If you transfer money from one bank account to another it takes three days whilst the money is in transit, who gets the interest on this money during that period?
You see when you send a payment, your bank will invest the money overnight and the next day once they have made a little money on it they then pass it onto the receiving bank, who also like to invest it overnight and will then pay it to the bank account of who it was intended for. I am guessing that this is the reason for a �25 or sometimes higher charge for a chaps payment as the banks do not get an option to play with your money for a few days.