Most UK homeowners cannot claim tax relief on mortgage interest paid on their main residence. However, different rules apply when a mortgage or loan is used for a residential letting business, commercial property or company-owned property.
An individual residential landlord cannot normally deduct mortgage interest directly from rental income. Instead, qualifying interest and finance costs may generate a basic-rate Income Tax reduction. Capital repayments do not qualify because they repay the amount borrowed rather than represent a financing cost.
Key Takeaways:
- Main-home mortgage interest does not normally qualify for personal tax relief.
- Individual residential landlords may receive a tax reduction on qualifying finance costs.
- The reduction is currently calculated at the 20% basic rate, subject to specific limits.
- Capital repayments, private borrowing and unrelated expenditure do not qualify.
- Companies and non-residential property businesses follow different rules.
- Separate property-income tax rates are due to apply from 6 April 2027 in England, Wales and Northern Ireland.
The correct treatment therefore depends on the property’s use, the borrower’s legal structure and how the borrowed money was spent.
Can Homeowners Claim Tax Relief On Mortgage Interest?
A UK homeowner cannot normally claim Income Tax relief for mortgage interest paid on a privately occupied main residence. The mortgage is treated as personal borrowing rather than a cost of earning taxable property income.
The former Mortgage Interest Relief at Source scheme no longer provides relief for ordinary residential mortgages. Buying a first home, choosing an interest-only mortgage or remortgaging an existing home does not normally change this position.
Occasionally, working from home also does not automatically make part of the mortgage interest deductible. A person running a substantial business from a specifically identified part of the property may need to consider separate expense, business-rates and Capital Gains Tax implications.
Support for Mortgage Interest is different. It is a government-backed loan available to some qualifying benefit claimants, not a deduction from taxable income.
Can Landlords Claim Tax Relief On Mortgage Interest?
Individual landlords can receive relief for qualifying finance costs relating to residential rental properties. Since 6 April 2020, the relief has been fully delivered as a basic-rate tax reduction rather than a direct deduction from rental income.
Who May Be Affected?
- UK-resident individuals with residential rental income.
- Non-resident individuals letting residential property in the UK.
- Individual members of property partnerships.
- Certain trustees or beneficiaries receiving residential property income.
- Owners of former furnished holiday lets after the special regime ended.
A landlord does not simply receive 20% of every mortgage payment back. Only qualifying interest and finance costs enter the calculation, and the available reduction can be limited by property profit, adjusted total income and Income Tax liability.
The restriction can affect higher-rate taxpayers particularly strongly because taxable property profit is calculated without deducting the restricted interest. This may move more income into a higher tax band even though a basic-rate reduction is later applied.
How Does Mortgage Interest Tax Relief Work For Individual Landlords?
How Is Taxable Rental Profit Calculated?
An individual landlord generally starts with gross rental income and deducts ordinary allowable expenses such as repairs, insurance, letting-agent fees and qualifying professional charges. Restricted residential finance costs are excluded from this initial calculation.
The landlord then calculates Income Tax on total taxable income. A separate reduction is applied for qualifying residential finance costs using the method set out in the official residential finance cost guidance.
For 2026/27, the reduction is generally 20% of the lowest of:
- Qualifying finance costs for the year plus eligible costs brought forward.
- Property-business profit after brought-forward property losses.
- Adjusted total income above the Personal Allowance, excluding savings and dividend income.
The official guidance states: “The tax reduction can’t be used to create a tax refund.”
How Is The Basic-Rate Reduction Limited?
The following historical case studies use the £11,000 Personal Allowance and tax bands applying in the original 2016/17 examples, 20% from £11,001 to £43,000 and 40% from £43,001 to £150,000. They illustrate the calculation but must not be treated as current tax thresholds.
Historical Calculation Examples
| Case | Income And Expenses | Calculation And Result |
|---|---|---|
| Sophia | Rent £52,000, interest £20,000 and other expenses £9,000 | Before restriction: profit £23,000 and tax £2,400. After restriction: profit £43,000; initial tax £6,400; £4,000 reduction; final tax £2,400. The test compared finance costs £20,000, profit £43,000 and adjusted income £32,000. The original estimate said 82% of landlords would pay no additional tax. |
| John | Self-employment £35,000, rent £18,000, interest £8,000 and other expenses £2,000 | Before restriction: property profit £8,000, total income £43,000 and tax £6,400. After restriction: property profit £16,000 and total income £51,000; £6,400 at 20% plus £3,200 at 40%, less a £1,600 reduction, produced £8,000 tax—an increase of £1,600. The test figures were £8,000, £16,000 and £40,000. The example’s £50,000 Child Benefit Charge reference is historical. |
| Jennifer | Employment £25,000, rent £11,000, interest £8,000 and expenses £500 | In 2017/18, 75% of interest—£6,000—was deductible. Profit was £4,500 and total income £29,500. Tax of £3,700 was reduced by £400, calculated on the remaining £2,000 of interest, leaving £3,300. The three test figures were £2,000, £4,500 and £18,500. |
| Brian, 2020/21 | Salary £36,000, rent £20,000, interest £15,000, repairs and expenses £7,000; empty for two months | Profit was £13,000 and total income £49,000. Tax was £6,400 plus £2,400, less a £2,600 reduction, giving £6,200. The test compared £15,000, £13,000 and £38,000, so £2,000 of finance costs was carried forward. |
| Brian, 2021/22 | Salary £36,000, rent £24,000, interest £15,000, expenses £2,000 and £2,000 brought forward | Profit was £22,000 and total income £58,000. Tax was £6,400 plus £6,000, less a £3,400 reduction, giving £9,000. The test compared total finance costs of £17,000, profit of £22,000 and adjusted income of £47,000. |
These cases demonstrate why the same amount of mortgage interest can produce different outcomes for landlords with different income and profit levels.
Which Mortgage Interest And Finance Costs Can Qualify For Tax Relief?
Qualifying costs may include interest on a buy-to-let mortgage, interest on a loan used for the property business, relevant overdraft interest and interest on borrowing used to buy furnishings.
Certain incidental costs of arranging or repaying finance may also qualify. These can include loan fees, commissions, guarantee fees and some charges connected with securing the borrowing, provided they relate to the property business.
The key test is how the borrowed money was used. A loan’s name or the property offered as security does not by itself determine whether the interest qualifies.
A landlord should retain the loan agreement, completion statement, annual interest certificate and bank records showing where the funds went. Without a clear transaction trail, it may be difficult to demonstrate that the borrowing related wholly to the property business.
How Are Capital Repayments, Personal Borrowing And Mixed-Use Loans Treated?
Only eligible interest and financing charges are considered. The capital element of a mortgage payment reduces the outstanding debt and does not qualify for the finance-cost reduction.
Costs requiring careful treatment:
- Capital mortgage repayments do not qualify.
- Interest connected with private expenditure does not qualify.
- Equity released and used personally may need to be excluded.
- Mixed personal and business borrowing must be apportioned.
- Loan penalties do not automatically qualify as finance costs.
- Interest above relevant property-business borrowing limits may be restricted.
- Refinanced borrowing must remain traceable to an allowable business purpose.
Where a property business includes residential and commercial elements, such as a shop with a flat above it, the finance costs must be divided on a just and reasonable basis.
The purpose and use of the borrowed funds during the period in which interest accrues are central to that allocation. Good records help establish the connection between the loan and the income-producing property activity.
Does Mortgage-Interest Tax Treatment Change For Companies, Commercial Property And Holiday Lets?
Can A Limited Company Deduct Mortgage Interest?
A company is not subject to the individual residential finance-cost restriction in the same way. Qualifying interest is normally considered under Corporation Tax and loan-relationship rules.
Company ownership is not automatically more tax-efficient. Corporation Tax, dividend or salary extraction, mortgage pricing, accountancy costs, filing duties, Stamp Duty Land Tax and potential Capital Gains Tax must all be considered before transferring or buying property through a company.
How Is Commercial Or Mixed-Use Property Treated?
Qualifying interest and loan-acquisition costs for a non-residential letting business may generally be deducted when calculating property profit. Current property-return notes distinguish these deductible non-residential costs from residential finance costs used to calculate a tax reduction.
Mixed-use loans require a reasonable allocation. Only the part relating to residential dwelling-house activity enters the individual residential finance-cost restriction.
Do Former Furnished Holiday Lets Follow Different Rules?
The special furnished holiday lettings regime ended from 6 April 2025 for Income Tax and Capital Gains Tax purposes, and from 1 April 2025 for Corporation Tax purposes.
Individual former holiday-let owners can generally obtain finance-cost relief at the basic rate, while companies remain outside the individual restriction. The official holiday letting tax update confirms the post-abolition treatment.
Older articles describing a full mortgage-interest deduction for individual furnished holiday lets may therefore no longer reflect current rules.
Can Unused Mortgage-Interest Tax Relief Be Carried Forward?
Unused residential finance costs may be carried forward when the reduction is limited by property-business profit or adjusted total income.
For example, if qualifying finance costs are £15,000 but property profit is only £13,000, the reduction may be calculated using £13,000. The remaining £2,000 can potentially be carried forward and included in a later year’s calculation.
Carried-forward costs remain attached to the same property business. They do not create an immediate repayment and may remain unused if later property profits or adjusted income are insufficient.
The Self Assessment property pages include separate entries for current residential property finance costs and unused costs brought forward. Current filing notes also state that an unrelieved balance may be carried forward to future years of the same property business.
Landlords should retain annual calculations showing how much relief was used and how much remains available.
How Should Mortgage Interest Be Reported On A Self Assessment Tax Return?
Residential finance costs should be recorded separately from ordinary property expenses. For the 2025/26 property pages, current finance costs are entered in box 44 and unused residential finance costs brought forward are entered in box 45.
Information to collect before filing:
- Total rent and other property receipts.
- Allowable non-finance expenses.
- Current-year mortgage interest and finance charges.
- Unused finance costs from earlier years.
- The taxpayer’s legal share of jointly owned income.
- Evidence showing how loans and remortgage proceeds were used.
- Property losses brought forward.
- Details of private or mixed use.
The current property return guidance should be checked for the relevant filing year because box numbers and forms can change.
A landlord using the £1,000 property allowance cannot also deduct ordinary expenses against the same income. The finance-cost reducer and property allowance also have specific interaction rules, so the two methods should be compared carefully.
Complete and consistent records make it easier to support the return if questions arise later.
What Mortgage-Interest Tax Changes Should Landlords Prepare For?
What Were The Transitional Percentages?
The restriction was introduced from 6 April 2017 and became fully effective from 6 April 2020. The deductible proportion decreased each year while the proportion eligible for the basic-rate reduction increased.
Finance-Cost Rule Timeline:
| Tax Year | Deductible From Rental Income | Eligible For Basic-Rate Reduction |
|---|---|---|
| 2017/18 | 75% | 25% |
| 2018/19 | 50% | 50% |
| 2019/20 | 25% | 75% |
| 2020/21 onwards | 0% | 100% |
| 2026/27 | 0% | 100% at the current 20% basic-rate calculation |
| From 2027/28 in England, Wales and Northern Ireland | 0% | Scheduled at the 22% property basic rate |
The transitional percentages are now historical, but they remain relevant when correcting older returns or reviewing carried-forward figures.
What Changes From 6 April 2027?
Separate rates for property income are set to apply in England, Wales and Northern Ireland from 2027/28: 22% at the property basic rate, 42% at the property higher rate and 47% at the property additional rate. Residential finance-cost relief is due to be calculated at 22%.
The future property income tax rules also change the ordering of property income in the Income Tax calculation.
For 2026/27, the standard Personal Allowance remains £12,570, the basic-rate limit is £37,700 and the higher-rate threshold is £50,270 for taxpayers using the main UK bands. Scottish Income Tax bands differ, and Scotland’s future property-income position should be checked separately.
Landlords should therefore use the rules for the actual tax year being reported rather than applying future percentages early.
Conclusion
Whether someone can claim tax relief on mortgage interest depends on the property’s purpose, its ownership and the use of the borrowed funds.
Mortgage interest on a privately occupied main home does not normally qualify. An individual residential landlord may receive a restricted tax reduction, currently based on 20% of the lowest applicable finance-cost, property-profit or adjusted-income figure.
Companies, commercial property and mixed-use borrowing require different treatment. Capital repayments remain excluded, while unused qualifying finance costs may sometimes be carried forward.
Because tax bands, filing forms and property-income rates can change, taxpayers should check the rules for the relevant year before submitting a return or restructuring property ownership.
FAQs
Can Mortgage Arrangement Fees Qualify For Landlord Tax Relief?
Certain fees incurred when obtaining or repaying qualifying property finance may be included. They must relate to the property business and meet the normal rules for incidental finance costs.
Can Interest On An Interest-Only Buy-To-Let Mortgage Qualify?
Yes, qualifying interest may enter the finance-cost calculation. The loan capital itself is not repaid through monthly interest payments and does not create an additional deduction.
Can Joint Property Owners Claim Relief Separately?
Each owner normally reports the appropriate share of property income, expenses and finance costs. The correct allocation depends on legal ownership, beneficial ownership and any applicable spousal or partnership rules.
Can Interest On A Personal Loan Used For A Rental Property Qualify?
It may qualify when the borrowed money is clearly used for the property business. The purpose and traceable use of the funds matter more than whether the lender labels the product a personal loan.
Can Interest Qualify While A Rental Property Is Empty?
It may continue to qualify where the property business remains active and the borrowing is still connected with that business. A temporary vacancy differs from permanently ending the letting activity.
Does The £1,000 Property Allowance Affect Finance-Cost Relief?
Yes. Choosing the property allowance changes how actual expenses are treated, and the finance-cost reduction cannot be combined casually with an allowance claim. The calculation should be compared under both available approaches.
Can A UK Taxpayer Claim Relief For An Overseas Rental Mortgage?
Potential relief may be available when overseas property income is taxable in the UK and the borrowing relates to that property business. Foreign tax, residence and double-taxation rules may also affect the final position.
Editorial Note
This article provides general UK tax information and does not consider every ownership, financing or residency arrangement. This is informational, not financial/legal advice. Tax treatment depends on individual facts and the rules applying in the relevant tax year. A qualified tax adviser should be consulted before filing, refinancing, incorporating or transferring property.
How We Checked?
The article was last checked on 15 July 2026 against current official landlord, property-return and property-income guidance. The historical calculations were compared with the published case studies and retained as historical illustrations rather than current tax-band examples. The supplied commercial reference articles were used to identify common reader questions, but official material took priority where wording or dates differed. Future-rate statements were checked against the published technical guidance and enacted 2026 legislation.
