Overpaying your mortgage

A mortgage overpayment is an extra payment on top of your standard monthly mortgage payment¹. It can be a small regular amount each month, a one-off lump sum, or a mix of the two. The money goes straight at the debt, so every pound overpaid stops generating interest from that point onwards.

The effect can be large. On a £200,000 mortgage with 30 years left at a 5% rate, overpaying £100 a month would cut more than five years off the term and save £37,314 in interest; £250 a month would cut 10 years and 1 month and save £70,796². Most deals allow overpayments of up to 10% of the balance each year without a charge², and going beyond that typically triggers an early repayment charge of 1% to 5% of the excess³.

What a mortgage overpayment is

An overpayment is any repayment over and above the monthly mortgage payments your lender requires⁵. On a repayment mortgage, your normal monthly payment covers both interest and a slice of the loan itself; an overpayment is extra money that reduces the balance directly¹. Lenders describe it simply as paying a bit extra on top of your usual monthly payment⁶.

Overpayments come in two forms, and most lenders accept both. A regular overpayment is a fixed extra amount paid every month, often set up by standing order alongside the normal payment⁷. A lump sum overpayment is a one-off payment, perhaps from a bonus, an inheritance or savings. Which suits you is a matter of cash flow rather than mechanics: the interest saving comes from the balance falling sooner, whether that happens in instalments or at once.

Overpaying is different from remortgaging or borrowing more. It does not change your interest rate or your deal; it simply shrinks the debt the rate is charged on. It is also different from shortening your term on paper: with an overpayment you keep your contractual monthly payment and pay extra on top, which you can usually stop or adjust if your circumstances change, whereas a formally shortened term commits you to a higher required payment each month.

The mechanics matter for one group in particular. Overpaying only reduces the amount you owe on a repayment mortgage, where each payment is partly paying off the loan itself. If you have an interest-only mortgage, your monthly payments cover interest only and the loan is repaid at the end from elsewhere; to pay the debt down early through the mortgage itself, you would need to switch to a repayment mortgage first⁸.

What overpaying £50 to £250 a month saves on a £200,000 mortgage

The numbers below come from a worked example: a £200,000 mortgage with 30 years left to run and an interest rate of 5%². Left alone, that mortgage takes the full 30 years to clear and costs £386,512 in total, of which £186,512 is interest². Overpayments attack the interest in two ways: the balance falls faster, and because the balance is smaller, less interest accrues each month for the rest of the term.

The pattern in the table is worth noticing. Doubling the overpayment does not double the saving, because the biggest gains come early, when the balance is largest. Even £50 a month, less than £2 a day, takes nearly three years off this mortgage and saves over £20,000². Other published examples land in the same territory: an overpayment of £100 a month on a £200,000 mortgage could shave more than three years off the term and save around £10,000 in interest⁹, and on a £300,000 mortgage over 25 years at 5%, overpaying £90 a month would clear the debt in 22 years and 9 months, saving over two years' worth of payments¹⁰.

Lump sums work on the same principle. On a £200,000 mortgage over 25 years at 3%, a one-off £5,000 overpayment would see the mortgage repaid after 24 years and one month, saving £5,446 in interest, while a £20,000 overpayment would see it repaid after 21 years and 6 months, saving £20,155¹¹. The same payments taken as lower monthly payments instead would save less interest: £2,113 for the £5,000 overpayment and £8,453 for the £20,000 overpayment¹¹. The difference is the point: keeping the monthly payment unchanged squeezes far more out of the same money.

Shorter term or lower payments: how the lender applies the money

Overpaying does not automatically change anything about your mortgage. Lloyds Bank, for example, states that any overpayments will not automatically reduce your mortgage term or your monthly payment⁷. What happens next depends on what you ask for, and it is worth being explicit with your lender each time you overpay.

There are two options. The first is to keep your monthly payment as it is: the overpayment then reduces the mortgage term, and regular overpayments could help you become mortgage-free earlier, provided you maintain your normal monthly payment as well as your overpayment¹. This is the option behind the savings in the table above. The second is to ask the lender to recalculate your payment: the term stays the same and the monthly payment falls, which lowers your payments and makes them more affordable¹². The same £5,000 or £20,000 lump sum produces a smaller interest saving this way because the debt is cleared more slowly¹¹.

Neither option is locked in for ever, and the flexibility runs both ways. Borrowers struggling with payments can move in the opposite direction: under the Mortgage Charter, lenders can extend your mortgage term to reduce your monthly payments¹³, and after a payment holiday the whole mortgage still has to be repaid, either by increasing monthly payments or extending the term¹⁴. Overpaying when finances allow and extending the term when they do not are two uses of the same lever, and a lender may permit both at different points in the same mortgage.

The overpayment allowance: usually up to 10% a year

Most mortgages allow you to overpay a certain amount, usually around 10% of the balance per year, without incurring any additional charges¹⁰. The allowance is a percentage of your outstanding balance each year, not of the original loan, so it shrinks as the mortgage is paid down⁶. On a £200,000 mortgage, a 10% overpayment in the first year would be £20,000¹.

The 10% figure is consistent across lenders and independent sources, but it is a typical figure, not a rule:

• Most fixed-rate mortgages allow you to overpay up to 10% of the balance each year, either in regular overpayments or on an ad-hoc basis, and overpaying more in a 12-month period may trigger an early repayment charge¹⁵.
• Most lenders allow you to overpay up to 10% of your mortgage balance each year without paying an early repayment charge³.
• Most lenders allow you to overpay by a certain amount, typically 10% of your mortgage, each year without charge¹⁶.
• Many lenders let you overpay a fixed-rate mortgage by around 10% each year⁴.
• Some lenders, but not all, let you overpay a 10-year fixed-rate mortgage by up to 10% each year without a fee¹⁷.
• Most offset mortgages allow overpayments, often up to 10% of the balance per year without a charge¹⁸.
• Most lenders allow overpayments of up to 10% of your outstanding balance each year without charging a penalty¹⁹.

The allowance is genuinely near-universal but not guaranteed. A survey of the market found that 70% of current mortgage deals allow overpayments of up to 10% of the balance each year²⁰, which means a substantial minority of deals allow less, or charge sooner. The limit is usually 10% of the mortgage balance each year²¹, and your own limit is stated in your mortgage terms; if in doubt, your lender can confirm it.

Two details catch people out. First, the allowance usually resets each year: money not used in one year generally cannot be carried into the next, though the exact rules vary by lender. Second, the allowance applies during the initial deal period, and the picture changes completely once that period ends, as the next sections explain.

Early repayment charges: typically 1% to 5% of the balance

Go over the allowance, or repay the mortgage early in other ways, and an early repayment charge (ERC) may apply. The charge is usually 1% to 5% of the amount over the 10% threshold³. In other words, if your allowance is £20,000 and you overpay £25,000, the charge applies only to the £5,000 excess, not to the whole payment.

The size of the charge varies between lenders and usually steps down over the deal. On a five-year fix, the ERC might be 5% of your mortgage balance in year one, 4% in year two, 3% in year three, and so on²². Charges can be as much as 5% of the mortgage balance in the first year of a deal, and reduce the longer you have the deal²³. ERCs can be hefty, potentially reaching 5% of the amount repaid in the first year of a mortgage deal²⁴. The charge can take the form of either a flat percentage of the total loan or a fixed fee²⁵.

The scale of the charge matters because it can wipe out the benefit of overpaying. An ERC is generally calculated as a percentage of the outstanding loan and so can be a significant outlay: a 5% ERC on a £200,000 mortgage works out at a £10,000 penalty charge, which would erode some of the equity in the home²⁶. An ERC will not usually be charged once you have finished the initial period and moved onto your lender's standard variable rate²⁶. The same charges apply if you remortgage during the initial fixed or tracker period of your mortgage²⁶, and they can apply when porting is not possible and you repay early, at anything from 1% to 5% of the remaining balance¹⁹.

There are rules on what a lender can charge. Under the FCA's mortgage rules, an early repayment charge must be able to be expressed as a cash value and be a reasonable pre-estimate of the costs the lender incurs from the customer repaying early²⁷. The FCA defines the charge as one levied by the mortgage lender on the customer where the loan is repaid in full or in part before a date or event specified in the contract²⁸. Where a charge applies, the explanation you receive must state whether it applies, how it is calculated, and the maximum amount in cash terms that you might be expected to pay²⁹.

Lenders must also tell you about the charge properly, and the Financial Ombudsman Service has upheld complaints where they did not. In one case study, a customer redeemed a mortgage and found there was a £1,500 early repayment charge that had not been taken into account³⁰. If you believe a charge was not properly disclosed, you can complain to your lender and then to the Financial Ombudsman.

The same principle applies to other products, sometimes more harshly. Repaying equity release early often triggers an early repayment charge³¹, and in some cases these charges can be as high as 25%³². Buy-to-let mortgages work similarly: Precise Mortgages allows lump sum or regular overpayments, but an early repayment charge may apply within the early repayment charge period, and the borrower must confirm the payment is intended to repay the mortgage and reduce the interest-charged balance³³. The charge will be a percentage of the amount repaid, with the details set out in the mortgage illustration and mortgage offer³³.

On the standard variable rate: usually no limit

Once your initial deal period ends and you move onto your lender's standard variable rate (SVR), the overpayment picture changes completely. When you are on a standard variable rate there is usually no limit for mortgage overpayments⁴. An ERC will not usually be charged once you have finished the initial period and moved onto the SVR²⁶.

Lenders confirm this in their own terms. Lloyds Bank states that where early repayment charges do not apply, you can overpay as much as you like without being charged an ERC, though there might be other fees if you pay off your mortgage in full⁷. This makes the SVR period, or any deal without an ERC, the natural window for large lump sum overpayments: the money goes straight at the balance with no charge to erode the benefit.

The timing is worth planning around. A borrower with a large lump sum and a fixed deal that ends in a few months may find it costs nothing to wait, overpaying up to the allowance now and the rest once the deal ends. A borrower with years left on the deal may judge that the interest saved by overpaying now outweighs a charge on the excess, but that is a calculation to make with the exact charge figure from the lender, not a rule of thumb. The dedicated guide to early repayment charges covers how these charges are worked out in more detail.

Overpaying or saving: the guaranteed return and tax position

Overpaying is often compared with saving, because both put spare money to work. The comparison has a clear logic: the interest you avoid paying on your mortgage is a guaranteed return, since the rate you are charged is known, whereas savings rates change and investment returns are not guaranteed. There is also no tax on the savings you make by overpaying your mortgage², whereas interest earned on savings may be taxed above your personal savings allowance.

The counterweight is access. Money paid into a mortgage is money you can only get back by borrowing again, for example through a further advance or a remortgage, which takes time, costs fees and depends on the lender's agreement at that moment. Money in savings stays yours to spend. This is why the standard order of priorities is to keep an emergency fund first and overpay second, and the comparison page on overpaying versus saving sets the two options side by side.

One mortgage type blurs the line. An offset mortgage links your savings to your mortgage: the savings balance reduces the interest you pay, but the savings remain accessible, effectively letting you "borrow back" without a new application. Offset mortgages will often allow overpayments as well, though early repayment charges may apply¹¹. For people who want the interest saving of overpaying without losing access to the money, an offset mortgage is the structured version of that trade-off, and most offset mortgages allow overpayments of up to 10% of the balance per year without a charge¹⁸.

Before overpaying: the points to check

Overpaying is usually straightforward, but a short checklist avoids the expensive mistakes:

1. Check your allowance. Most lenders allow up to 10% of the outstanding balance each year without a charge⁶, but a deal may allow less. The lender can confirm the exact figure.
2. Check the charge for exceeding it. The charge is usually 1% to 5% of the outstanding balance³. The maximum amount in cash terms must be stated in the explanation of the charge²⁹.
3. Say what you want the money to do. Overpayments do not automatically reduce the term or the monthly payment⁷, so the lender needs to be told whether a shorter term or a lower payment is wanted.
4. Check your deal type. On a fixed rate, overpaying is limited to around 10% each year within the initial deal period¹; on the standard variable rate there is usually no limit⁴.
5. Check your mortgage type. On an interest-only mortgage, overpaying the monthly payment does not pay down the loan; a switch to a repayment mortgage does that⁸. Most lenders allow interest-only borrowers to overpay up to 10% of the outstanding mortgage per year before penalties, but the terms of the agreement set the exact position³⁴.
6. Keep a record. The annual mortgage statement shows the balance and payments²¹, which shows how much allowance has been used this year.

Whether an overpayment is the right use of a particular sum depends on circumstances. On a higher rate, the guaranteed saving from overpaying is larger; where costlier debts exist elsewhere, clearing those saves more. And where overpaying is being considered because current payments are unaffordable, that is a different problem: lenders have options such as extending the term to reduce monthly payments¹², and free debt advice is available before arrears build.

Where to get help

Your lender is the first stop for anything about your own allowance, charges or how an overpayment will be applied. Lenders publish their overpayment rules and most will confirm the position over the phone before you make a payment⁶.

If you are overpaying from a position of strength but want independent input, a mortgage adviser or broker can model the effect on your term and payments. The page on mortgage advice explains what advisers do and what they cost.

If money is tight rather than spare, free help is available. StepChange, a debt advice charity, explains the options when mortgage payments are unaffordable, including extending the term to lower payments¹² and what happens after a payment holiday¹⁴. Business Debtline sets out the help available with mortgage payments, including Mortgage Charter options such as extending the term to reduce monthly payments¹³. Shelter gives housing advice on options such as switching from an interest-only to a repayment mortgage when the term is ending soon⁸.

If something has already gone wrong, for example a charge you were not told about, complain to your lender first and then to the Financial Ombudsman Service, which can look at cases where an early repayment charge was not properly disclosed³⁰. The ombudsman is free to use. More generally, the page on mortgage rules and your rights explains the protections around regulated mortgages.