Property Income Tax Calculator UK 2025/26

Reviewed by Mustafa Bilgic
UK Calculator Editor · Updated May 2026

Property income tax: the four-step HMRC calculation

Step 1: compute rental profit (gross rents minus allowable expenses, but not mortgage interest). Step 2: add this profit to your other UK taxable income to find the marginal rate slice. Step 3: apply income tax at that rate on the rental profit. Step 4: subtract a 20% basic-rate tax reducer on mortgage interest (Section 24).

Allowable expenses include letting agent fees, repairs (not improvements), insurance, ground rent, service charge, council tax during void periods, professional fees, accountancy, and legal fees on lets of less than 50 years.

The £1,000 property allowance versus claiming expenses

If your rental profit is below £1,000 you do not need to declare it at all. Above £1,000 you can choose either to claim the £1,000 allowance (no expenses) or to deduct your actual expenses. The choice is made on the SA105 each year and can switch year to year.

Sample scenario: rent £4,000, expenses £700, interest £900. Claiming actual expenses gives a profit of £3,300 with a £180 S24 credit. Claiming the allowance gives a profit of £3,000 with no credit. The allowance route saves £60 net for a basic-rate landlord — usually only worthwhile if expenses are below £1,000.

Single basic-rate landlord

Rent £12,000, expenses £2,500, interest £3,500, PAYE £28,000. Profit £9,500. Total £37,500 (basic rate). Tax: £9,500 × 20% = £1,900. Credit: £700 (20% of £3,500). Net rental tax: £1,200.

Higher-rate professional with single BTL

Rent £15,000, expenses £4,000, interest £5,000, PAYE £50,000. Profit £11,000. Total £61,000 (higher rate). Tax: £11,000 × 40% = £4,400. Credit: £1,000. Net: £3,400.

Property allowance only

Spare-room let in own home, rent £900/year. Below £1,000 — no return needed (Rent-a-Room scheme allows up to £7,500/year, even better for in-home lets). For an external let of £900: zero tax also.

Common mistakes to avoid

• Confusing the £1,000 property allowance with the £7,500 Rent-a-Room scheme — different rules.
• Deducting capital costs (new kitchen, extension) as 'repairs' — these are improvements, deductible only against CGT.
• Claiming both expenses and the property allowance in the same tax year.
• Forgetting to apportion expenses if the property was let for only part of the year.
• Missing the £1,000 trading allowance on rent-a-room from a B&B-style operation.

When to use this calculator

Use at year-end to project your January tax bill, before considering whether to enter or exit the BTL market, and when comparing claiming actual expenses versus the £1,000 allowance.

How this differs in Scotland, Wales and Northern Ireland

Property income tax bands differ for Scottish residents (19% starter, 20% basic, 21% intermediate, 42% higher, 45% advanced, 48% top rate). Welsh and NI residents use the same bands as England. The £1,000 property allowance and Section 24 are UK-wide.

When this calculator is and isn't the right tool

The Property Income Tax Calculator UK 2025/26 above is built for the most common UK 2025/26 scenarios in this tax area. It will be the right tool when your situation maps cleanly onto the inputs — single property or simple aggregation, standard HMRC rates and bands, and individual taxpayer (rather than complex trust or partnership structures). It is informational and does not replace tailored advice from a chartered tax adviser, especially for transactions above £500,000, cross-border situations, or where reliefs interact with each other. For year-end filings, always reconcile with HMRC's own free calculators on gov.uk before pressing submit on Self Assessment.

Closely related calculators

• UK Property Income Tax Calculator 2026 — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• UK Landlord Tax Calculator — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Rental Income Tax Calculator — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• £1,000 Property Allowance — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.
• Section 24 Mortgage Interest — useful when you need a different angle on the same UK property tax topic, especially if your situation involves multiple types of property income or disposal.

Glossary of UK property tax terms

Section 24

The 2017 rule replacing full mortgage interest deduction with a 20% tax credit for individual residential landlords.

SA105

The Self Assessment supplementary form for UK property income.

Box 44

The SA105 box for residential property finance costs (mortgage interest).

Property allowance

£1,000 tax-free band for individual property income, claimable instead of expenses.

Rent-a-Room scheme

Separate £7,500 allowance for letting a furnished room in your main home.

Tax planning checklist

1. Confirm the figures input above match your actual position — purchase contract, mortgage offer or completion statement.
2. Cross-check the year (2025/26) — figures change every April. The tax year 2026/27 starts 6 April 2026.
3. Use HMRC's official calculator at gov.uk for the final filing figure; this calculator is informational.
4. Keep records for at least 6 years — HMRC's normal enquiry window. 21 years for fraud investigations.
5. Discuss any unusual transaction (joint purchase, gift, divorce settlement, trust) with a qualified tax adviser.
6. Submit your return online via Government Gateway — paper deadlines are earlier and penalties harsher.