The last three digits of a credit card, also known as cvv2 code, are the numbers printed in the signature area on the back of the card. At present, some online payments do not require password payment, especially in the field of telephone payment. Only the cardholder's ID number, credit card number and the last three digits on the back of the card (namely cvv2 code) are needed for successful payment. The reason why a cvv2 code is added to the back of the card is actually to confirm that the card is really in the cardholder's own hand. At this point, the cvv code is equivalent to the "second password" of the credit card.

This number is very important, but it cannot be used alone. If others want to use your credit card, they must know your credit card number, expiration date, cardholder's name and the last three yards. Some people suggested crossing out the last three yards, but bankers said it was easy to scratch the data chip or magnetic stripe of the credit card. The best way is to pay more attention to yourself, don't let the credit card leave your sight when spending, and prevent people with ulterior motives from recording these figures.