alt Hacker NewsThe number space between the first 6 digits (BIN) and the Luhn check digit is 9 digits — that's 1 billion numbers that issuers can give out before a collision happens.
The number space between the first 6 digits (BIN) and the Luhn check digit is 9 digits — that's 1 billion numbers that issuers can give out before a collision happens.
That doesn't seem to be more than an order of magnitude off between available numbers and issued cards - a cursory search says there are over a billion credit cards in circulation in the US alone.