Overpaying Your Mortgage by £300 a Month: What Could It Do?
This guide is for general information only and does not provide financial advice. Check your lender’s terms before overpaying, as early repayment charges may apply. Your home may be repossessed if you do not keep up repayments on your mortgage.
Overpaying by £300 a month can reduce the interest you pay and bring your mortgage-free date forward, but the effect depends on your balance, rate and how long you keep it up. This page shows estimates for five balances, then asks a question most examples skip: what if you stop after a few years?
That is £3,600 a year. Whether it fits your budget, and whether it stays within your lender’s yearly allowance (often a percentage of the balance, but lender-specific), are for you to check. See the UK mortgage overpayment cap.
What it could do, by balance
The table shows estimates for five balances at 4.5% with 25 years remaining. It assumes your lender keeps your payment the same, so the mortgage ends sooner, and that no fees or early repayment charges apply.
| Balance | Estimated result | Try it |
|---|---|---|
| £100,000 | about £34,921 of interest saved, 12 years 1 month sooner | Open in calculator |
| £150,000 | about £42,499 of interest saved, 9 years 8 months sooner | Open in calculator |
| £200,000 | about £47,709 of interest saved, 8 years 1 month sooner | Open in calculator |
| £250,000 | about £51,515 of interest saved, 6 years 11 months sooner | Open in calculator |
| £300,000 | about £54,420 of interest saved, 6 years 1 month sooner | Open in calculator |
What if you only keep it up for a while?
Circumstances change, so you may not overpay at the same level for 25 years. For a £200,000 balance at 4.5% with 25 years left, this table shows estimates if you overpay £300 a month for part of the term and then stop.
| Overpaying for | Estimated result |
|---|---|
| 5 years, then stop | about £27,830 saved, 3 years 5 months sooner |
| 10 years, then stop | about £41,955 saved, 5 years 10 months sooner |
| 15 years, then stop | about £47,333 saved, 7 years 7 months sooner |
| the whole term | about £47,709 of interest saved, 8 years 1 month sooner |
The early years do most of the work because money that reaches your mortgage sooner has longer to reduce interest, other things being equal. Overpaying for a few years and then stopping can still make a difference. Whether you can stop or change a regular overpayment, and whether your lender needs notice, depends on your lender, so check how yours handles it.
To see how the interest rate changes figures like these, read how your rate changes what overpaying does.
Figures are estimates from this site’s calculator. They assume a repayment mortgage, a rate that stays the same for the whole term and no fees or early repayment charges, and they are illustrations, not forecasts. Try your own figures in the free mortgage overpayment calculator.
If you are unsure whether overpaying suits you, consider speaking to a regulated mortgage adviser.
Questions people ask
Is £300 a month worth overpaying?
It can reduce the interest you pay and shorten your mortgage, but the effect depends on your balance, rate and term. The tables show estimates, including what happens if you stop after a few years. See should I overpay my mortgage?
Can I stop overpaying if I need to?
It depends on your lender. Overpaying is often optional, but a lender may need notice for a regular overpayment, so check how yours works before you set one up.
Is £300 a month within my allowance?
£300 a month is £3,600 a year, which would be within an example 10% allowance on a balance of £36,000 or more. Allowances vary by lender, so check your mortgage offer.
Other worked examples
overpaying £200 a month, overpaying £500 a month, overpaying £1,000 a month, how your rate changes what overpaying does, how much to overpay to clear your mortgage sooner. For how much to overpay in general, see how much should I overpay?