Mortgage Overpayment
Calculator
See exactly how much interest you save and how many years you cut off your mortgage by making overpayments — instantly.
💰 You could save even more!
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How Does Mortgage Overpayment Work?
What is a mortgage overpayment?
A mortgage overpayment is any payment above your standard monthly mortgage payment. Even small overpayments can save you thousands of pounds in interest and help you become mortgage-free years earlier.
How much can I overpay on my mortgage?
Most UK lenders allow overpayments of up to 10% of your outstanding balance per year without incurring early repayment charges (ERCs). Always check your mortgage terms or speak to your lender before making overpayments.
Is overpaying my mortgage worth it?
In most cases, yes. Overpaying reduces your outstanding balance, which means interest is calculated on a lower amount each month. This compounds over time, resulting in significant savings. Use our mortgage overpayment calculator above to see your exact savings.
Nationwide, NatWest or Halifax mortgage?
We have dedicated calculators for the UK's biggest lenders. Try our Nationwide mortgage overpayment calculator, NatWest overpayment calculator, or Halifax overpayment calculator.
Mortgage Guides
Should I overpay my mortgage in 2026?
A complete guide to whether overpaying makes sense for your situation.
Read Guide →10 ways to pay off your mortgage faster
Practical strategies UK homeowners use to become mortgage-free early.
Read Guide →Early repayment charges explained
What are ERCs, when do they apply, and how to avoid them.
Read Guide →