We are always getting cc payments declined and the bank wont tell us why, its mostly when people try and order overseas... a few days ago we had 1,200 declined in one day... (i think 2-3 attempts may be the same person - so it could just be 300-600 persons/orders declined) any ideas why, or how to avoid? Is this normal?
if they are from overseas,then it is highly likely they are fraudulent and your merchant account provider has filetered them out to save you from losing money. With some merchants accounts like worldpay,you can set up your features to block certain transactions
you are a happy camper...2co didn't filter few, and I had to deal with bank charge back, which is pain in the &^^
What you are seeing is called carding or card testing. I wrote an article about it a few years back: http://www.merchantaccountblog.com/36/what-does-a-fraudulent-transaction-look-like What gateway are you using?