How a BIN works
A card number, the primary account number (PAN), starts with the BIN, continues with digits the issuer assigns to the account and ends with a check digit. ISO/IEC 7812-1 is the standard that specifies the numbering system, the format of the card number and the issuer identification number (IIN), which is the standard's name for a BIN.
The card schemes pass the numbers on to their members. In the Visa Core Rules of 18 April 2026 a BIN is an identifier assigned by ISO to Visa and licensed by Visa to an issuer, and the Mastercard Rules of 2 June 2026 describe a BIN as a unique number that Mastercard assigns for a member's use.
What payment systems read from a BIN
A lookup table keyed by BIN tells a payment system what kind of card it is facing before any message is sent:
- The issuer and the country of issue
- The scheme and the card brand
- Debit, credit or prepaid
- Consumer or commercial
Why BINs matter to a payments product
A gateway uses the BIN to choose an acquirer, estimate interchange, tell a domestic card from a foreign one and apply fraud rules. A system that reads only six digits cannot tell apart two BINs that differ in the seventh or eighth, so tables built for six digits had to be rebuilt for eight.
On the issuing side, every card programme runs on a BIN that a licensed issuer holds, its own or a sponsor's. Fraudsters use BINs too: in a BIN attack they generate card numbers under a known BIN and test them.
BIN, IIN or PAN?
- IIN
- Issuer identification number, the name ISO/IEC 7812-1 uses. The Mastercard Rules note that a BIN is sometimes referred to as an IIN.
- PAN
- The primary account number: the whole card number, of which the BIN is the beginning.
- Acquiring identifier
- In the Visa Core Rules, a 6-digit identifier that Visa licenses to an acquirer. It identifies the acquirer, not a card.
Where a BIN shows up in a platform
Modules that do the work
- Card issuingVirtual and physical cards, wallets and controls, on the issuer processor you choose.
- Card acquiringCard acceptance on the phone, in store and online, through the acquirer you choose.
- Fraud & riskReal-time fraud scoring, limits and case management, with the risk engines you already trust.
- CheckoutA hosted checkout for cards, wallets, bank payments and crypto, routed to the best provider.
Platforms that need it
Guides that go deeper
Where it is written
The laws and standards this page's facts come from.
- Visa Core Rules and Visa Product and Service Rules, 18 April 2026: glossary, BIN and Acquiring Identifier (Visa)
- Mastercard Rules, 2 June 2026: definitions, BIN (Mastercard)
- ISO/IEC 7812-1:2017, Identification cards, Identification of issuers, Part 1: Numbering system (ISO)
General information, not legal advice: what applies to you depends on your services and your market.