If you have some spare money each month, or perhaps a lump sum sitting in savings, you might be wondering whether you should use it to reduce your mortgage.

For some people, overpaying their mortgage can make a lot of sense. It can reduce the amount of interest they pay and potentially help them pay off their mortgage sooner.

That doesn’t automatically mean it is the best use of your money.

Before making an overpayment, it is worth looking at your mortgage, your savings and your wider financial plans.

What happens when you overpay your mortgage?

When you make an overpayment, you reduce the outstanding balance of your mortgage more quickly than originally planned.

As mortgage interest is normally calculated on the amount you owe, reducing the balance can mean paying less interest in the future.

Depending on your mortgage and how you make the overpayment, it could also help you repay the mortgage sooner.

The higher your mortgage rate, the greater the potential interest saving from reducing the balance. This is one reason the question may be particularly relevant for people whose current fixed rate is coming to an end.

Could overpaying help when you remortgage?

Potentially.

Reducing your mortgage balance means you will owe less when the time comes to remortgage.

It could also reduce your loan-to-value (LTV), which is the percentage of your property’s value that you need to borrow.

Mortgage products are often priced in different LTV bands. If an overpayment moves you into a lower band, you may potentially have access to different mortgage options.

That doesn’t mean you should automatically use savings to reduce your mortgage before remortgaging. The amount required to reach the next LTV band, the mortgage options available and what else you could do with the money all need to be considered.

When could overpaying your mortgage make sense?

It may be worth considering if you have surplus income or savings, an adequate emergency fund and no more expensive debts that would make sense to repay first.

For some people, reducing their mortgage is also about more than the interest saved.

You may want to pay your mortgage off sooner, reduce your monthly commitments in the future or simply feel more comfortable knowing that you owe less on your home.

Those are perfectly valid considerations too.

When might you think twice?

Money paid into your mortgage will not necessarily be easy to get back.

If using £10,000 to reduce your mortgage leaves you with very little accessible savings, for example, you could find yourself having to borrow money again if an unexpected expense arises.

Other debts also matter. Paying down a mortgage while continuing to pay a much higher rate of interest on a credit card or personal loan may not make financial sense.

There may also be other uses for the money, including savings, pensions or investments. Those decisions involve different risks and potential returns, so the right answer isn’t simply determined by your mortgage rate.

Check how much you’re allowed to overpay

This is important.

Many mortgages allow you to make overpayments, but the amount you can repay without charge varies between lenders and mortgage products.

If you exceed the permitted amount during a period when an early repayment charge applies, you could face a penalty.

Always check the terms of your particular mortgage before making a significant overpayment.

What about making a lump sum before your current mortgage deal ends?

This is something we are asked about regularly, particularly when someone is approaching the end of a fixed rate.

Imagine you have £20,000 available and your mortgage deal is due to end in six months.

You could use the money to reduce the mortgage immediately. Alternatively, you could keep it accessible for the time being and consider using some or all of it when you remortgage.

Which option makes more sense can depend on your current interest rate, any early repayment charges, the return available on your savings, your future mortgage options and how much cash you want to retain.

It is therefore worth looking at the numbers before making the decision rather than assuming that paying the mortgage down immediately must be the best option.

Should you overpay each month or make a lump sum?

Both can reduce your mortgage balance.

A regular monthly overpayment can be a relatively painless way of gradually reducing what you owe, while a lump sum can make a more immediate difference.

The right approach depends on how predictable your income is and how much flexibility you want to retain.

Someone with a regular salary may be comfortable committing to a monthly overpayment. Someone whose income varies, such as a business owner or contractor, may prefer to keep their money accessible and make occasional lump-sum payments instead.

Our Thoughts

Overpaying a mortgage can be a very effective way of reducing debt and potentially saving interest, but we don’t think the starting point should simply be:

“How much can I overpay?”

A better question is:

“What is the best use of this money for me?”

That means looking at your mortgage rate, the remaining term, savings, other debts, emergency funds and future plans.

If your mortgage deal is approaching its end, it can be particularly useful to look at overpayments as part of the wider remortgage conversation.

Reducing the balance could make sense, but retaining the money could give you more flexibility. In some cases, the amount you repay could even affect which loan-to-value band you fall into and the mortgage options available to you.

The important thing is to understand the effect of each option before committing the money.

If you’d like us to look at your existing mortgage and the effect an overpayment could have, please get in touch.

Information correct at time of writing – October 2026.

Your home may be repossessed if you do not keep up repayments on your mortgage or any other debts secured on it.

Easy Street Financial Services Limited is authorised and regulated by the Financial Conduct Authority. FCA No. 1013595.