I requested to overpay my mortgage recently and specically added that I wanted the overpayment to be used to reduce the capital. I got a letter back stating they would do the overpayment but they did not specify that they would remove the payment from the principle. Can someone give me the exact wording (banking term) for this so I can explain this to them again and also can I insist they send me out a statement to show the effect of the overpayment ?