Understanding Your Credit Card Number

June 30, 2014, Written By Lynn Oldshue
Credit Cards

Do you know what the numbers mean on the front of your credit card? Are they just a random accumulation of numbers? Or do they serve a specific purpose?

Much like the VIN on your car, credit card numbers are set up to identify certain components of your account. The VIN tells you what manufacturer made your car and even what color it is. The credit card number tells what company issued your credit card but also a great deal about your account information.

The first number of a credit card is called the Major Industry Identifier. It will signify the industry of the issuer. Travel and entertainment cards begin with the number 3, so all American Express (34 and 37) and Diners Club (30) begin with a 3. The number 4 and 5 represent the financial and banking cards–all Visa cards start with a 4, MasterCards with a 5. The number 6 signifies the merchandising and banking cards, and that is why all Discover cards start with a 6. The petroleum industry is represented by 7, so all gasoline credit cards begin with this number. 

Following this Major Industry Identifier number are the specific numbers that represent the bank that issued the card. Then comes the numbers that identify your individual account.

The final digit on any credit card is known as the “check digit,” and it is determined by a complex algorithm created by an IBM scientist, Hans Peter Luhn, in 1954. While every other digit has a special meaning, this check digit is randomly selected and helps deter thieves from inventing credit card numbers, since only one out of every ten will be valid.  

Will knowing any of this change the way you swipe your card? Probably not. Nevertheless, it does give you insight into the complexity of the development of a credit card number.



The information contained within this article was accurate as of June 30, 2014. For up-to-date
information on any of the terms, cards or offers mentioned above, visit the issuer's website.