What Do Credit Card Numbers Mean
What Credit Card Numbers Mean

Have you ever looked at one of your credit cards and
wondered what all those numbers mean?

No? Okay maybe I'm just weird. But I'm going to explain
the meaning of credit card numbers to you anyway.

According to industry standards the maximum number of
digits a credit card may have is 19.

The first number indicates the industry of the card issuer.
Airline-issued cards begin with either 1 or 2. Travel and
Entertainment issuers like American Express and Diner's
Club begin with a 3. Banks start with either a 4, 5, or 6.
And gas station cards begin with a 7.

The remaining numbers are used slightly differently by each
credit card company, but the last number is always the check
digit. The check digit is the result of a complex mathematical
formula called the Luhn algorithm.

The Luhn algorithm, also known as "mod 10", was developed in the
1960's by IBM scientist Hans Peter Luhn. It is used to quickly
determine whether or not a credit card number is valid.

Now let's take a closer look at the big three credit card issuers:

American Express

American Express credit card numbers always start with either
a 34 or a 37. The third digit identifies the card as either a
personal card or a business card. The fourth refers to the
currency used in the cardholder's country. The fifth through
eleventh numbers identify the individual cardholder's account,
while the twelfth through fourteenth digits indicate the card
number within the account. Last is the check digit.


With Mastercard, the first digit is always a 5. Digits two through
six refer to the bank holding the account. The remaining digits,
excluding the check digit at the end, make up the cardholder's
account number.


Visa credit card numbers always begin with a 4. Digits two through
six represent the bank number, and the rest of the numbers, excluding
the check digit at the end, make up the cardholder's account number.
Not all Visa cards have the same number of digits, but the majority
of them are sixteen digits long.

Now that you know what credit card numbers mean, you may never look
at them in the same way.

Ed Lathrop is a successful real estate investor and a series 3 commodities futures broker.
He has extensive knowledge of the credit/mortgage markets.  He has built the financial
calculator Website, ezcalculator which is free to use and includes the calculator, "Pay Your
Credit Card Debt Quick."  Ezcalculator can be found at Mortgage Calculator or by going to