Mortgage Overpayment Calculator UK
See the years and interest a regular overpayment could save you.
Mortgage Overpayment Calculator
See how monthly overpayments could shorten your term and reduce interest.
Years saved
— years
Interest saved
£—
New payoff
— mo
Most lenders allow ~10%/year overpayment without ERC. Check your mortgage terms before overpaying large amounts.
Talk to a Mortgage AdviserHow overpayments work
An overpayment pays down extra principal, so all subsequent months charge interest on a smaller balance. The compounding effect means even a modest monthly overpayment can shave years off the term.
Before you overpay
- Check your lender’s annual overpayment allowance during the fixed period.
- Keep an emergency buffer in instant-access savings.
- Compare with high-rate savings / employer pension matching.
- Ask the lender to apply overpayments to “reduce term” for maximum saving.
Frequently asked questions
How much can I overpay without a charge? +
Most UK lenders allow up to 10% of the outstanding balance per calendar year without triggering an Early Repayment Charge during a fixed deal. Always check your mortgage offer.
Is overpaying always worth it? +
It often saves significant interest and can shorten the term substantially. But you should keep an emergency cash buffer and consider whether savings or pension contributions might be better depending on rates.
Reduce term or reduce monthly payment? +
Most lenders default to keeping the term the same and shrinking the next monthly payment slightly. To reduce term, ask the lender to apply overpayments to “reduce term” rather than “reduce balance”.
What about when my fixed deal ends? +
Outside the fixed period most lenders allow unlimited overpayment with no ERC. Many borrowers ramp up overpayments at that point.