IIN Lookup
Enter 6 to 11 digits of a card number to identify the issuing institution behind its Issuer Identification Number:
Real production data — the same records the API returns on the free tier.
IIN or BIN?
Both terms describe the same digits. IIN — Issuer Identification Number — is the term used by ISO/IEC 7812, the standard that governs card numbering. BIN — Bank Identification Number — is the older industry term that predates the standard.
The standards body moved to "IIN" for a straightforward reason: not every card issuer is a bank. Airlines, petroleum companies, healthcare networks, and retailers all hold ranges, and calling their prefixes "bank identification numbers" was inaccurate. Our own dataset holds private-label, EBT, and fleet ranges that no bank issued.
In practice "BIN" won. It is what payment teams say, what vendor documentation uses, and what people search for. Treat the two as interchangeable — if a specification says IIN and your processor's docs say BIN, they mean the same field.
Anatomy of a Card Number
ISO/IEC 7812 defines the Primary Account Number as three parts, up to 19 digits in total:
| Component | Length | Purpose |
|---|---|---|
| Issuer Identification Number (IIN) | 8 digits | Identifies the issuing institution. Its first digit is the MII. |
| Individual account identifier | Variable | Distinguishes accounts within the issuer. |
| Check digit | 1 digit | Luhn checksum over the preceding digits. Catches transcription errors. |
Total PAN length varies by product. Across our dataset, 95.5% of ranges expect 16-digit card numbers, 2.8% expect 19, and 1.5% expect 15 — the last group being mostly American Express.
Major Industry Identifier
The MII is the first digit of the card number, and therefore the first digit of the IIN. It tells you the category of issuer before you look anything up:
| MII | Industry |
|---|---|
0 | ISO/TC 68 and other industry assignments |
1 | Airlines |
2 | Airlines, financial, and other future industry assignments |
3 | Travel and entertainment — includes American Express, Diners Club, JCB |
4 | Banking and financial — Visa |
5 | Banking and financial — Mastercard |
6 | Merchandising and banking/financial — Discover, UnionPay, Maestro |
7 | Petroleum and other future industry assignments |
8 | Healthcare, telecommunications, and other future industry assignments |
9 | For assignment by national standards bodies |
The MII is a category, not an issuer. It narrows a card to an industry and usually to a scheme, but it cannot tell you the bank, the country, or the funding type — for that you need the full IIN. See BIN range lookup for the specific prefix ranges each network holds.
The 8-Digit Change
ISO/IEC 7812-1 defined the IIN as 6 digits until its 2017 revision extended it to 8. The driver was supply: 6 digits allow a million ranges, and the schemes were exhausting them. Visa and Mastercard set April 2022 as their migration deadline.
This matters for anything that parses card numbers. A system that slices 6 digits and treats the result as an issuer identifier is reading a truncated IIN — and where a 6-digit range has been subdivided among several institutions, the answer it gets back belongs to whoever holds the parent range rather than the actual issuer. Around 6.6% of records in our dataset resolve differently at 8 digits than at 6.
See the 8-digit BIN checker for a worked example and a migration checklist.
IIN Lookup via API
The API accepts 6 to 11 digits on one POST endpoint and resolves to the most
specific record it holds, so submitting a longer prefix is never worse than a shorter one.
Values longer than 11 digits are rejected and redacted rather than logged.
FAQ
- What is an IIN?
- IIN stands for Issuer Identification Number. It is the leading digits of a payment card number that identify the institution that issued the card, defined by ISO/IEC 7812. Since the 2017 revision of that standard, an IIN is 8 digits.
- What is the difference between an IIN and a BIN?
- They refer to the same digits. IIN is the current standards term; BIN — Bank Identification Number — is the older industry term that predates the standard and remains far more common in everyday use. If a document says BIN and another says IIN, they mean the same field.
- Is an IIN 6 or 8 digits?
- Eight. ISO/IEC 7812-1 defined the IIN as 6 digits until its 2017 revision moved it to 8, and Visa and Mastercard completed their migration in April 2022. Plenty of systems still assume 6, which is why lookups on subdivided ranges return the wrong issuer.
- What is the MII?
- The Major Industry Identifier is the first digit of the card number and the first digit of the IIN. It indicates the broad category of issuer — 4 and 5 are banking and financial, 3 is travel and entertainment, 7 is petroleum, and so on.
- How do I look up an IIN?
- Enter 6 to 11 digits of the card number in the tool on this page, or send them to the API. You get the issuing institution, card scheme, funding type, card level, country, and currency back.
- Is the IIN the same as the account number?
- No. Under ISO/IEC 7812 the full card number — the PAN — is the IIN, followed by the individual account identifier, followed by a single check digit. The IIN identifies the issuer; the account identifier distinguishes accounts within that issuer.