Deductible expenses

Deductible expenses are the costs a landlord incurs in running their rental property that HMRC permits to be subtracted from rental income before taxable profit is calculated. According to gov.uk guidance on rental income, a cost is deductible only if it is incurred "wholly and exclusively for the purposes of renting out the property." This is the foundational test that determines whether any given landlord cost reduces the tax bill or does not.

Deductible expenses are sometimes called allowable expenses, the two terms are used interchangeably in landlord tax practice, though HMRC's formal documentation tends to use "deductible" in the context of specific schemes such as the Non-Resident Landlords Scheme. For day-to-day purposes, they refer to the same principle: qualifying costs that reduce taxable rental profit, and therefore reduce the income tax owed on that profit. A full explanation of how the two terms relate appears in the August entry on allowable expenses.

The wholly and exclusively rule

The phrase "wholly and exclusively" sets a strict standard. A cost qualifies only if the entire reason for incurring it was to run the rental business. Costs with a dual purpose, personal and business, are disallowable unless the business portion can be clearly separated and evidenced. A mobile phone used partly for personal calls, for example, can only be claimed to the extent that the calls relate to the rental property, and only if that proportion can be demonstrated. Costs incurred purely for personal reasons, even if they have some incidental connection to a rental property, do not pass the test.

Revenue expenditure versus capital expenditure

This distinction is one of the most consequential in landlord tax. Deductible expenses are revenue expenditure: costs that maintain the property in its existing condition and are incurred in the ordinary course of running the letting. They are fully deductible in the tax year in which they are paid.

Capital expenditure, by contrast, is spending that improves the property, extends its useful life, or adds something that was not there before. It is not deductible against rental income. Replacing a boiler with a like-for-like model is revenue expenditure. Installing underfloor heating where none existed is capital expenditure. Redecorating between tenancies is revenue expenditure. Fitting a new kitchen that substantially upgrades the original is capital expenditure. The distinction is not always obvious, and HMRC does not provide an exhaustive list, the test is applied to the specific facts of each cost.

Capital expenditure that cannot be set against rental income may reduce the capital gains tax liability when the property is sold, so records should be kept regardless.

What counts as a deductible expense

Costs that typically meet the wholly and exclusively test include letting agent fees, property management fees, landlord insurance premiums, maintenance and repairs (on a like-for-like basis), gas safety certificate fees, EICR costs, professional fees such as accountancy costs for preparing rental accounts, ground rent and service charges on leasehold properties, and council tax or utility bills paid by the landlord during void periods.

From working with self-managing landlords across the UK, the costs that are most consistently under-claimed are travel expenses to and from the rental property for management purposes, and the costs of compliance certificates. Both are fully deductible, and both are commonly omitted from self-assessment returns.

Finance costs and Section 24

Mortgage interest is no longer deductible as an expense for individual landlords holding residential property in their own name. Since April 2020, under the Section 24 rules introduced by the Finance Act 2015, individual landlords receive a basic-rate tax credit (currently 20%) on qualifying finance costs rather than a full deduction. This means that mortgage interest no longer reduces taxable rental profit, it generates a credit applied after the tax calculation. Landlords who pay income tax at the higher or additional rate are directly affected, as the restriction effectively increases their tax liability compared to the pre-2020 position.

Landlords using August consistently tell us that Section 24 is the single most misunderstood aspect of the deductible expenses framework. The full treatment of mortgage interest relief, including how the tax credit is calculated, is covered in the August entry on mortgage interest relief.

How deductible expenses are claimed

Deductible expenses are reported on the UK Property pages (SA105) of the self-assessment tax return, alongside the rental income they relate to. HMRC provides separate boxes for the main expense categories. Finance costs are entered in a separate section and generate the 20% tax credit rather than being deducted from profit. Records of every deductible expense, including invoices, receipts, bank statements, must be kept for at least five years after the 31 January filing deadline for the relevant tax year.

Tracking deductible expenses accurately is one of the core functions of landlord accounting, and one of the areas where errors are most likely to affect your tax return. The practical way to stay on top of expenditure throughout the year is to categorise each cost as it arises rather than reconstructing records at year end, which is also what Making Tax Digital will require for landlords with gross property income above £50,000 from April 2026.

For a full breakdown of each expense category, including the rules on repairs versus improvements, HMO licence fees, and replacement domestic items relief, see the August guide to allowable expenses for landlords.

Frequently asked questions

Are deductible expenses and allowable expenses the same thing?

Yes, for most purposes. Both terms refer to the costs a landlord can subtract from rental income to reduce taxable profit. HMRC uses "deductible expenses" in some formal scheme documentation and "allowable expenses" in general guidance on rental income. In practice, the test is identical: the cost must be incurred wholly and exclusively for the rental business.

Can I deduct mortgage interest from my rental income?

No, not directly. Since April 2020, individual landlords cannot deduct mortgage interest as an expense. Instead, you receive a basic-rate tax credit (20%) on qualifying finance costs, applied after your income tax is calculated. This means your taxable rental profit is calculated before any mortgage interest deduction, which increases the tax bill for higher-rate taxpayers. Companies holding property can still deduct mortgage interest as a business expense.

What expenses cannot be deducted from rental income?

Capital expenditure (improvements, extensions, conversions), the original purchase price of the property, personal costs unrelated to the letting business, mortgage capital repayments, and fines or penalties. The costs that form part of acquiring the property, including stamp duty, legal fees on purchase, cannot be set against rental income, though they may be relevant to a capital gains tax calculation on disposal.

Do I need receipts for every deductible expense?

You do not have to submit receipts with your self-assessment return, but HMRC can request evidence at any time. You are required to keep records for at least five years after the filing deadline for the relevant tax year. Digital records, including stored invoices, bank statements, and photos of receipts, are easier to produce on request and are the format required under Making Tax Digital.

This entry is intended for general informational purposes and does not constitute tax advice. The rules governing deductible expenses reflect UK tax law as of 1 May 2026. If your circumstances are complex, for example multiple properties, overseas income, property held in partnership or through a company, then consult a qualified tax adviser.