We have it constantly with non-EU nationals looking for letters of invitation to attend events in Ireland for visa purposes - bane of my life! Many of the transactions are caught at authorisation point, but at least one or two get through every week. It's a little easier for us - we can see that a gentleman whose email address is george@yahoo.com but who claims to be representing the Ghana Standards Board (just one recent example) is unlikely to be genuine.

Our system notifies us with name and email address of every transaction. Any yahoo/gmail/hotmail addresses are checked before the end of the trading day. If the name on the card does not match the name on the email, or if we have any reason to suspect that the transaction is not genuine, we void the transaction and contact the email address. Most times the phrase "The authorities have rejected your transaction. Please send verification that you are the cardholder" produces silence.

In one case, a client of ours offered a refund on an event that was cancelled. She unwittingly offered it to a fraudulent transaction that she didn't catch (our system connects into their realex a/c directly, so we don't check the transactions). The gentleman sent over his bank a/c details so that the payment could be refunded into that instead of the card... hmmm... me smells interpol...

If you're using Realex, be ruthless in checking and voiding transactions that you have any doubt over - you can always contact the genuine ones later and pick them up.

Good luck soldier! Sarah