1. The bank card number consists of the following three parts: the issuer's identification code (BIN number), the issuer's custom bit and the check code.
2. The first six digits of the bank card number are the BIN number, which is the abbreviation of the bank identification number, and is assigned by the International Organization for Standardization (ISO) to all bank card organizations engaged in inter-bank transfer exchange.
3. General: 4 prefix-visa; 5 prefix-MasterCard; 62- China UnionPay; 3 prefixes-express, JCB, etc.
4. The user-defined bit length of the issuing bank can be 6- 12, which generally includes the bank's internal branch identification. For example, 6-7 digits, 0 1 stands for Beijing card, and the rest will be generated immediately.
5. The last check code of the last card number has certain calculation rules for anti-counterfeiting. UnionPay standard cards meet the standards of China UnionPay, and use the BIN codes assigned by China UnionPay (currently 622 126-622925, 800 cards in total), which can be used within the payment network and protocol network of China UnionPay.