Before overpaying your mortgage, check that your lender allows you to overpay it penalty-free, and if there are any limits as to how much you can overpay.

If you're on your lender's standard variable rate or you're on a tracker mortgage, there is normally no limit on how much you can overpay your mortgage by. However, fixed-rate mortgages typically have an annual overpayment limit of 10% of your TOTAL outstanding mortgage balance.

As the exact method of how this 10% is calculated varies by lender, 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.

Also ensure that any overpayment you make goes to reduce the debt (so shortening the term) rather than reducing your monthly payments. This calculator assumes you reduce the mortgage debt, which is the main benefit of overpaying.