My Merchant Account Blog

How Credit Card Numbers Are Determined

Sunday, November 26, 2006

The card number itself comes from ISO 7812/7816 standards. The first digit on the card will tell you what category it is in per the standards. Four and five identifies the card as banking and financial and six identifies the strip as merchandizing and banking. Three is actually travel and entertainment. The number itself has a structure to it - the first six digits being the Bank Identification Number (BIN).

The method for determining a valid credit card number is known as the mod-10 or Luhn's method (named after the inventor Hans Peter Luhn). The United States issued a patent (295004 8) for this method in August 1960.

MasterCard

MasterCard will usually begin with 51-55 with 16 digits. Usually the first six digits is the BIN and the next nine digits are your account number.

Visa

Visa credit card numbers will begin with a four and have 13 or 16 digits. It can be presumed though that most cards issued with the Visa logo will have 16 digits. Usually the first six digits is the BIN and the next nine digits are your account number.

American Express

American Express will usually begin with a 34 or 37 and have 15 digits. You can also check out the American Express Merchant Reference Guide (October 2010).

Diner's Club

Diner's Club will usually begin with 300-305, 36, or 55. Those beginning with a 36 should have 14 digits will those beginning with 55 will have 16 digits. Keep in mind that in the last quarter of 2004, MasterCard and Diner's club formed an alliance. Cards issued in Canada and the USA start with 55 and are treated as MasterCards worldwide. International cards use the 36 prefix and are treated as Mastercards in Canada and the US, but are treated as Diner's Club cards elsewhere.

Discover Card

Discover Card card will usually begin with 6011 and have 16 digits. Check out Standard Security Features Common to Discover Network Issued Credit Cards for more information.

There are a few other organizations like JCB, Maestro, Solo, Switch, Visa Electron that can be found, however a lot of these are debit cards which might require a personal identification number (PIN) to be used with the transaction.

The last digit of the credit card is known as the check digit - this helps the credit card to be verified properly. The digits between the BIN and the last digit are the account number for the individual.