Understanding Rental Business Mortgage Relief
Landlords often incur finance costs when purchasing, refinancing or improving rental properties. These costs may include:
- Mortgage interest
- Interest on loans used to purchase residential rental property
- Interest on borrowing used to repair or improve a rental property
- Interest on loans used to fund certain property business expenses
- Some mortgage arrangement, guarantee and finance-related fees
Historically, these costs could generally be deducted from rental income when calculating taxable profits. This reduced the amount of rental profit subject to Income Tax.
The current system is different for most individual landlords. Finance costs are normally excluded from deductible property expenses and instead used to calculate a separate basic-rate tax reduction.
Changes to Mortgage Interest Relief
The restriction on residential property finance costs was phased in from 6 April 2017 and became fully effective from 6 April 2020.
Under the current rules, most individual landlords cannot deduct residential mortgage interest and other qualifying finance costs from rental income before calculating taxable profit.
Instead:
- Rental profit is calculated before deducting restricted finance costs.
- The finance costs are identified separately.
- A tax reduction is generally calculated at the basic Income Tax rate of 20%.
- The reduction is applied against the Income Tax due on the property business.
This form of landlord mortgage relief is sometimes described as a mortgage interest tax credit, although HMRC refers to it as a basic-rate tax reduction.
How the Basic-Rate Tax Reduction Works
The Basic-Rate tax reduction is generally equal to 20% of the lowest of the following amounts:
- Qualifying finance costs for the tax year, including any unused costs brought forward
- Property business profits for the tax year
- Adjusted total income above the Personal Allowance
This restriction means the full amount of finance costs may not always generate an immediate tax reduction.
Unused residential finance costs can generally be carried forward and considered in a later tax year, provided the landlord continues to have the same type of property business.
Simple Example
A landlord receives £24,000 of rental income and has £8,000 of allowable non-finance expenses. The landlord also pays £6,000 of mortgage interest.
| Calculation | Amount |
|---|---|
| Rental income | £24,000 |
| Allowable non-finance expenses | £8,000 |
| Taxable rental profit before finance-cost reduction | £16,000 |
| Qualifying mortgage interest | £6,000 |
| Potential basic-rate tax reduction at 20% | £1,200 |
The taxable rental profit is £16,000, not £10,000. The £1,200 tax reduction is then deducted from the landlord’s Income Tax liability, subject to the statutory restrictions. For landlords with smaller rental income, it’s also worth checking whether the tax-free property allowance for landlords might offer a simpler alternative to itemising expenses altogether.
Why Higher-Rate Landlords May Pay More Tax
The current mortgage relief for landlords system can particularly affect taxpayers whose income falls within the higher or additional Income Tax bands.
Before the restriction, a higher-rate taxpayer could effectively receive relief at 40% on qualifying mortgage interest because the interest reduced taxable rental profits.
Under the current rules, the tax reduction is generally limited to 20%.
Higher-Rate Taxpayer Example
A landlord has £20,000 of rental income, £5,000 of non-finance expenses and £8,000 of mortgage interest.
- Taxable property profit is £15,000.
- Income Tax at 40% is £6,000.
- The potential finance-cost tax reduction is £1,600.
- The resulting tax after the reduction is £4,400.
If mortgage interest had been fully deductible, the taxable profit would have been £7,000 and the Income Tax at 40% would have been £2,800.
Which Landlords Are Affected?
- Individuals who let residential property
- Sole landlords
- Individuals in property partnerships
- Trustees or beneficiaries in some residential property businesses
- Non-resident individuals with UK residential property income
The rules do not generally apply in the same way to companies carrying on a property rental business, commercial property finance costs, or property dealing and development businesses. The finance-cost restriction also doesn’t apply in the same way to someone simply letting a room in their own home, where a different set of rules around tax-free income from letting a room in your home may be more relevant.
Qualifying Finance Costs
- Interest on a loan used to purchase a residential rental property
- Interest on additional borrowing used for repairs or improvements
- Interest on a loan used to refinance original qualifying borrowing
- Mortgage arrangement fees treated as finance costs
- Loan guarantee fees
- Interest on overdrafts used wholly for the property business
Separately from finance costs, landlords who replace furnishings such as beds, sofas or white goods may also be able to claim under replacement of domestic items relief.
The purpose of the borrowing is more important than the property used as security. Interest on a loan secured against a landlord’s home may qualify where the funds are used wholly for the rental business, while interest on borrowing secured against a rental property will not qualify where the money is used privately.
Costs That Do Not Qualify for Mortgage Relief
- Mortgage capital repayments
- Private borrowing costs
- Interest not connected with the property business
- Penalties for late mortgage payments
- Finance costs already relieved elsewhere
While mortgage interest is restricted in this way, landlords can still claim a wide range of other allowable running costs our broader roundup of tax deductions landlords should know about covers these in full.
Can Refinancing Interest Qualify?
Interest on replacement borrowing may qualify where it replaces an earlier loan used for the property business. Relief can be limited where the refinanced loan exceeds the capital originally introduced into the property business or where additional funds are withdrawn for private use.
Mortgage Relief and Jointly Owned Property
Where a property is jointly owned, rental income and finance costs must be allocated between the owners. Married couples and civil partners who live together are generally taxed equally on jointly owned property income unless a valid declaration based on unequal beneficial ownership applies.
Each owner applies the tax reduction separately based on their share of rental income, property profit, qualifying finance costs and wider Income Tax position.
Mortgage Relief for Limited Companies
Companies are not generally subject to the same residential property finance-cost restriction. A property company can normally deduct qualifying interest and finance expenses when calculating taxable property business profits, subject to Corporation Tax rules and any relevant restrictions.
This does not automatically make incorporation more tax-efficient. A full comparison should consider Corporation Tax, tax on extracting profits, Stamp Duty Land Tax, Capital Gains Tax, refinancing costs, borrowing rates, administrative costs and succession planning. Decisions like this are best made as part of a wider strategy to maximise your rental property ROI through effective tax planning, rather than in isolation.
Furnished Holiday Lettings and Mortgage Interest
The separate furnished holiday lettings tax regime was abolished from 6 April 2025 for Income Tax and Capital Gains Tax purposes, and from 1 April 2025 for Corporation Tax. Former furnished holiday letting businesses operated by individuals are therefore generally subject to the same residential finance-cost restriction as other residential property businesses from 2025/26 onwards.
Mortgage Relief and Property Losses
Property business losses and unused residential finance costs are tracked separately. A landlord may therefore carry forward both a property loss balance and an unused finance-cost balance, with each subject to different rules.
Effect on Adjusted Net Income
Because residential mortgage interest is no longer deducted when calculating taxable rental profits, adjusted net income can be higher than under the old system. This can affect the Personal Allowance taper, High Income Child Benefit Charge, tax-free childcare eligibility, savings tax and pension planning.
Reporting Mortgage Relief on Self Assessment
Individual landlords should distinguish rental income, allowable non-finance expenses, residential finance costs, unused finance costs brought forward and property losses brought forward.
Entering mortgage interest as an ordinary deductible expense can understate taxable property profit and produce an incorrect return. Annual mortgage statements should be used because monthly repayments usually include both interest and capital.
Records Landlords Should Keep
- Annual mortgage interest statements
- Loan and refinancing agreements
- Mortgage completion statements
- Bank statements
- Finance fee invoices
- Evidence showing how borrowed funds were used
- Rental income and property expense records
- Schedules of unused finance costs carried forward
Common Mortgage Relief Mistakes
- Deducting residential mortgage interest directly from rental income
- Claiming relief for mortgage capital repayments
- Using total monthly repayments instead of the interest figure
- Assuming relief always equals 20% of all finance costs
- Ignoring the property profit and adjusted income restrictions
- Failing to carry forward unused finance costs
- Claiming interest on borrowing used privately
- Applying company tax treatment to an individually owned property
Is There a Mortgage Relief Program for Landlords?
There is no general HMRC mortgage relief program that reimburses buy-to-let mortgage payments. The relevant tax provision is the basic-rate reduction for qualifying residential property finance costs.
Landlords experiencing difficulty paying a mortgage should contact their lender directly. Lender support, refinancing and forbearance arrangements are separate from the tax rules.
Final Guidance on Mortgage Relief for Landlords
Mortgage relief for individual residential landlords is generally provided as a 20% basic-rate tax reduction rather than a direct deduction from rental income.
The result depends on qualifying finance costs, property profits, adjusted total income and the landlord’s wider tax position. Accurate records and separate tracking of unused finance costs are therefore essential.
Mortgage Relief for Landlords Case Study
David, an individual landlord, visited our Wimbledon office after noticing that his Self Assessment tax bill had increased despite paying substantial mortgage interest on his rental property. He assumed his mortgage interest could still be deducted from his rental income, but he was unsure how the current mortgage relief for landlords rules applied or whether he was claiming the correct tax relief.
After reviewing David’s rental accounts, mortgage statements and finance costs, we explained how mortgage relief UK rules now operate for individual residential landlords. We clarified that qualifying mortgage interest is no longer deducted from rental income when calculating taxable profits. Instead, eligible finance costs are generally used to calculate a 20% basic-rate tax reduction, subject to HMRC’s statutory limits. We also checked whether any unused finance costs could be carried forward and reviewed how the revised rules affected his overall Income Tax position as a higher-rate taxpayer.
During the consultation, we highlighted common mistakes, such as claiming capital repayments instead of mortgage interest or using total monthly mortgage payments rather than the interest element shown on annual mortgage statements. We also discussed the importance of maintaining accurate records to support future HMRC reporting.
By the end of the meeting, David understood how to claim mortgage relief for landlords correctly, maintain accurate rental records and ensure his property tax affairs remained fully compliant with HMRC requirements.
