I tried a test purchase at one of my merchants and got the following:


UK Customers: Do not enter credit card information

Credit Card # 3223322332233223
Valid card number needed to process order

Expiration 08/03 (MM/YY)

FRAUD WARNING: Credit card fraud is a felony and xxxx.com treats fraud attempts seriously. xxxx.com protects consumers by taking numerous steps during and after order submission to detect fraud and provide information for prosecution of fraud attempts.

So far so good. But the same merchant, which approves credit cards within a second, reverses purchases after a month and gives the reason: invalid credit card.

How could this be?