How many digits is the SMS verification code when ABC modifies the card password?

On the back of each credit card, two sets of numbers are usually displayed in italics at the top of the signature. The first four digits are the last four digits of the card number, and the last three digits are commonly called "the last three digits". It is a verification code set by commercial banks to ensure the security of credit card passwords, and it is used for indirect credit card consumption transactions for bank cards.

For example, online payment and other transactions, so the "last three yards" of the credit card cannot be leaked.