At MaxMind, we approach fraud screening in a different way. We examine an online transaction from various angles. Our tools are not geared towards verifying the authenticity of the credit card details used for the purchase, but rather, identifying if the purchaser is the legitimate card holder. Through our analysis, we have been able to identify traits and patterns that are associated with fraudulent orders. By asking the right questions, we can provide e-commerce businesses with the necessary information to detect fraudulent orders before the payment is processed.

For a card with an even number of digits, double every odd numbered digit and subtract 9 if the product is greater than 9. Add up all the even digits as well as the doubled-odd digits, and the result must be a multiple of 10 or it's not a valid card. If the card has an odd number of digits, perform the same addition doubling the even numbered digits instead.