The Meaning of Credit Card Numbers
If you take a close look at your credit
cards, you'll probably wonder what all those numbers
stand for. Every digit actually stands for something
specific. Let's have a look at each of those numbers
in sequence.
The First Digit
Gasoline cards, department store cards
and phone cards have their own programs.
The major credit card companies operate
on a standardized system for assigning credit card
numbers. The first digit in the series will always
be a 3, 4, 5 or 6. This number designates the type
of card you have. For instance, a 3 means it's a travel
and entertainment card, such as American Express or
Diners Club. A 4 is Visa and Visa-branded debit cards,
cash cards; a 5 is MasterCard and MasterCard-branded
debit cards, cash cards; and 6 is Discover.
The Other Numbers
American Express and Diners Club use
the second digit to identify the company. That means
that Diners Club cards will start with either 36 or
38, and American Express cards will lead off with
34 or 37.
The remaining numbers in the series
are used for other purposes, depending upon the card
type and issuer. Generally, the numbers grouped after
the opening series is the routing number of the bank
and the next group is the user's account number. The
final digit is special -- a check digit. This is a
number calculated by applying a specific formula,
and it is used as a fraud check.
Look At Your Card
American Express uses digits 3 and 4
for business or personal card type and the currency
of the cardholder's country of origin. Digits 5 through
11 are the account number. Digits 12 through 14 show
the card number attached to that account. The last
digit is, of course, the check digit.
Visa uses digits 2 through 6 for the
bank number. Beginning with digit 7 and running through
12 or 15, they're the account number, and the last
number is the check digit. The number of digits in
a group may vary because Visa cards don't all have
the same number of digits.
With MasterCard, the second digit through
digit 3 (to as high as 6) is the bank number. All
remaining digits, except the end check digit, identifies
the cardholder's account.
And that's it. A slightly complex system
necessary to track billions of credit cards across
the globe.
Ron King is a full-time researcher,
writer, and web developer. Visit new-credit-card-now to learn more about this fascinating
subject.
Copyright 2005 Ron King. This article
may be reprinted if the resource box is left intact.
