What Is a BIN?
A BIN is the first six digits of a payment card. Those six digits encode the issuing bank, the card brand, the card level and the country of issue.
By Daniel Cross, Senior Payment Systems Analyst · Last updated: 2026-10-20
Definition
A BIN (Bank Identification Number) is the first six digits of a payment card. Those six digits encode the issuing bank, the card brand (Visa, Mastercard, AMEX, Discover), the card level and the country of issue. The BIN is also called the IIN (Issuer Identification Number).
- First 6 digits of the PAN
- Identifies issuer bank
- Identifies brand and level
- Identifies country of issue
- Also called IIN
How to read a BIN
Take the first six digits of a card number and run them through a BIN lookup tool. The tool returns the issuer name, brand, card level and country. Only the first six digits are needed - never paste a full card number into a third-party tool.
| Digits | Meaning |
|---|---|
| 1-2 | Brand indicator (4=Visa, 5=Mastercard, 3=AMEX, 6=Discover) |
| 3-6 | Issuer-specific (bank and level) |
| 7-16/19 | Account number (not part of BIN) |
BIN allocation process
Issuers request BIN ranges from the card networks (Visa, Mastercard). The network allocates a 6-digit prefix. The issuer then assigns account numbers within that range. BINs can be reassigned when an issuer portfolio changes.
- Issuer requests BIN range from card network
- Network allocates 6-digit prefix
- Issuer assigns account numbers within range
- BINs reassigned on portfolio changes
- Acquisitions can merge or split BIN ranges
BIN database structure
A BIN database maps the first 6 digits to issuer name, brand, card level, country and sometimes bank contact details. Databases are maintained by third-party providers and updated regularly.
| Field | Source | Update frequency |
|---|---|---|
| Issuer name | Card network registry | Monthly |
| Brand | BIN prefix table | Static per prefix |
| Card level | Issuer portfolio | Quarterly |
| Country | Issuer registration | On change |
How issuers manage BINs
Large issuers hold hundreds of BIN ranges. They segment by product type (credit, debit, prepaid), by region and by card level. BIN management is strategic: new products need new BINs, discontinued products free up ranges.
- Large issuers hold hundreds of BIN ranges
- Segmentation by product type, region and level
- New products require new BIN allocations
- Discontinued products free up ranges
- BIN reuse after a cooling period
BIN changes over time
Issuers reorganise portfolios, so BIN assignments change. Treat BIN results as a strong hint and verify against a current database for production use.
- BIN assignments change when issuers reorganise
- Verify against current database for production
- Treat results as strong hint not guarantee
- Update your BIN database regularly
Frequently Asked Questions
What is a BIN?
The Bank Identification Number - the first six digits of a payment card, identifying issuer, brand, level and country.
What is an IIN?
Issuer Identification Number - the modern name for BIN.
How many digits is a BIN?
Six digits.
Can I look up a full card number?
No - only the first six digits are needed; never paste full card numbers into third-party tools.
Are BIN results always accurate?
No, assignments change; verify against a current database.
Where is the free BIN tool?
On the BIN lookup tool page linked from the navigation.
How often do BINs change?
When issuers reorganise portfolios or are acquired. Update your database regularly.
Can a BIN identify the exact bank?
Yes, the first 6 digits identify the issuing bank and branch in most cases.