What is the Bank Identification Number?


Everything Merchants Need to Know about Bank Identification Numbers (BINs) and Issuer Identification Numbers (IINs)

The payment industry is littered with confusing terms and acronyms. For example, what is the BIN? How does it differ from the IIN? How do industry members typically use the bank identification number?

What is a Bank Identification Number?

A Bank Identification Number (commonly abbreviated to BIN) is the first sequence in a credit card number and is used to identify the card’s issuer.

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Another term used commonly to refer to this sequence is the Issuer Identification Number (or IIN). This more generalized term is the result of an increasing number of non-bank institutions, such as American Express, who opt into the BIN network.

Typically between four and six digits, the BIN or IIN listed on each card is specific to the bank which issued that card. BINs help merchants identify the cardholder’s issuing bank.

What Do the Digits Mean?

The digits of a cardholder’s account number can be thought of as a code. While the first six digits make up the BIN/IIN, the first digit on its own possesses a certain significance.

Referred to as the Major Industry Identifier (MII), the first digit of the card number identifies the type of institution which issued the card in question. The meanings signified by the MII are as follows:

MII Digit Value Issuer Category
0 ISO/TC 68 Assignment
1 Airline cards
2 Airlines cards (and other future industry assignments)
3 Travel and Entertainment Cards
4 Banking and Financial Cards
5 Banking and Financial Cards
6 Merchandising and Financial Cards
7 Gas Cards, Other Future Industry Assignments
8 Healthcare Cards, Telecommunications, Other Future Industry Assignments
9 For Use by National Standards Bodies

When looking at the full credit card number, the first digit will identify the card issuer’s industry, while the first six digits collectively will identify the specific institution which issued the card. Some of the most familiar examples include:

  • Visa: 4*****
  • American Express (AMEX): 34**** or 37****
  • Diner’s Club: 36****
  • MasterCard: 51**** or 55****
  • Discover Card: 6011, 622126-622925, 644-649, 65

Visa and MasterCard are classified as financial payment cards, while Diner’s Club and American Express are considered travel and entertainment cards.

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Upcoming Changes to BINs and IINs

The approximately 12 remaining digits on the card are the individual account identifier. Considering the numbering combinations available with those 12 digits, it is possible for each issuer to have about a trillion different account numbers for their cardholders.

While there won’t likely be a shortage of account numbers any time soon, industry insiders are worried about depleting the availability of BINs. In 2015, a discussion began regarding the length of BINs; experts are considering extending the BIN from six digits to eight or introducing an alpha-numeric system.

Want More Information?

The BIN, IIN and MII numbers can help merchants analyze and assess their payment card transactions. If you’d like more information on how to use these digits to your advantage, contact Chargebacks911® today. Our payment experts can help you explore different reporting and revenue optimization techniques.

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