UK Property Income Tax Calculator 2026 (2025/26 tax year)

Reviewed by Mustafa Bilgic
UK Calculator Editor · Updated May 2026

Multi-property landlords are a single 'rental business' for tax

HMRC treats every UK residential let you own as a single rental business. Profits and losses pool: a loss-making student HMO can offset profit on a strong city-centre flat. Mortgage interest across all properties combines for the Section 24 credit cap.

The exception is foreign property — that is a separate business reported on SA106 with its own profit/loss accounting and no cross-relief with UK lets. Furnished Holiday Lets (FHLs) were also a separate business under the old regime; from April 2025 the FHL category is abolished and these properties merge back into the general residential rental business.

Loss carry-forward in 2025/26

If your portfolio makes a loss (rare but possible during refurbishment), the loss carries forward indefinitely. It can only be set against future UK rental profits — not against PAYE, dividends or savings income.

The calculator above lets you input a brought-forward loss from prior years; it shows how much of that loss is consumed by current-year profit and how much remains.

Two-flat portfolio breaking even

Rents £24,000, expenses £6,500, interest £14,000. Profit (S24 method) £17,500. PAYE £40,000. Tax on rental at 20%/40% mix = £4,054. Credit on £14,000 interest at 20% capped = £2,800. Net £1,254.

Three-flat higher-rate portfolio

Rents £42,000, expenses £10,000, interest £18,000. Profit £32,000. PAYE £55,000. Tax at 40% = £12,800. Credit at 20% × £18,000 = £3,600. Net £9,200.

Loss year used against later profit

2024/25 portfolio loss of £3,200 carried forward. 2025/26 profit £8,500. Loss reduces profit to £5,300. Tax saved at 40% marginal rate ≈ £1,280.

Common mistakes to avoid

• Treating each property's profit and loss separately on the SA105 — HMRC pools them.
• Setting rental losses against PAYE income — not allowed for residential lets.
• Forgetting to track interest by property when one is later sold; it affects the CGT base too.
• Mixing UK and foreign property income on the same form (use SA105 for UK, SA106 for foreign).
• Using the £1,000 property allowance and full expenses simultaneously.

When to use this calculator

Best used at year-end to aggregate the position before submitting Self Assessment, or before deciding to add or sell a property. Multi-property landlords should re-run after any refinance.

How this differs in Scotland, Wales and Northern Ireland

Aggregation, S24 and the property allowance are UK-wide. Scottish residents pay tax on the aggregated profit at Scottish bands. The aggregation does not cross UK and Scottish residence boundaries — your country of residence at year-end determines the rates.

When this calculator is and isn't the right tool

The UK Property Income Tax Calculator 2026 (2025/26 tax year) 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

• Property Income Tax Calculator 2025/26 — 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.
• 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 — 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 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.
• Property Flipping Tax — 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.