#mastercard

2

Posts on x2q tagged mastercard. Updated as new posts are published.

Jun 6, 2026
8-digit BINs explained: what the IIN expansion means for card BIN lookups (2026)
The card networks expanded the issuer identifier on a payment card from 6 to 8 digits. For anyone doing BIN/IIN lookups it means a 6-digit prefix is no longer guaranteed to identify a single issuer — you often need 8 digits to disambiguate. Here's the what, the why, and the practical fallout.
Apr 22, 2026
binlist.net — how a Fuerteventura holiday side-project became iinlist.com
In 2013, sitting on a balcony in Playitas, Fuerteventura, I built binlist.net as my first ever Go project — a free HTTP API for looking up the issuer of a credit card from its first six digits. It hit 1 million queries/day by 2015. Thirteen years later it's still free, and its commercial sibling iinlist.com is the one we run the business on.