and the cardholder of the credit card can use this code to swipe the card. In addition, in some foreign websites, you only need to provide the account number and cvv2 code to complete the transaction, and the credit cards of many domestic banks are the same, and you only need to use the security code to complete the payment.

Although this ccv2 code is convenient for payment, it also increases the risk of credit card consumption. Moreover, in recent years, there have been scams that require cardholders to provide cvv2 codes to help increase the limit. This kind of scam will ask the cardholder to provide the card number, expiration date and security code of the credit card in the name of the bank staff, and will deposit it in the expense activation card. If the cardholder doesn't mention the amount at this time, the so-called customer service staff will ask the cardholder to send him the verification code of the withdrawal, so that the credit card will be issued.