Section 24 Tax Impact Calculator
Calculate how Section 24 mortgage interest restrictions affect your rental profits.
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What is Section 24?
The Section 24 Calculator shows how the UK's mortgage interest tax relief restrictions affect landlord profits. Phased in from April 2017 to April 2020, Section 24 of the Finance (No. 2) Act 2015 fundamentally changed how rental income is taxed for individual landlords. Before Section 24, landlords could deduct mortgage interest as an expense before calculating tax. Now, you're taxed on rental profit without interest deduction, then receive a 20% tax credit. For higher-rate taxpayers, this significantly increases the effective tax rate on rental income - in some cases creating a tax liability even when actual profit is negative.
How do I calculate section 24?
This calculator compares the old and new tax systems: **Old System (Pre-Section 24)** - Taxable Profit = Rental Income - Mortgage Interest - Other Expenses - Tax Due = Taxable Profit × Marginal Tax Rate - Higher-rate taxpayers paid 40% on profit after interest deduction **New System (Post-Section 24)** - Taxable Profit = Rental Income - Other Expenses (interest NOT deductible) - Gross Tax = Taxable Profit × Marginal Tax Rate - Tax Credit = Mortgage Interest × 20% - Final Tax Due = Gross Tax - Tax Credit **Additional Tax Impact** Additional Tax = New System Tax - Old System Tax **Effective Tax Rate** Effective Rate = (Final Tax Due ÷ True Profit) × 100 Where True Profit = Rental Income - Interest - Expenses For higher-rate taxpayers, the effective rate can exceed 100% when interest costs are high relative to profit.
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Frequently Asked Questions
Why does Section 24 affect higher-rate taxpayers more?
Under the old system, a 40% taxpayer deducted interest before tax, saving 40p per £1 of interest. Now, they pay 40% tax on profit before interest deduction, then get only 20p back per £1 of interest. The 20p difference (per £1 of interest) is the additional tax burden. Basic-rate taxpayers saving 20% and getting 20% back see no change.
Can Section 24 make me pay tax on a loss?
Yes, in extreme cases. If your rental income minus expenses is positive, but your true profit (after interest) is negative, you'll still pay tax on the "paper profit" minus a 20% credit. This can create a tax bill even when you're making a cash loss. This typically happens with high LTV mortgages at high interest rates.
Should I transfer properties to a limited company?
It depends on many factors: current LTV, interest rates, your tax band, future plans, CGT liability on transfer, and SDLT costs. Companies pay corporation tax (25%) but Section 24 doesn't apply. However, transferring existing properties triggers CGT and SDLT. For new purchases, company ownership is often more tax-efficient. Seek specialist tax advice.
Does Section 24 apply to HMOs and holiday lets?
It applies to HMOs let on ASTs. However, Furnished Holiday Lets (FHLs) are currently exempt - they're treated as trading income with full interest deductibility. Note: the government has announced FHL tax advantages will be removed from April 2025, bringing them in line with standard BTL.
How can I reduce my Section 24 tax burden?
Options include: incorporating (for new purchases), paying down mortgages, remortgaging to lower rates, transferring to basic-rate taxpayer spouse, selling high-LTV properties, increasing rents, and offsetting losses from loss-making properties. Each has implications - consult a property tax specialist.
Important Disclaimer
Tax rules are complex and individual circumstances vary. This calculator provides estimates for illustration. Section 24 interacts with other tax rules including personal allowance, child benefit, pension contributions, and student loan thresholds. Always consult a qualified accountant or tax advisor for personal advice.
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