Free tool · Section 24
Rental Profit & Section 24 Calculator
Enter your rent and allowable expenses to get your taxable rental profit, with mortgage interest handled the way HMRC treats it: as a tax credit, not a deduction. Switch between 2026/27 and 2027/28 to see the April 2027 change. Your figures save in your browser, nothing is sent to a server.
Rental profit and Section 24, answered
Why isn’t my mortgage interest deducted from my rental profit?
Under Section 24, individual landlords cannot deduct residential mortgage interest as an expense. Instead you get a tax credit at the basic rate on the interest you paid. Your taxable profit stays higher, which is why higher-rate taxpayers often pay more than they expect.
What changes from April 2027?
From 6 April 2027 property income has its own tax rates: 22% basic, 42% higher and 47% additional. The Section 24 credit follows the property basic rate, so it rises from 20% to 22% of your interest. If you pay Scottish or Welsh income tax, check how the new property rates apply to you.
Does Section 24 apply if I own through a limited company?
No. A limited company deducts its mortgage interest as an ordinary business expense and pays Corporation Tax on the profit that is left. This calculator is for property you own personally.
What counts as an allowable expense?
Running costs of the let: letting agent and management fees, repairs and maintenance (not improvements), landlord insurance, accountancy, ground rent and service charges, and services you pay for such as cleaning or gardening. Buying the property or improving it is capital spending and is not deducted here.
Is the result my tax bill?
No. It is your taxable rental profit and the value of your Section 24 credit. Your bill depends on your other income, tax band and personal allowance, and the credit can be capped when your profit or total income is low. Take the figures to your accountant or your self-assessment return.
This tool is guidance, not legal advice. The rules it applies were last reviewed on 6 October 2026 against: gov.uk — paying tax on rental income · gov.uk — restricting finance cost relief for individual landlords · gov.uk — changes to tax rates for property, savings and dividend income. If your situation is unusual or contested, take advice before serving anything.