In reply to MG:
The rest of us know this already. As with all online banking you need to check and then double check you've got the details right. Also there's normally a big notice exhorting you to check your details as they can't get the money back once it's gone.
I often do a £10 payment to check it's the right account first before going off and sending a large amount.
However I will admit that I did implement a faster payments system at a building society a few years ago.