Bank Identification Number
What is a Bank Identification Number?
Bank Identification Number (BIN), also called a BIN number, is the first six or eight digits of a payment card number that identify the financial institution that issued the card. Those digits sit at the front of the primary account number printed or embossed on the card.
Card schemes assign BIN ranges to issuing banks, so the mapping from digits to institution is authoritative rather than inferred. That's why the BIN is read before anything else happens to a transaction: the systems handling it need to know which bank stands behind the card before they can price it, score it or send it anywhere.
Key facts
- Also known as: BIN number, Issuer Identification Number (IIN), the term used in the ISO/IEC 7812 numbering standard
- Length: six digits historically. Visa and Mastercard began assigning eight-digit BINs under ISO/IEC 7812-1 in April 2022, and six-digit BINs already issued stay valid, so both lengths circulate at once
- Position: the leading digits of the primary account number
- Assigned by: , to
- What it resolves: the issuer, the card network, the issuing country, the card type (credit, debit or prepaid) and the card level (standard, business or commercial)
Types
BIN ranges are grouped by the first digit of the card number, the major industry identifier (MII) defined in ISO/IEC 7812-1. The MII tells a payment system which network a card belongs to before the full BIN is checked. For payment cards, five of these ranges account for almost everything a merchant sees:
- 2 – Mastercard's 2-series range (222100–272099), in use since 2017 alongside the original 5-series
- 3 – travel and entertainment cards, including American Express, Diners Club and JCB
- 4 – Visa
- 5 – Mastercard
- 6 – Discover, UnionPay and other banking and merchandising issuers
How it works
A BIN lookup turns the leading digits of a card number into the attributes a payment system acts on:
- Card number captured. The cardholder enters the number at checkout, or a stored token resolves back to it. On a , this happens before any request exists.
- Network identified. The first digit (and, for some brands, the first two to four) maps the card to its network.
- BIN matched. The first six or eight digits are matched against a BIN table – range files card networks distribute to acquirers and processors, or a commercial BIN database built from them.
- Attributes returned. The match returns issuer, issuing country, card type and card level, which feed routing, pricing and fraud rules.
Since eight-digit BINs arrived, two issuers can share the same first six digits. A system that still matches on six digits can return the wrong issuer or country for an eight-digit BIN, which then skews every rule that depends on it. BIN tables also change as ranges are issued, retired or moved between banks, so a lookup is only as accurate as its last update. A BIN lookup doesn't validate the full card number; that's the job of the check on the last digit.
Why it matters
- Routing. The reads the BIN to send the authorization request to the issuer that can approve it. An authorization built on a BIN the acquirer doesn't recognize can't reach that bank and fails before the issuer ever sees it.
- Cost. is priced by card product, card level and region, and the BIN is what resolves all three. The same purchase amount carries a different rate on a commercial card than on a consumer debit card.
- Fraud screening. BIN data gives risk engines a country and an issuer to compare against the rest of the order. A card issued in one country paired with a delivery address and IP in another is a signal systems weight heavily, and it's also how a is detected: a burst of attempts sharing one BIN with sequential account numbers.
- Checkout logic. In , the BIN lets a merchant display the correct card brand, apply a routing rule per issuer, or decline prepaid cards on a subscription product before the shopper reaches the payment step.
How it compares
Three identifiers with similar names point at different things. The BIN identifies a card issuer; the other two identify a bank or an account for transfers rather than card payments.
| Identifier | What it identifies | Used for |
| Bank Identification Number (BIN) | The bank that issued a payment card | Card authorization routing, interchange pricing, fraud screening |
| A specific bank or branch in the network | Addressing international payment messages | |
| One individual bank account | Cross-border and SEPA bank transfers |
