Summary This article explains how mortgage overpayments work during fixed-rate periods in the UK, including early repayment charges, lender rules, and common limitations. It is for general information only. When you overpay your mortgage, it’s natural to expect your monthly payments to fall. But in the UK, that isn’t always what happens. In reality, mortgage overpayments can reduce: Your mortgage term Your monthly payments Or sometimes both — depending on your lender and how