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The first 6–8 digits of a credit card number represent the issuer (IIN, see [0]). Merchants can perform a lookup of those first few digits to their own denylist
by spdustin 4y ago
The first 6–8 digits of a credit card number represent the issuer (IIN, see [0]). Merchants can perform a lookup of those first few digits to their own denylist. Citi’s IIN for temporary cards should (in theory) be the same IIN used to issue non-temporary ones.
[0]: https://en.wikipedia.org/wiki/ISO/IEC_7812 https://en.wikipedia.org/wiki/ISO/IEC_7812