-JCB's credit card numbers are all 16 digits. Generally, the approximate card grade can be seen from the first six digits, and the last 1 digits are randomly generated, which has nothing to do with the opening bank.

Generally, UnionPay single-currency cards start with "62"

UnionPay -VISA dual-currency cards and VISA single-label cards start with 4

UnionPay-MasterCard dual-currency cards start with 5

UnionPay.