Is a BIN the same as an IIN?
Yes. BIN and IIN (Issuer Identification Number) name the same prefix of a card number. IIN is the official term in the ISO/IEC 7812-1 standard, while BIN is the older industry name from the time when only banks issued cards. Both identify the card issuer.
In detail
Yes. BIN (Bank Identification Number) and IIN (Issuer Identification Number) describe the same leading digits of a card number. Both identify the institution that issued the card.
Why two names?
IIN is the term used by the international standard ISO/IEC 7812-1, which defines how card numbers are built. BIN is the older industry name, from the time when only banks issued cards. Today, issuers also include fintechs and other licensed institutions, which is why the standard speaks of issuers rather than banks.
In daily operations, PSPs, acquirers and schemes still say “BIN”, as in BIN table, BIN lookup or BIN routing. In contracts and technical specifications, you will often find “IIN”. The 2017 edition of the standard set the IIN at eight digits, so both terms now usually mean an eight-digit prefix.
More context in What Is a BIN? and in the #PayDecoding on network tokens, which use their own token BIN ranges.