How to Identify a Credit Card by the Account Number?

When accepting credit card numbers over the phone from customers, you can easily identify the type of card without asking the customer. While each credit card has a unique string of numbers, in varying lengths, the first one or two digits will reveal the issuer of the card. You can also note other characteristics of the number to help you confirm the evidence. The fastest and easy way is to use a credit card generator to generate the details regarding your card.

Identifying by the First Digit

Simply noting the first digit of the credit card account number can help you narrow down or identify the issuer. Credit cards, such as MasterCard, Visa, and Discover, all have unique, identifying numbers as their first digits, with the exception of American Express, Diner's Club, and Carte Blanche, which share the same first digit: the number 3. MasterCard's unique first digit is 5, while Visa's is always 4. A Discover card's first digit is consistently the number 6.

Identifying by Two or More Digits

You can further identify credit cards that start with the same first number by analyzing two or more digits. For example, even though American Express, Diner's Club, and Carte Blanche all start with the number 3, you can confirm American Express numbers if the first digit, 3, is followed by a 4 or a 7. However, if a zero, 6, or 8 follow the 3, the credit card number belongs to a Diner's Club or Carte Blanche account.

Valid Lengths of Account Numbers

Some of the more common issuers of cards have between 13 and 16 digits. Each type of account number has specific lengths, which can serve as a secondary method to identify the type of credit card. For example, Visa account numbers can be up to 19 digits.

If you see a credit card number that starts with a 4 and contains 19 digits, you can assume it's a Visa. Mastercard and Discover account numbers contain 16 digits. American Express contains 15 digits, and Diner's Club and Carte Blanche contain 14 digits.

Categories of Issuing Entities

The first digit of every credit card serves as a major industry identifier or MII. For example, if the first digit of a card number is a 7, the card is issued by an entity related to the petroleum industry, such as a gasoline brand.

Digits 4 and 5 – Visa and MasterCard – relate to the banking and financial industry. The number 6 – Discover – represents merchandising and banking.

Account numbers beginning with 3 – American Express, Diner's Club, and Carte Blanche – tie their issuing entity to the travel and entertainment category. The numbers 1 and 2 relate to airlines or other industry assignments, while the number 8 identifies telecommunications or other industry assignments. A number 9 represents a national assignment entity.

IIN Range Table

The first six or eight digits of a card number (including the initial MII digit) are known as the issuer identification number (IIN). These identify the card-issuing institution that issued the card to the cardholder.

The rest of the number is allocated by the card issuer. The card number's length is its number of digits. Many card issuers print the entire IIN and account number on their card.

In the United States, IIN is also used in NCPDP pharmacy claims to identify processors and are printed on all pharmacy insurance cards. IINs are the primary routing mechanism for real-time claims.

The ISO Register of Issuer Identification Numbers database is managed by the American Bankers Association. ABA is the Registration Authority for this standard and is responsible for allocating IINs to issuers.

Online merchants may use a BIN lookup to help validate transactions. For example, if a card's IIN indicates a bank in one country, while the customer's billing address is in another, the transaction may call for extra scrutiny.