the p>16-digit credit card number is an international standard, and the first 6 digits are BIN, which is allocated by the international card organization. The first card number is 4, which is a VISA card, and 5 is a Master. 622126~622925 are UnionPay standard cards. The card number starting with 6 is China UnionPay single currency card (or American discover), the credit card starting with 4 is international VISA credit card (the first credit card organization in the world), the international brand MASTERCARD starting with 5, and the Japanese JCB and AMERICANEXPRESS starting with 3. The 7th-15th bits are allocated by banks according to their own needs according to their regional ownership, and the 16th bit is the parity bit. Other non-16-digit card numbers are formulated and allocated by each bank. There is a 16-digit protrusion on the front of the credit card number, and there is a position under one-third of the card. The year and month are separated by a "/"symbol under the card number, and the cardholder's name is at the bottom.