Understanding Your Credit Card’s Card Identification Number

There are numbers all over credit cards. Are they random, or is there some sort of underlying order?

The small three-digit “security code” on the back of a credit card is confusing to some. Why, some may ask, is it necessary? There’s already a 13-19 digit number right across the front that should keep the card safe enough.

But there is a reason for the complex system of identification on credit cards. The three-digit security code, which merchants most often ask for when they can’t see you, is to make sure that you have the actual credit card in your possession. This is why it’s extremely important to guard that code. There are numerous online or over-the-phone transactions that can’t be made without that code.

The main number on the front of the card consists of four parts:

1. The major industry identifier – The first digit represents the type of your card. It’s either a 3,4,5, or 6. 3 means it’s a travel or entertainment card like a Diners Club or American Express card. A 4 is a Visa card. A 5 is a MasterCard and a 6 is a Discover Card.  Sometimes the second digit is also an identifier. For example, 36 or 38 is Diners Club, while 34 or 37 is American Express.

2. A six-digit card issuer identifier – Certain financial institutions use this group to classify the type of card. The third and fourth digit on an American Express card is used for personal or business cards, while digits five to 11 are the account number and digits 12 to 14 represent the card number attached to the account. This obviously varies from institution to institution.

3. An account number- This is the only “random” and original number on your card. This is what distinguishes your card from other people’s of the same kind. The number of digits varies.

4. A checksum digit – This is the last digit. The company applies a formula to the preceding digits to make sure the last digit is authentic. This is to prevent fraud artists from figuring out or guessing card numbers. The formula to get to the check digit is kept a secret.

It should be comforting to know that such care is taken in creating your credit card number. It’s all done in the name of safety to protect you from the increasingly capable scam artists.

If you do, however, find it necessary there are a variety of sources for loans from reputable companies.