Being in the points and miles game means you likely have multiple credit cards. While it’s common knowledge that AMEX cards start with 37x, Visa with a 4x, and MasterCard with a 5x, did you ever wonder about the rest of those numbers? Clearpoint adds a bit of clarity:
A system known as ANSI Standard X4.13-1983 is used by most major credit cards. Each credit card number tells a story about the card: who issued it, the type of account, etc. Compared to the magnetic strip on the back of a card, this isn’t much information, but it’s still useful. Here’s how to decode credit card numbers:
Let’s say your credit card number is 4385822056110982.
The first digit, in this case a “4,” signifies the system being used.
3 – travel/entertainment cards. In this case, different issuers can be identified by the second number on the credit card. For example: American Express (37), Diners Club (38), and Carte Blanche (38).
4 – Visa
5 – MasterCard
6 – Discover Card
Based on this information, you now know that our sample credit card is a Visa. What about the rest of the credit card digits? What can we learn from them? That information, referred to as the structure, is determined by the system being used.
American Express – Digits three and four are type and currency, digits five through 11 represent the account number, digits 12 through 14 make up the card number within the account, and digit 15 is a check digit. A check digit is essentially used for verification and is yielded from and paired with the algorithm that produces the other card numbers.
Visa – Digits two through six make up the bank number, digits seven through 12 or seven through 15 (in some cases) represent the account number, and digit 13 or 16 is a check digit.
MasterCard – Digits two and three, two through four, two through five, or two through six make up the bank number (depending on whether digit two is a 1, 2, 3 or other). The digits after the bank number, up through digit 15, represent the account number, and digit 16 is a check digit.
In our example card, the bank number is “38582,” the account number is “205611,” and the digits “0982” are considered the “check digits.”