Everything landlords need to know about Section 24 tax in 2025. Learn how mortgage interest relief changes affect your tax bill and what you can do about it.

Written by
Ben Luxon
PUBLISHED ON
November 19, 2025
UPDATED ON
July 13, 2026
READ TIME
0 min
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Last updated: July 2026
Section 24 is a UK tax rule (introduced by the Finance (No. 2) Act 2015) that stops individual landlords deducting mortgage interest and other finance costs from their rental income. Since April 2020 you pay income tax on your full rental income and instead claim a flat 20% basic-rate tax credit on finance costs. Section 24 can push higher-rate landlords into a bigger tax bill. It does not apply to limited companies.
Section 24 of the Finance Act 2015 fundamentally changed how UK landlords are taxed on their buy-to-let properties. Since coming into full effect in April 2020, Section 24 has significantly reduced mortgage interest relief for landlords, increasing tax bills across the sector, particularly for higher-rate taxpayers.
In this comprehensive guide, we explain everything you need to know about Section 24 tax, including how it works, who it affects, and what practical steps landlords can take to manage increased tax liability in 2026.
The Section 24 tax change restricts the amount of tax relief landlords can claim on mortgage interest and other finance costs. Before Section 24, landlords could deduct 100% of their mortgage interest payments from rental income before calculating tax. Now, landlords must pay tax on their full rental income and can only claim back a 20% basic rate tax credit on mortgage interest, regardless of whether they're a basic, higher, or additional rate taxpayer.
The rules were phased in gradually:
The government introduced Section 24 with several objectives:
Former Chancellor George Osborne argued that allowing landlords to offset mortgage interest gave them an unfair advantage in the housing market. Despite widespread opposition from landlord groups, Section 24 passed and remains in effect under the current Labour government, with no planned repeal as of June 2026.

The Section 24 tax changes apply to all residential buy-to-let landlords if they are one of the following:
Section 24 does not apply to commercial properties or to residential property owned by a registered company. Holiday lets, however, are no longer exempt: the Furnished Holiday Lettings regime was abolished from 6 April 2025 (see below).
Buy-to-let landlords are still allowed to deduct from their gross rent the allowable expenses, meaning expenses such as maintenance costs, can still be deducted from the gross rent and tax only needs to be paid on the rental income after that deduction.
A few allowable expenses include:
Relief on the following costs is now restricted and payments, cannot be deducted when calculating taxable profit. Instead, a percentage can be claimed back after the taxable profit has been worked out.
As you can see Section 24 affects most financing repayment claims, rather than ongoing property maintenance and management costs.
Related: Landlord Loopholes: 5 Ways To Reduce Buy-to-Let Property Tax
Essentially, under the Section 24 rules, landlords will need to pay income tax on almost all of their earnings from the property and then claim back a 20% of that interest as a tax relief.
Understanding how Section 24 affects your actual tax bill is crucial for landlords. The before-and-after comparisons below use the 2026/27 tax year bands — a personal allowance of £12,570 and a higher-rate threshold of £50,270 (both frozen) — to show the real financial impact.
Let's start with a straightforward scenario:
Your rental situation:
Before Section 24 (Pre-2020 Rules)
| Item | Amount |
|---|---|
| Rental income | £18,000 |
| Less: Mortgage interest | -£6,000 |
| Less: Other expenses | -£2,000 |
| = Taxable rental profit | £10,000 |
| Your other income | £30,000 |
| Total taxable income | £40,000 |
| Tax on rental profit (at 20%) | £2,000 |
After Section 24 (Post-2020 Rules)
| Item | Amount |
|---|---|
| Rental income | £18,000 |
| Less: Other expenses only | -£2,000 |
| = Taxable rental profit | £16,000 |
| Your other income | £30,000 |
| Total taxable income | £46,000 |
| Tax on rental profit (at 20%) | £3,200 |
| Less: 20% tax credit on £6,000 interest | -£1,200 |
| = Net tax you pay | £2,000 |
Result: In this scenario, you're still a basic-rate taxpayer so Section 24 doesn't increase your tax bill.
The Section 24 tax change hits hardest when it pushes you into a higher tax bracket. Here's where the real damage occurs:
Your rental situation:
Before Section 24
| Item | Amount |
|---|---|
| Rental income | £30,000 |
| Less: Mortgage interest | -£15,000 |
| Less: Other expenses | -£3,000 |
| = Taxable rental profit | £12,000 |
| Your other income | £45,000 |
| Total taxable income | £57,000 |
| Tax breakdown: | |
| - First £50,270 at 20% | £10,054 |
| - Remaining £6,730 at 40% | £2,692 |
| Total tax on rental profit | £2,400 (approx) |
After Section 24
| Item | Amount |
|---|---|
| Rental income | £30,000 |
| Less: Other expenses only | -£3,000 |
| = Taxable rental profit | £27,000 |
| Your other income | £45,000 |
| Total taxable income | £72,000 |
| Tax breakdown: | |
| - First £50,270 at 20% | £10,054 |
| - Remaining £21,730 at 40% | £8,692 |
| Tax on rental portion (approx) | £6,000 |
| Less: 20% tax credit (£15,000 × 20%) | -£3,000 |
| = Net tax you pay | £3,000 |
Result: Your tax bill has increased by £600 per year (from £2,400 to £3,000). A 25% increase.
The higher-rate problem: Your total taxable income jumped from £57,000 to £72,000, pushing £21,730 more into the 40% tax bracket instead of just £6,730.
Use these steps to estimate your Section 24 impact:
Step 1: Calculate your gross rental income (total rents received)
Step 2: Deduct allowable expenses (excluding mortgage interest)= Your taxable rental profit under Section 24
Step 3: Add this to your other income (salary, pension, etc.)= Your total taxable income
Step 4: Calculate tax on this total using current tax bands
Step 5: Calculate your 20% tax credit: Mortgage interest × 20%
Step 6: Subtract the tax credit from your total tax bill= Your final tax liability
Compare this to what you'd pay under the old rules (where mortgage interest was deductible) to see your Section 24 increase.
Calculating the amount of taxable profit on your rental property can be a fairly complex issue, so it’s well worth consulting with a licensed professional to get financial advice and ensure that you are calculating and paying the right amount.
Your Section 24 tax calculation doesn't exist in isolation. All income sources count when determining your tax bracket:
Example: Even if your rental profit is only £15,000, if you have a £40,000 salary, your total taxable income is £55,000, which pushes you into that higher-rate bracket where Section 24 hurts most.

Until April 2025, Furnished Holiday Lettings (FHLs) were exempt from Section 24 restrictions, making them significantly more tax-efficient than standard buy-to-let properties. However, this exemption has been abolished.
The government scrapped the Furnished Holiday Letting tax regime entirely. From 6 April 2025:
If you operate holiday lets, you now face:
Many holiday let owners are now considering:
If you purchased holiday lets specifically for the tax advantages, we strongly recommend consulting with a qualified tax adviser about your options.
For landlords with smaller rental income and portfolios, the effects of Section 24 may be reasonably minimal. For landlords with bigger portfolios, however, these tax implications could be large so it’s well worth considering potential actions that could be taken to reduce the impact of Section 24. For a fuller rundown, see our guide to tax-saving strategies for UK landlords.
Making Tax Digital (MTD) for Income Tax represents another major change coming for UK landlords. Originally scheduled for 2024, the rollout has been delayed and will now be phased in from 6 April 2026.
MTD requirements are being introduced gradually based on your gross rental income:
Note: This is your qualifying gross income (total rental income before expenses), not your profit. If you jointly own properties, each owner's share counts towards their individual threshold.
Once MTD applies to you, you'll need to:
With the first compliance deadline approaching in April 2026, landlords should:
Some landlords may be exempt if:
However, exemptions are limited—most landlords will need to comply.
Read the full Landlord's Guide to MTD Here
Yes. Section 24 has been fully in force since the 2020/21 tax year and remains in effect in 2026, with no planned repeal. Individual landlords cannot deduct mortgage interest from rental income and instead receive a 20% basic-rate tax credit on finance costs.
No. Section 24 only applies to individual landlords. Limited companies can still deduct mortgage interest as an allowable business expense and pay Corporation Tax on their net profit, which is why many landlords consider investing through a limited company.
Common approaches include incorporating into a limited company, transferring ownership (or a share) to a lower-earning spouse to use their tax bands, keeping allowable expenses efficient and well-recorded, and reviewing portfolio profitability. Each has trade-offs, so take professional advice. See our full guide to tax-saving strategies for UK landlords.
Yes, since 6 April 2025. The Furnished Holiday Lettings (FHL) regime was abolished, so holiday lets now face the same Section 24 mortgage-interest restriction as standard residential buy-to-let properties and only receive the 20% basic-rate tax credit on finance costs.
The 20% tax credit is the relief that replaced full mortgage interest deduction under Section 24. Rather than deducting finance costs from rental income, individual landlords calculate tax on their full rental profit and then reduce their tax bill by 20% of their finance costs (mortgage interest and similar). Higher and additional-rate taxpayers therefore get relief at only 20%, not their marginal rate.
Section 24 was phased in over four tax years. Landlords could deduct 75% of finance costs in 2017/18, 50% in 2018/19 and 25% in 2019/20, with the balance each year given as a 20% basic-rate tax credit. From the 2020/21 tax year onwards the restriction has been fully in force: no finance costs are deductible and individual landlords receive only the 20% tax credit.
Not if you own the property as an individual. Since April 2020, individual landlords cannot deduct mortgage interest or other finance costs from rental income. You pay tax on the full rental profit and then reduce your bill by a 20% tax credit on those finance costs. Landlords who own property through a limited company can still deduct mortgage interest in full as a business expense.
Yes. Section 24 is a UK-wide income tax rule, so it applies to residential landlords in England, Scotland, Wales and Northern Ireland. Scottish taxpayers pay Scottish income tax rates and bands on their rental profit, but the same restriction on finance costs and the 20% basic-rate tax credit still apply.
Section 24 doesn't exist in isolation. It's part of a broader regulatory shift that has fundamentally changed the economics of buy-to-let property investment in the UK.
Beyond Section 24, landlords in 2026 are facing multiple major changes:
Making Tax Digital – Quarterly digital submissions will replace annual tax returns for landlords with qualifying income over £50,000 from April 2026, requiring MTD-compatible software and significantly more administrative work throughout the year.
Renters' Rights Act – The abolition of Section 21 "no-fault" evictions, mandatory periodic tenancies, and stricter possession procedures will fundamentally change how landlords manage tenancies and recover their properties.
EPC Regulations – Proposed changes will require all rental properties to meet EPC Band C by 2030, with an estimated cost cap of £15,000 per property. Average upgrade costs are projected at £6,100-£6,800, though this varies significantly by property age and condition.
Ongoing Tax Pressures – High Capital Gains Tax, the 5% Stamp Duty surcharge on additional properties, and the potential for future tax increases (such as adding National Insurance onto rental income) targeting property investors all add to the financial burden.
Back in the day, spreadsheets and paper receipts were enough. Today though landlords face stricter rules than ever before. And the rules keep on changing, and not for the better. Which is why it's so important to ensure you have the right tools in your pocket. Landlord Studio can help you:
The landlords who succeed are the ones using smart digital tools, keeping meticulous records, and making data-driven decisions. Whether you manage one property or twenty, the right system isn’t just convenient, it’s how you survive and thrive in today’s market.
Create your free Landlord Studio account today, streamline your property management and maximise your investment returns.