According to the ISO standard, the length of bank cards is generally 13- 19 digits, and there are also 12 digits in the world. The length of UnionPay standard cards is generally 16- 19 digits, and dual-organization cards also have 13- 19 digits.

The debit card number of Industrial Bank consists of the following three parts. Top six: Issuer Identification Number (IIN), also known as Bank Identification Number (BIN), applied to ISO by China UnionPay on behalf of domestic issuers, and Industrial Bank generally starts with 622909.

Intermediate digits (7- 18 digits): personal account number (starting from the seventh digit of the card number), with at most 12 digits, and the last digit is the check digit.

Use Luhn algorithm to calculate the number in front of the card number as the last digit of the credit card or debit card.

The steps of checking with Luhn algorithm: starting from the right 1 bit (parity bit), multiply the even number by 2; Add each bit of the product obtained in step 1 to each bit of the original number that is not multiplied by 2; If the total modulus 10 obtained in step 2 is 0, the verification is passed.