What Is a Bank Identification Number (BIN)?

Bank Identification Numbers Explained

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A bank identification number (BIN) is a six-digit number used to identify payment card issuers.

A bank identification number (BIN) is a six-digit number used to identify payment card issuers. Bank-issued debit cards, credit cards, prepaid debit cards, gift cards, and electronic benefit cards can all have bank identification numbers.

Definition and Examples of Bank Identification Numbers

A bank identification number is a set of digits used to distinguish one payment card from another. Specifically, a BIN is the first six digits printed or embossed on the front of a payment card. Bank identification numbers can also be referred to as issuer identification numbers (INN).

You can find BINs on:

  • Debit cards that are linked to a checking or money market account
  • Credit cards
  • Charge cards
  • Prepaid debit cards
  • Gift cards
  • Electronic benefit cards
  • Health care payment cards (such as a health savings account (HSA) debit card)

This numbering system was developed by the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO). These organizations create business and industry standards in the U.S. and internationally, respectively. Those standards include the issuance of bank identification numbers and issuer identification numbers.

Bank identification numbers serve an important purpose. They're used to connect card-based transactions with card issuers. Issuer identification numbers are unique in that no two card issuers have the same number. This is what makes it easy to tell card issuers apart if you're familiar with how BINs work.

  • Alternate name: Issuer identification number (INN)
  • Acronym: BIN

The sequence of digits in a BIN is important for determining where the card comes from and what type of card it is. If you have a card's BIN, you can use an online lookup tool to determine:

  • Who the card issuer is (i.e. Visa, Mastercard, American Express, Discover)
  • Whether it's a debit or credit card
  • Whether it's a prepaid card
  • Where the card issuer is located
  • The issuer's phone number

Here are some examples of how a BIN works. Say you have a debit card that has this BIN: 413572. If you type that into a BIN lookup tool, you'll learn this card is issued by Bank of America. It's a Visa-branded debit card issued in the U.S.

Now, assume you have a card with this BIN: 37618. If you enter that into the BIN lookup tool, you'll find this card is issued by American Express. Specifically, it's a credit card issued in Japan.


Bank identification numbers ensure the correct account is debited or credited when a card-based transaction occurs, helping to prevent fraud.

How Bank Identification Numbers Work

The bank identification number or issuer identification number system is a global numbering plan used to identify card issuers. When you use your debit or credit card to make a purchase online or in a store, the BIN is used to determine your card issuer. The remaining digits on the card are used to process the transaction.

This all happens through an electronic payment processing system. This system involves the merchant, its payment processor, the issuing bank, and the merchant's bank. The BIN is used as a marker to verify the authenticity of the transaction. In other words, this is how each party ensures that no fraud is taking place.


Incorrectly entering your bank identification number when shopping online can cause the transaction to be declined.

Traditionally, BINs have been the first four to six digits of a payment card number. Beginning in April 2022, this is set to change. Due to an expected shortage in the availability of new INNs, bank identification numbers will begin using eight digits instead. This won't change the way your card works, but it does have implications for payment processors and card issuers.

Card issuers and payment processors will continue to support six-digit BINs, but new cards are expected to use the eight-digit system.

Key Takeaways

  • Bank identification numbers are used to distinguish one card issuer from another.
  • These numbers can also be referred to as issuer identification numbers (INNs).
  • Traditionally, bank identification numbers have been the first six digits on a payment card, but this will shift to eight digits beginning in 2022.
  • Each BIN is unique to its card issuer, and can tell you whether it's a debit or credit card and what country it was issued in.
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The Balance uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American National Standards Institute. "Issuer Identifier Numbers." Accessed July 29, 2021.

  2. Visa. "Preparing for the Eight-Digit BIN." Accessed July 29, 2021.

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