The visa card number has 16 digits, the beginning of the visa credit card is 4, and the Visa card consists of 4 groups of 16 digits.

The number 1-6 indicates the issuing bank's BINNO, the number 7- 12 indicates the serial number of the bank card, the number 13 indicates the difference between the main card and the auxiliary card, the number 14 indicates the issuing date of the card statement, and the number 15 indicates the card number and the number/kloc-0.