Section 24 mortgage interest tax calculator (UK, 2026/27)

See how the 20% finance-cost tax reducer works on your rental profit.

Estimate only, not tax advice. Rough 2026/27 figures for individual UK residential landlords using England, Wales and Northern Ireland rates (not Scotland, not companies). It doesn't submit anything to HMRC. Check with HMRC or a qualified accountant.

Track every property, the SA105 boxes, MTD quarters and the reducer automatically with the UK Landlord Property Tracker (£12).

How it works: mortgage interest isn't deducted from rental profit. Instead you get a tax reduction of 20% of the lowest of finance costs, property profit and adjusted total income above the personal allowance. Any excess carries forward (gov.uk). Income tax bands: gov.uk.

Rates checked on 15 October 2026 against official sources: gov.uk income tax rates · Section 24 relief · property allowance · MTD quarterly updates · 2027/28 property rates (Finance Act 2026 s.7).

General information only, not tax, legal or financial advice. Our liability is capped at the price paid, as far as the law allows. Your statutory rights are not affected. See the terms of sale. · All Kept Sheets