Fixed-rate mortgages
Fixed-rate mortgages are the type most likely to have a 10% cap. During the fixed period, lenders often allow overpayments but limit how much you can repay early without a fee.
Mortgage Overpayment Limit UK (10% Rule Explained + Real Examples)
By Mortgage Overpay Editorial Team, mortgage content specialist | Last updated: April 2026
Most UK mortgages allow around 10% of the outstanding balance to be overpaid each year without penalty during a fixed deal. Go above that and you may face an early repayment charge, often called an ERC. Some mortgages allow more and some allow less, so the exact overpayment limit depends on your lender and mortgage terms.
Quick Answer
If you want the shortest version first, these are the points that matter most.
- Most UK mortgages allow up to 10% overpayment per year during a fixed deal.
- This is usually based on your outstanding balance, not the amount you originally borrowed.
- Going over the limit may trigger early repayment charges, often called ERCs.
- Limits vary depending on your mortgage type, so always check your mortgage terms before making a larger payment.
What Is the Overpayment Limit in the UK?
The overpayment limit is the extra amount a lender lets you pay off without triggering a charge.
An overpayment allowance is the amount you can pay above your normal monthly mortgage payment within a defined period. On many fixed-rate mortgages, that allowance is around 10% of the outstanding balance each year.
Most UK lenders allow around 10%, but the exact limit varies by lender, mortgage type, and deal terms. Some mortgages are more flexible. Some are tighter. Some have no practical cap once a fixed period ends.
So the short answer is straightforward: many borrowers can overpay around 10% a year, but the exact amount on your mortgage depends on your own paperwork.
This matters because overpaying can reduce your balance faster, cut the total interest you pay, and potentially help you become mortgage-free sooner. But it only works well if you understand the rules first.
The 10% Mortgage Overpayment Rule Explained
The 10% rule is simple once you strip away the jargon.
On many fixed-rate mortgages, you can overpay up to around 10% of the outstanding mortgage balance in a mortgage year without paying an ERC.
The most important point is that the allowance is usually based on what you still owe, not what you originally borrowed. So if your remaining balance is £180,000, a typical 10% allowance could mean you can overpay around £18,000 in that mortgage year without penalty.
The allowance usually resets yearly. That does not always mean a calendar year. Some lenders use the mortgage anniversary, some use the product anniversary, and some define the year in their own way.
In most cases, the lender works out the allowance using the outstanding balance at the start of the allowance period. That means the 10% figure is normally set from one starting balance rather than changing every time the balance moves during the year.
Unused allowance usually cannot be carried over. If you do not use your full allowance this year, you normally do not get to add the unused part to next year.
In practice, the 10% rule is a useful guide, but it is not a substitute for checking the wording of your own deal. Always check your mortgage terms before making a larger overpayment.
Real Example: How the 10% Overpayment Limit Works
A simple example makes the 10% rule much easier to understand.
Imagine your mortgage balance is £200,000. If your lender allows 10% overpayment in the year, your allowance would usually be £20,000.
If you then make an overpayment of £25,000, the first £20,000 would normally fall within the allowance and would usually not trigger a charge.
The remaining £5,000 would be the part above the limit. In most cases, that is the amount the ERC would be calculated on.
In other words, the charge usually applies only to the excess, not to the full overpayment. That is an important detail because it makes the rule less confusing and helps you estimate the real cost of going over your limit.
Mortgage balance
£200,000
10% allowance
£20,000
Overpayment made
£25,000
ERC applies to
£5,000
The first £20,000 falls within the allowance. The extra £5,000 sits above the limit, so that is the part that would usually be checked for an early repayment charge.
Example Overpayment Limits (Real Numbers)
The table below shows what a typical allowance looks like in practice.
| Mortgage Balance | 10% Annual Limit | Monthly Equivalent |
|---|---|---|
| £100,000 | £10,000 | £833 |
| £200,000 | £20,000 | £1,666 |
| £300,000 | £30,000 | £2,500 |
This is the easiest way to understand how much you can overpay. If your remaining balance is £100,000, a typical 10% annual allowance could mean £10,000 of extra repayments in that year. If your balance is £200,000, the allowance could be around £20,000. If it is £300,000, it could be around £30,000.
The monthly equivalent is only a guide. Your lender usually cares about the yearly total, not whether you send the money monthly or as one lump sum. So you could often use a mix of regular overpayments and one-off payments, as long as the total stays within the annual limit.
This is why some borrowers choose a steady monthly overpayment, while others wait for a bonus or savings build-up and make one larger lump sum payment instead.
What Happens If You Go Over the Limit?
If you go above the allowance while charges still apply, you may have to pay an ERC.
An early repayment charge is usually a percentage fee. A typical range is around 1% to 5%, although the exact number depends on the deal and how far through the restricted period you are. If you want a plain-English overview, MoneyHelper explains early repayment charges clearly.
In many cases, the ERC applies only to the amount above the limit, not to the whole overpayment. That point matters because it helps you work out the real cost of exceeding your allowance.
Example
- £200,000 mortgage
- £20,000 limit
- £25,000 overpayment
- ERC applies to £5,000 only
So if your lender charged 3% on the excess, the fee would be worked out on the £5,000 above the allowance, not on the full £25,000. That still reduces the value of overpaying, which is why it is worth checking first.
As another simple example, a 2% ERC on £5,000 would cost £100. That is why many borrowers prefer to stay inside the allowance unless they have checked that going over still makes financial sense.
Going over the limit does not always mean overpaying is a bad idea, but it does mean you should compare the likely interest saving with the likely charge before acting.
Mortgage Types and Overpayment Rules
The answer changes a lot depending on the kind of mortgage deal you have.
Tracker mortgages
Tracker mortgages often have more flexibility and may have no overpayment limit, but you still need to check the terms. Some trackers are flexible, while others still have restrictions.
Standard variable rate (SVR)
Standard variable rate mortgages are usually more flexible and often have no practical limit on overpayments, but again the only reliable answer is the wording in your own mortgage conditions.
Can You Overpay More Than 10%?
Yes, but whether you can do it cheaply depends on the mortgage type and whether ERCs still apply.
Sometimes you can overpay more than 10%. Some flexible mortgages allow it. Some tracker or SVR mortgages may allow unlimited overpayments. And once a fixed period ends, the old cap may disappear altogether.
The practical catch is that if you are still inside a restricted period and your mortgage uses a 10% annual allowance, going above it may trigger an ERC on the excess.
That means overpaying more than 10% is often possible, but not always sensible. The best time to consider a large overpayment is often when:
- your fixed deal is ending soon
- you have moved to a more flexible mortgage type
- your lender has confirmed no ERC applies
- your mortgage is specifically designed to allow larger overpayments
If you are planning a big lump sum, it is worth checking whether waiting a little longer could move you into a more flexible part of the mortgage and save you a charge.
Important Edge Cases Most People Miss
A few practical details can change how the overpayment limit works in real life.
At the end of a fixed-rate deal: overpayments usually become much more flexible once the deal ends. In most cases, the old cap no longer applies in the same way, and overpayments may become unlimited if you move onto a more flexible rate.
If you switch mortgage deals mid-year: the allowance may reset, change, or be replaced with a new overpayment rule depending on the lender and the new product. Always check your mortgage terms rather than assuming the old allowance carries across neatly.
If your mortgage has multiple parts: each part may have its own balance, rate, and overpayment limit. In that situation, the allowance on one part may not be the same on another.
These edge cases are easy to miss, especially if you are focused only on the headline 10% rule. A quick check before making a larger payment can remove a lot of uncertainty.
Monthly vs Lump Sum Overpayments
Both methods can work well, and both usually count toward the same annual allowance.
Monthly overpayments
Monthly overpayments are small extra amounts added to your normal payment. They are often easier to budget for and easier to keep going consistently.
They work well if you want to reduce the balance steadily without making one large decision in one go.
Lump sum overpayments
Lump sum overpayments are one-off payments, often made from savings, a bonus, or another windfall. They can make a bigger immediate dent in the mortgage balance.
They work well if your spare money comes in larger chunks rather than month by month.
The main practical point is simple: monthly and lump sum overpayments usually count towards the same annual allowance.
So if you have already been paying an extra £200 a month and then decide to make a £5,000 lump sum payment, both amounts normally need to be counted together when checking whether you are still inside the yearly limit.
How to Check Your Overpayment Limit
If you want the real answer for your own mortgage, these are the three places to check first.
- Your mortgage offer document, where the overpayment allowance and ERC wording are often set out clearly.
- Your annual mortgage statement, which may show the current deal details and any overpayments already made.
- Your lender directly, if you want confirmation before making a larger monthly or lump sum overpayment.
If the wording is unclear, ask direct questions. For example: what is my current annual allowance, when does it reset, and would this exact payment trigger an ERC?
That is often the quickest way to remove uncertainty before you act. If you want broader consumer guidance, the FCA's mortgage information page is also a useful place to start.
How to Avoid Early Repayment Charges
The safest way to avoid an ERC is to plan your overpayments rather than treating the allowance as a rough guess.
- Stay within the 10% allowance. If your mortgage uses a 10% rule, keep a running total of all monthly and lump sum overpayments together.
- Check the reset date. The allowance usually resets yearly, but not always on 1 January.
- Time payments across years if needed. In some cases, splitting a larger overpayment across two allowance years can avoid a charge.
- Confirm the details before paying. A quick check with the lender can stop an avoidable ERC.
Most UK lenders allow around 10%, but the small details matter. A payment made a few days earlier or later can sometimes make the difference between staying inside the allowance and triggering a fee.
That is why borrowers making a larger overpayment often plan around the reset date rather than just around when they happen to have the cash available.
How Much Can You Overpay Without Penalty?
In most cases, the answer depends on your current balance, your mortgage type, and the lender rules that apply to your deal.
| Mortgage balance | Typical 10% annual overpayment limit |
|---|---|
| £100,000 | £10,000 |
| £200,000 | £20,000 |
| £250,000 | £25,000 |
| £300,000 | £30,000 |
In most cases, your exact limit depends on your current mortgage balance, mortgage type and lender rules. The safest approach is to check your mortgage terms before making a large overpayment.
Use our mortgage overpayment calculator to test your own numbers and see how much interest you could save.
Useful next steps
These guides help once you understand the limit and want to decide what to do with it.
Important note
This page is designed to be clear, practical, and factual rather than promotional.
This is general guidance only. Most UK lenders allow around 10% during a fixed period, but lender terms vary. Always check your mortgage offer, annual statement, or lender confirmation before making a larger overpayment.
FAQs
Quick answers to the most common questions about overpayment limits.
What is the 10% mortgage overpayment rule UK?
The 10% mortgage overpayment rule usually means you can overpay up to around 10% of your outstanding mortgage balance in a mortgage year without an early repayment charge. It is common on fixed-rate deals, but it is not universal.
Can I overpay my mortgage by more than 10%?
Sometimes, yes. Some tracker, flexible, or standard variable rate mortgages may allow more than 10%, and some borrowers gain more freedom once a fixed period ends. The exact answer depends on the mortgage terms.
Do all mortgages have overpayment limits?
No. Many fixed-rate mortgages do, but some tracker and standard variable rate mortgages may allow much more freedom. You should always check the mortgage offer or latest terms rather than assuming.
Are overpayments counted monthly or yearly?
On many mortgages, the allowance is measured over a mortgage year, not month by month. Monthly overpayments and lump sums often count towards the same yearly total.
What happens if I exceed my allowance?
If you go above the mortgage overpayment allowance while early repayment charges apply, the lender may charge an ERC. That charge is often a percentage of the amount above the limit rather than the whole overpayment.
Use our calculator to see exactly how much you can overpay without triggering charges and how much interest you could save
Test monthly and lump sum scenarios, compare realistic figures, and see what your allowance could mean in pounds and time saved.
Key Takeaways
If you only want the main points to remember, focus on these.
- Most mortgages allow around 10% overpayment each year during a fixed-rate deal.
- Going above the allowance may trigger an early repayment charge on the excess.
- Fixed deals usually have limits, while tracker and variable deals are often more flexible.
- The allowance usually resets yearly and unused allowance usually cannot be rolled forward.
- Always check your mortgage terms before making a larger overpayment.
Last updated: April 2026