UK Tax · HMRC 2026

Section 24 Explained

The mortgage interest restriction that changed UK landlord tax — how it works, who it hurts, and whether a limited company actually fixes it.

Personal landlordsCapped basic-rate reductionFull tax position mattersLtd Co comparison

What is Section 24?

Section 24 of the Finance (No. 2) Act 2015 restricts deductions for finance costs of individual residential landlords. From April 2020 — after a four-year phase-in — qualifying finance costs are not deducted when calculating property profit. A basic-rate tax reduction may then apply, subject to statutory caps.

The result: finance costs no longer reduce the property profit used in the income-tax calculation. A basic-rate reduction may then apply, subject to statutory limits including finance costs, property-business profits and adjusted total income. Higher-rate tax can therefore arise on profit measured before mortgage interest.

Before vs after — the mechanics

StepPre-2017 (old rules)Post-2020 (Section 24)
Rental income£18,000£18,000
Mortgage interest−£10,000 (deducted)Not deducted
Taxable profit£8,000£18,000
Tax @ 40%£3,200£7,200
20% credit on interest−£2,000
Net tax bill£3,200£5,200

In this deliberately simplified example, the post-restriction figure is £2,000 higher. A real return also depends on other income, non-finance expenses, allowances, losses and the three tax-reduction caps.

Who does it hit hardest?

The restriction applies to qualifying finance costs of individual residential landlords. Companies are outside this Income Tax rule and may deduct qualifying finance costs when calculating company profit. The following isolates the rate effect and is not a full tax computation:

Annual extra tax cost — £10,000 mortgage interest
Basic rate (20%) taxpayer£0 extra
Higher rate (40%) taxpayer£2,000 extra / year
Additional rate (45%) taxpayer£2,500 extra / year

Basic-rate taxpayers may see the 20% reduction broadly match their rate, but that is not guaranteed because the reduction is capped and unused finance costs may need to be carried forward. Property profit before finance costs can also affect tax bands and the Personal Allowance.

Personal landlord vs Ltd Co

Personal ownership

  • Section 24 applies — capped basic-rate reduction
  • Income taxed at 20%, 40% or 45%
  • No acquisition SDLT merely for continuing to hold
  • Simpler admin, no Corp Tax return
  • CGT on sale: 18% / 24% (residential)
  • Property losses generally carry forward against future profits of the same property business

Limited company

  • Qualifying interest generally deductible for Corporation Tax
  • Corporation Tax: 19% small-profits rate, 25% main rate, marginal relief between
  • Transfer-in SDLT is transaction-specific
  • Annual accounts + CT600 required
  • CGT on sale: Corp Tax rate, not CGT
  • Profits extracted via salary/dividend

The incorporation trap

Moving existing properties into a limited company is a disposal for tax purposes and connected-party market-value rules may apply. CGT, SDLT, refinancing and professional costs depend on ownership, partnership status, consideration, debt and any reliefs; they must be established for the actual transaction.

Incorporation Relief under TCGA 1992 s162 has detailed business, whole-business, asset-transfer and consideration conditions. Property portfolios require fact-specific advice; property count alone is not a test.

Transaction-specific incorporation estimate
Capital gain and available reliefConfirm
SDLT consideration, market-value and partnership rulesConfirm
Refinance, valuation, legal and tax-advice costsQuote
Entered one-off totalModel in calculator

What should a company comparison include?

Model the same property and financing under both structures, including applicable purchase tax, mortgage rate and fees, Corporation Tax across the relevant profit range, accounting, salary or dividends, retained profit, exit tax and estate-planning objectives. Buying directly in a company avoids a later transfer of that property, but does not avoid the original acquisition costs.

Key point

Section 24 can materially change taxable property profit, but it does not determine the correct ownership structure by itself. Compare complete personal and company tax positions and obtain specialist advice before transferring property or changing finance.

Frequently asked questions

Does Section 24 apply to furnished holiday lets?
FHL properties were previously exempt, but the FHL regime was abolished from April 2025. Since then, former FHL properties are treated as standard residential lettings and fall fully under Section 24 rules.
Can I claim mortgage interest through a limited company?
A company is outside this specific Income Tax restriction and can generally deduct qualifying interest when computing taxable profit. Corporation Tax, finance terms, accounting and tax on salary or dividends still affect the comparison.
Does Section 24 affect my Personal Allowance?
It can. Residential finance costs are not deducted when calculating an individual landlord's property profit, so adjusted net income can be higher than under a full interest deduction. Personal Allowance tapering and other income must be calculated from the complete tax position.
What if I make a loss after mortgage interest?
Negative cashflow after finance costs is not necessarily a property-business tax loss, because restricted residential finance costs are excluded from the profit calculation. Allowable non-finance losses and unused finance costs have different carry-forward rules; keep them separate and confirm the tax return treatment.
Is there any relief for basic-rate taxpayers?
The reduction uses the basic rate, but it is capped by statutory measures and can be limited or carried forward. Property profit before restricted finance costs can also change tax bands and allowances, so a basic-rate taxpayer should not assume the result is automatically neutral.