A very good article about the credit card number format can be found here: Anatomy of Credit Card Numbers As you can see below I get a lot of feedback about this page.Thanks to everyone who stops by to write a note, it is appreciated.
Credit card numbers that conform to the Luhn formula (MOD 10 check).
Usefull for testing e-commerce sites (because they should get past any pre-validation you do, and be declined at the card processor or bank stage).
Test sites cost too, but they’re usually MUCH cheaper – since they don’t really have to bother banks and such – so you might get by with one or two cents a transaction – or a half-cent per – depending on the site. Depending on the site, it will either accept a limited range of valid card numbers, or (as the one I use does) any facially valid card is accepted. If you’re using a test site, it doesn’t give a damn.
Cards that are not facially valid send back a standard CARD_DENY [reason code] message so you can test negative-path too. Put in any CCC you wish, and give the purchaser any name you want.
Once you have narrowed down your list of Internet Service Providers, based on the connections and plans each offers, it is a good idea to check that their naked broadband service is available in your area.