Validating Credit Card Numbers in One Step

Stephen P. Morse, San Francisco




Enter Credit Card Number here

Issuer:
Bank:
Validity:

Validity above merely means that the number has the correct structure.
It does not mean that the number has actually been issued or is in good standing.

Here are the rules for determining the issuer based on the leading digits of the number.

1800JCB
2014Diner's Club / enRoute
2131JCB
2149Diner's Club / enRoute
300 to 305Diner's Club / Carte Blanche
34American Express
36Diner's Club / International
37American Express
38Diner's Club / Carte Blanche
3 (all others)JCB
4Visa
51 to 55MasterCard
6011Discover


Algorithm for determine number validity comes from SemaphoreCorp.
Bank identification presented here comes from Wikipedia.

© Stephen P. Morse, 2007