There's no universal answer — but there is a simple framework. Set your overpayment somewhere between £50/month (proven habit) and the 10% annual fee-free cap (maximum benefit without ERCs). Where you land depends on your rate, your other goals, and how much cash flexibility you need.
You'll be mortgage-free 6 years 9 months earlier
and save £46,940 in interest.
| Without | With overpay | |
|---|---|---|
| Term | 25 years | 18 years 3 months |
| Total interest | £156,277 | £109,338 |
| You save | £46,940 · 6y 9m |
A lower interest rate could save you thousands more on top. See if you could remortgage to a better deal.
We may receive a commission if you remortgage through a partner broker. This never affects the rate you're offered.
Even £50/month materially shortens a 25-year mortgage. It's a habit, painless, and easy to scale up. This is the right starting point for most UK homeowners.
Above this you trigger an ERC of 1–5% on the excess. On a £200,000 mortgage that's £20,000/year fee-free (~£1,666/month). Going above is rarely worth it unless you're imminently selling, remortgaging or moving to SVR.
10–25% of your fee-free allowance. On £200k, that's £2,000–£5,000/year (£165–£415/month). Big enough to make a serious dent, small enough that you keep a cash buffer for everything else.
Important: This article is for general information and is not financial advice. Always speak to a qualified UK mortgage adviser before making decisions about overpayments, remortgaging, or your specific mortgage product.