See exactly how much you save by overpaying your UK mortgage.
Monthly payment (without overpayment)£0.00
Monthly payment (with overpayment)£0.00
Total interest without overpayment£0.00
Total interest with overpayment£0.00
Interest saved£0.00
Time saved0 years, 0 months
New payoff date-
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Year-by-Year Comparison
Year
Balance (standard)
Balance (overpaying)
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How Mortgage Overpayments Work
When you overpay your mortgage, the extra money goes directly towards reducing your outstanding balance. Because interest is calculated on the remaining balance, a lower balance means less interest each month, which creates a compounding effect over time.
The maths behind it
Monthly payment = P x [r(1+r)^n] / [(1+r)^n - 1]
Where P is the loan amount, r is the monthly interest rate (annual rate / 12), and n is the total number of monthly payments. When you add an overpayment each month, the extra amount reduces the principal faster, meaning you pay less total interest and finish paying sooner.
The 10% annual overpayment rule
Most UK lenders on fixed-rate deals allow overpayments of up to 10% of the outstanding balance per year without triggering an early repayment charge. For a £200,000 mortgage, that means up to £20,000 in the first year. This limit typically resets on your mortgage anniversary date.
When overpaying makes sense
Overpaying is usually most effective when your mortgage interest rate is higher than the rate you can earn on savings after tax. Even small regular overpayments can save thousands over the life of a mortgage. For example, overpaying £200 per month on a £200,000 mortgage at 4.5% could save you over £30,000 in interest.
Keep an emergency fund first
Before committing to regular overpayments, make sure you have an emergency fund covering three to six months of expenses. Unlike savings accounts, money overpaid on a mortgage is not easily accessible unless your lender offers a borrow-back facility.
Mortgage Overpayment FAQs
How much can I overpay on my mortgage each year in the UK?
Most UK mortgage lenders allow you to overpay up to 10% of your outstanding mortgage balance each year without penalty. This limit typically resets on the anniversary of your mortgage deal. Check your specific mortgage terms, as some lenders offer higher limits or unlimited overpayments on certain products.
Will I be charged for overpaying my mortgage?
If you stay within your lender's annual overpayment allowance (usually 10%), there is no charge. If you exceed the limit during a fixed or discounted rate period, you may face an early repayment charge (ERC), typically between 1% and 5% of the amount overpaid beyond the allowance. Once you move to a standard variable rate (SVR), most lenders allow unlimited overpayments with no penalty.
Is it better to overpay my mortgage or save the money?
It depends on the interest rates. If your mortgage rate is higher than the rate you can earn on savings (after tax), overpaying your mortgage is typically better because the interest saved is tax-free. For example, if your mortgage is at 4.5% and your savings account pays 3%, overpaying gives a better effective return. Always keep an emergency fund before making overpayments.
Does overpaying reduce my monthly payment or my mortgage term?
With most UK lenders, overpayments reduce your outstanding balance, which shortens the overall term of your mortgage while your monthly payment stays the same. Some lenders offer the option to recalculate and reduce your monthly payment instead. Contact your lender to confirm which method they apply, or ask if you can choose.
Can I get my overpayments back if I need the money?
Some lenders offer a "borrow back" facility that lets you withdraw overpayments you have made, but this is not standard across all providers. With most mortgages, once you make an overpayment, that money is applied to your balance and cannot be reclaimed. If flexibility is important to you, consider an offset mortgage, which keeps your savings separate while reducing the interest charged.