Re:Japan facing credit card number shortage
by sgjohnson on Tuesday August 25, 2020 @09:40PM
(#24278183)
No bank does addressing like that.
Amex for example have got only 6 digits per prefix. 15 digit card number, 6 digit BIN, 7 digit account number, 1 digit representing which card it is (1 for the first, and it gets bumped up with any replacements), and 2 digits for the position on account, allowing you to have 99 supplementary cards on account that can then be identified.
Obviously this is just Amex and it's an absolute non issue for them seeing that they own the entire 37 and 34 range, but I can assure you that virtually no financial institution actually use all of the 9 digits like that.
Amex for example have got only 6 digits per prefix. 15 digit card number, 6 digit BIN, 7 digit account number, 1 digit representing which card it is (1 for the first, and it gets bumped up with any replacements), and 2 digits for the position on account, allowing you to have 99 supplementary cards on account that can then be identified.
Obviously this is just Amex and it's an absolute non issue for them seeing that they own the entire 37 and 34 range, but I can assure you that virtually no financial institution actually use all of the 9 digits like that.