The phrase rental income tax calculator hides the part landlords actually get wrong. The arithmetic of "rent minus costs, taxed at your band" is simple. The traps are which costs count, the Section 24 mortgage-interest add-back that no spreadsheet does for you automatically, and how the profit stacks on your other income. Get those three right and the rest is addition.
This guide walks the calculation in the order HMRC expects it, with a worked example, a tax-band table, the limited-company comparison landlords keep asking about, and what changes when the new property income rates take effect on 6 April 2027.
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How to work out your rental income tax, step by step
Whatever rental income tax calculator you use, it should follow this sequence. Skip a step and the figure is wrong, usually in HMRC's favour.
1. Total your gross rental income
Add up everything received for the tax year (6 April to 5 April): rent, service charges you collect from tenants, ground rent you receive, and any lease premiums. Most landlords use the cash basis by default (income when received, expenses when paid) if gross receipts are 150,000 pounds or less. Above that, or by election, you use the accruals basis and count rent on the date it falls due.
2. Deduct allowable revenue expenses
Subtract costs incurred wholly and exclusively for the letting. The common allowable items:
- Letting agent and property management fees
- Landlord insurance (buildings, contents, rent guarantee, legal expenses)
- Repairs and maintenance that restore, rather than improve (a like-for-like boiler, not a loft conversion)
- Ground rent and service charges you pay
- Council tax and utilities during void periods or where rent is inclusive
- Accountancy and professional fees for the let
- Advertising for tenants, referencing, and inventory costs
- Gas, electrical and EPC safety certificates
- Direct costs of travelling to manage or inspect the property
The full list of landlord tax deductions goes deeper, including the replacement-of-domestic-items relief that replaced the old wear-and-tear allowance.
3. Keep finance costs out of the deduction
This is the step a basic calculator misses. Mortgage interest, loan interest and arrangement fees on a residential let held personally are not deducted as expenses. They are parked and turned into a tax credit at the end. Deduct them here and you understate your taxable profit, which means you understate your tax band, which compounds the error.
4. Stack the profit on your other income
Your rental profit is added on top of salary, pension and other taxable income. That combined total decides which band the profit falls into, and the profit is taxed at your marginal rate, not a flat rate. This is why two landlords with identical properties can pay very different tax.
5. Calculate the tax, then deduct the Section 24 credit
Work out income tax on the full profit (before any mortgage interest), then reduce the bill by a basic-rate credit on your finance costs. For 2026/27 that credit is 20%. The credit is the lower of (a) your finance costs, (b) your property profits, and (c) your income above the personal allowance, so a loss-making or low-profit year can restrict it, with the unused portion carried forward.
The tax bands your rental profit is taxed at (2026/27)
For 2026/27, rental profit is taxed at the standard UK income tax rates once stacked on your other income. The figures below are for England, Wales and Northern Ireland; Scottish taxpayers use Holyrood-set bands.
| Band | Taxable income (after personal allowance) | Rate on rental profit |
|---|---|---|
| Personal allowance | First 12,570 pounds | 0% |
| Basic rate | 12,571 to 50,270 pounds | 20% |
| Higher rate | 50,271 to 125,140 pounds | 40% |
| Additional rate | Over 125,140 pounds | 45% |
The personal allowance tapers away by 1 pound for every 2 pounds of income over 100,000 pounds, so a landlord whose rental profit pushes total income through that line faces an effective 60% marginal rate on the affected slice. That band-stacking effect is the single biggest driver of an unexpected bill.
A worked Section 24 example
Take Priya, a higher-rate landlord. She has a 60,000 pound salary and one buy-to-let: 18,000 pounds rent, 4,000 pounds of allowable expenses, and 7,000 pounds of mortgage interest.
| Step | Figure |
|---|---|
| Gross rent | 18,000 pounds |
| Less allowable expenses | (4,000 pounds) |
| Taxable rental profit (interest NOT deducted) | 14,000 pounds |
| Tax at 40% (her marginal rate) | 5,600 pounds |
| Less Section 24 credit (20% of 7,000 pounds interest) | (1,400 pounds) |
| Tax actually due on the rental profit | 4,200 pounds |
Under the pre-2017 rules she would have deducted the 7,000 pounds interest first, leaving 7,000 pounds profit taxed at 40%, a 2,800 pound bill. Section 24 costs her 1,400 pounds more on this property alone, because her interest is relieved at 20% while her profit is taxed at 40%. A basic-rate landlord with the same figures is broadly neutral, since the 20% credit roughly matches the 20% rate. The deeper mechanics, including the carry-forward when the credit is restricted, are in our guide on claiming mortgage interest under Section 24.
What changes on 6 April 2027
Finance Act 2026 received Royal Assent on 18 March 2026 and introduced separate property income tax rates from 6 April 2027: 22% basic, 42% higher and 47% additional. These apply to property income in England, Wales and Northern Ireland; only Scotland is carved out, with Scottish taxpayers continuing on Holyrood-set rates. Read the detail in our breakdown of the 2027 property income tax rates for landlords.
The point most commentary gets wrong: the Section 24 finance-cost credit rises in step from 20% to 22% for 2027/28. So no new basic-rate wedge opens. A basic-rate landlord pays 22% on property profit and gets a 22% credit on interest, still broadly neutral. A higher-rate landlord sees relief improve from 20% to 22%, a 2 percentage point gain, but it remains well below their 42% headline rate, so the finance-cost wedge is essentially unchanged.
| 2026/27 | 2027/28 (England, Wales, NI) | |
|---|---|---|
| Basic rate on property profit | 20% | 22% |
| Higher rate | 40% | 42% |
| Additional rate | 45% | 47% |
| Section 24 finance-cost credit | 20% | 22% |
| Higher-rate finance wedge | 20pp | 20pp |
Calculating tax across multiple properties
All your UK residential lets are a single property business. You do not file a separate calculation per property, you pool them: combine the rents, pool the allowable expenses, and total the finance costs for one Section 24 credit. A loss on a refurbished property offsets a profit on another in the same year, and any net loss carries forward against future rental profits.
Since 6 April 2025 the furnished holiday lettings regime has been abolished, so former FHL properties now sit inside the same residential property business with everything else, lose the old capital-allowances and interest-relief advantages, and follow the standard Section 24 treatment. If you still treat a former holiday let as a special category in your calculator, you are using a regime that no longer exists.
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Capital versus revenue: the expense trap
The line between a deductible repair and a non-deductible improvement decides whether a cost reduces this year's income tax or instead sits as base cost against a future capital gain. Replacing a tired kitchen with a similar one is a revenue repair, fully allowable now. Extending the kitchen, or upgrading from a basic fitment to a high-spec one, is capital expenditure: it gives no income-tax deduction but adds to base cost and reduces the eventual capital gains tax when you sell.
Capital allowances can still apply to plant and machinery in the common parts of a property business and to commercial or mixed-use property, but not to the residential dwelling itself. Misclassifying improvements as repairs is one of HMRC's most common enquiry triggers, so keep the invoices and the before-and-after detail.
Don't forget capital gains tax when you sell
Income tax on rent is only half the picture. When you sell a residential investment property at a gain, capital gains tax applies at 18% for basic-rate taxpayers and 24% for higher and additional-rate taxpayers, against the gain after the 3,000 pound annual exempt amount for 2026/27. A UK-resident individual must report and pay within 60 days of completion via a CGT-on-property account. The current rates and bands are set out in our guide to CGT rates on property for 2026/27.
Section 24 versus a limited company
The structure question follows naturally from the Section 24 wedge: a company deducts mortgage interest in full and pays corporation tax on the profit, rather than carrying a 20% credit against a 40% or 45% personal rate. That advantage is real but partial, because extracting the money as dividends is taxed again, and moving existing property into a company can trigger capital gains tax and stamp duty.
| Feature | Personal ownership | Limited company |
|---|---|---|
| Mortgage interest relief | 20% credit (22% from 2027/28) | Full deduction against profit |
| Tax on profit | 20% / 40% / 45% marginal | Corporation tax on company profit |
| Getting money out | Already personal | Dividend or salary, taxed again |
| Moving existing property in | n/a | Can trigger CGT and SDLT |
| Reporting | Self assessment plus MTD | Company accounts and CT return |
Whether incorporation pays depends on your marginal rate, how geared the portfolio is, and whether you draw the profit or reinvest it. Our buy-to-let limited company guide works the comparison through with figures. It is not a default answer, and it is rarely worth it for a single lightly-geared property.
Making Tax Digital: report quarterly, not just calculate
Making Tax Digital for Income Tax is live and changes how you report, not how the tax is worked out. The mandate phases in on gross qualifying income, not profit:
| From | Gross qualifying income threshold |
|---|---|
| 6 April 2026 | Over 50,000 pounds |
| 6 April 2027 | Over 30,000 pounds |
| 6 April 2028 | Over 20,000 pounds |
Because the test is on gross rent and trade turnover, a landlord with 52,000 pounds of rent and only 12,000 pounds of profit is still in scope from April 2026. You will keep digital records, send quarterly updates, and submit a final declaration after the year end. If you let jointly, each owner tests their share of gross income against the threshold separately. The qualifying-income test is explained in our note on the MTD ITSA qualifying income test.
Where a calculator stops and judgement starts
A rental income tax calculator earns its place for a single, straightforward let with one mortgage and one owner. It quietly produces the wrong answer once you have any of the following, and these are exactly the situations where the tax at stake is largest:
- Several properties with mixed financing and a pooled Section 24 credit
- Joint or spousal ownership, where a Form 17 election can shift the income split
- A company structure, or the question of whether to incorporate
- A sale in the year, with capital gains tax to report inside the 60-day window
- The 2027/28 rate transition to plan acquisitions and disposals around
These interactions are where a flat calculator and a specialist diverge most. If you are weighing up the year ahead, the broader picture is in our overview of landlord tax changes for 2026, and you can request a review of your own figures through the form on this page.