The type of business I run allows customers to get results before they pay. I take their credit card information when they sign up, and afterwords anywhere from a week to a month charge them for my services. Most of the time this goes smoothly, but occasionally people will try and game the system by using virtual credit cards, and throw away debit cards (like you might buy at Wallmart) to game the system. I've done some research and found http://en.wikipedia.org/wiki/List_of_Bank_Identification_Numbers, but it's not a complete list. Is there anyway to identify where the numbers come from. Or has anyone had any experience with this issue, and might be able to give me some ideas for combating this problem? Thanks