1, CVV2 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 CVV and MC 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 custom data area of card magnetic stripe. CVV and CVC are generated in the same way, but they are called in different ways.

2. The validity period of the credit card is lower than the card number. If it is 05/ 18, it means the validity period is 2065438+May 2008, and the input format is 05 18.

Credit cards are generally valid for 3 years, and individual banks have 5 or 8 years. After the expiration of the validity period, the bank will decide whether to let customers continue to use credit cards according to their past use of credit cards.