Mod-11 algorithm

Verification of credit card using mod-11

[hlyeoh]

Can I use mod-11 algorithm to verify credit card number?Is there any link or tutorial that you know? Can anyone share with me?thanx.

[olwen]

Search for Credit Card check digit. Credit cards actually use a mod 10 validation, and there are different numbers of digits depending on the card type. There's quite a few sites that explain it, and it's quite simple arithmetic.

You should even turn up the PHP code already written to do it.

Thirty something years ago the first real program I wrote was to calculate valid check digited numbers (not for credit cards though)

[hlyeoh]

yes, i know the existing of mod-10. However, my lecturer required me to use mod-11 instead. I have checked in a lot of website for information about mod-11, but none is used to verify credit card. So, my question is can mod-11 used to verify credit card? I need to find proof to tell my lecturer that mod-11 is not for credit card verification but it is used in other place. Thanks for the info, i still need to keep searching for mod-11 ....

[robho]

mod-11 is used for isbn (standard book numbers), never credit cards.

A search for isbn mod-11 will find details and isbn mod-11 php will find php code.

[hlyeoh]

Thanks for the info everyone. Does that mean other than using mod-10 to verify credit card, there is no other method to verify?

[PCInk]

That is the only way without contact to the bank. Of course, it only tells you if a card number is a valid card number.

Whether that card number is in existence or has ever been in existence is another story - that is what the merchant account does - contacts the bank (if the mod-10 check is valid) to ensure that the card is in existence, checks CVV and expiry dates, if the card has been stopped and credit limits before returning a result.