[gregjor]

Card companies can usually trace when and where a card number got used. Using fake numbers would not make that any easier.

Likewise card companies can and do report fraud to the relevant law enforcement authorities.

Credit card fraud detection already includes a lot of sophistication. The problem with stopping it and prosecuting offenders comes mainly from the scale of fraud, the relatively low amounts involved, and the cross-border nature of the crime.

Many credit card providers, at least in the US, let their customers generate single-purpose or short-term card numbers, for when you don’t trust the merchant, or need to let someone else use your card.

If we knew in advance that someone intended to scam us we wouldn’t give them a credit card number at all. How would anyone know when to use a fake number?

[kapad]

> Many credit card providers, at least in the US, let their customers generate single-purpose or short-term card numbers, for when you don’t trust the merchant, or need to let someone else use your card.

My experience with using short-term card numbers has been validation failure in the webforms where I try to use them.

[gregjor]

I use them all the time, never had one refused. The web site front end validation can only check the number with the Luhn algorithm — number looks valid. Actual validation and accept/decline gets done by the payment processor.