You pay almost all interest in the first few years otherwise. It's the same as minimum payments on credit cards.You may be able to make mortgage overpayments up to a certain amount each year, without having to pay a fee. This will depend on the type of product you have. Making mortgage overpayments can help you save money in interest and clear your mortgage sooner. But first you should check if there are limits and charges. A great way to work out how much to overpay on your mortgage is to use our mortgage overpayment calculator. If you want to overpay on a repayment mortgage, make sure the money goes towards paying off the overall balance, not just the interest. The Mortgage Overpayments calculator calculates the time and interest saved paying off a loan when making regular monthly overpayments. Use our calculator as a rough guide, and be sure to speak to your lender to work out exactly how much you can overpay by.