I have a website that processes a fairly small number of monthly credit card transactions, 1-4 per day. However, it didn't take long for the website to be used as a place for requests, mostly from Vietnam, to check the validity of CC numbers. It cost me a lot of money in chargeback fees.<p>I ended up implementing a system using Braintree to do
1) Request an AUTHORIZATION for the amount
2) If the AUTHORIZATION fails, return the error (sounds like I need to change this part, but how to do it without hurting legitimate users?)
3) Send information, including IP and email address, to minFraud
4) If the minFraud riskScore is >= 20, request a VOID on the authorization request
4b) If the riskScore is low, submit a REQUEST SETTLEMENT on the AUTHORIZATION<p>This has worked extremely well, but a few still slip through the minFraud check.<p>Even though Braintree offers it's own fraud checking, I still feel more comfortable with minFraud. I really wish that processors like Braintree would put more effort into fraud detection.<p>I NEVER have this issue with PayPal transactions. Even if it's fraud, they just reverse the transaction and there's no chargeback fee.