Mortgages2 min read · Updated 19 October 2026
Mortgage overpayments: how much you can overpay and what it saves
How overpaying your mortgage works, the usual 10% yearly limit, and a worked example of the interest and years you save.
How an overpayment works
Every pound you overpay reduces the balance, so less interest is charged each month after. If you keep paying your normal amount, the mortgage ends sooner.
The usual limit
Most fixed and discount deals allow about 10% of the balance each year without an early repayment charge. Go above it and you may pay a percentage of the extra. Tracker and standard variable deals often have no limit. Your mortgage offer has the details.
A worked example
£200,000 at 4.5% for 25 years is £1,112 a month.
| Interest with no overpayment | £133,499 |
| Interest paying £200 extra a month | £97,219 |
| Interest saved | £36,280 |
| Time saved | 6 years 1 months |
Overpay or save?
If your savings pay more interest than your mortgage costs, saving can win. If your mortgage rate is higher, overpaying wins. Keep three to six months of costs in easy-access savings first.
Common questions
How much can I overpay on my mortgage?
Often 10% of the balance a year on a fixed deal without a charge. Check your offer.
Should I overpay or save?
Compare the mortgage rate with the savings rate after tax, and keep emergency savings first.
Does overpaying lower my monthly payment?
Only if you ask your lender to recalculate. Otherwise it shortens the term.