The UnionPay card number consists of three parts: the card issuer identification code (BIN), the card issuer’s custom digit, and the verification code. The first six digits are the card BIN; the seventh digit of the card number starting from the card issuer's custom digits, consisting of 6 to 12 digits, assigned by the card issuer; the last digit of the card number is the verification code.

The first 6 digits of the card number identify the issuing bank