Here’s everything you ever wanted to know about the Bank Identification Number (BIN.)
The International Organization of Standardization (ISO) oversees the standard that defines Issuer Identification Numbers (IIN,) known as BINs. The American Bankers Association (ABA) manages the pool of numbers available to card issuers.
As of April 2022, Visa and Mastercard started issuing BINs with 8-digit numbers. This did not have any effect on the length of the Primary Account Number (PAN.) Previously they were 6, sometimes even 4.
What can BINs tell us about the card that is being accepted for payment?
The first digit is the Major Industry Identifier (MII)
Information about the bank that issued the card, including whether it’s a domestic or foreign transaction
The card brand
Whether it’s a debit, prepaid, or credit card
Level of the card
The BIN information is what is used much of the time to identify fraudulent charges. If the issuing bank is in one country, but the cardholder’s shipping address or geographic location is another, this can be a red flag. If there’s a data breach, the BIN can be used to identify affected data.
The BIN information can also be used to determine whether the type of card presented is acceptable for the use case – for example, if a prepaid card is presented for a recurring subscription.
BIN Attack Fraud: This is when fraudsters use the first known 6-8 numbers of a credit card and then use software to automatically generate the remaining numbers. They test these combinations, usually with several small-amount authorizations to determine if the numbers are active and valid.
You may already be familiar with the term BIN as it used on the acquiring side. A BIN commonly refers to a group of merchants that belong to an ISO with an acquiring bank. The first 6 digits of a merchant number identify the acquiring BIN. Visa is renaming this identifier to “Acquiring Identifier” to minimize confusion with issuing BINs. This number will remain 6 digits.
There are a number of BIN lookup sites, which are helpful when investigating transactions. Check out this BIN lookup tool hosted by Chargebacks911.