Section 24 calculator
Higher-rate landlords can no longer deduct mortgage interest from rental income, only a 20% tax credit applies. For leveraged portfolios, this often pushes effective tax rates above 50%.
This calculator shows your actual tax position under Section 24 and compares it with holding the same portfolio through a limited company (sometimes called a Special Purpose Vehicle, or SPV). It covers both scenarios: extracting the profits and leaving them in the company.
Your Portfolio
What this changes
Total rent received before any deductions. Drives both routes, personal route adds it to your taxable income, SPV route routes it through the company at 19% Corporation Tax (after expenses).
What this changes
Personal route: Section 24 (since 2017) only allows a 20% basic-rate tax credit on this figure, it is no longer deducted from rental profit, so a higher-rate landlord effectively pays 40% on a slice that economically isn't profit. SPV route: deducted in full at 19-25% Corporation Tax.
What this changes
Letting agent fees, repairs, insurance, ground rent, service charge, the everyday running costs (not interest, not capital improvements). Deductible against rental profit in both routes pound-for-pound.
What this changes
Salary, dividends, pension, everything else in your tax return. Pushes rental profit into a higher tax band on the personal route. The Section 24 cost is roughly zero for basic-rate-only landlords and grows sharply once total income tips over £50,270.
What this changes
Joint legal ownership is taxed 50/50 by default. If income is uneven between spouses, a Form 17 declaration plus a beneficial-ownership document can shift the split (e.g. 25/75) to keep more of the profit in the basic-rate band.
Section 24 cost
Rates current for tax year 2026/27
These calculators are diagnostic tools intended to give you an initial estimate. They are not a substitute for personalised advice on your specific circumstances. Figures depend on the inputs you provide and on tax rules that change over time. Speak to us before acting on any result.
A CIMA Chartered Management Accountant will review your details and send you a tailored breakdown.
Ongoing-tax estimate only. Does not include SDLT on transfer, CGT on disposal to SPV, or existing mortgage refinancing costs.