Landlord Tax / Lesson 6 of 9
Reporting rental profit on your return
You made £600 profit on a flat. Does that need a tax return at all?
The short answer
- ✓ A return is required at £2,500 of profit, or £10,000 of income before expenses
- ✓ Finance costs go in their own box, not with the other expenses
- ✓ Property losses carry forward against future property profits only
- ✓ Keep purchase and improvement paperwork indefinitely for the eventual CGT calculation
When a return is required
| Property income | What you must do |
|---|---|
| Under £1,000 | Covered by the property allowance, generally nothing to report |
| £1,000 to £2,500 profit | Contact HMRC, it may be collectable another way |
| £2,500 or more profit | Self Assessment return required |
| £10,000 or more income before expenses | Self Assessment return required |
Note the last row uses income rather than profit. A landlord with £11,000 of rent and £9,000 of costs has only £2,000 of profit but is still inside Self Assessment on the income test.
What the property pages ask for
Number of properties let
Total rents and other income
Expenses, by category:
rent, rates, insurance, ground rent
repairs and maintenance
loan interest and other finance costs (entered separately, for the credit)
legal, management and professional fees
costs of services provided
other allowable expenses
Adjustments: private use, balancing charges
Losses brought forwardFinance costs go in their own box precisely because they are not deducted from profit. Putting mortgage interest in with the other expenses is the most common mistake on these pages, and it produces a return that is wrong in your favour, which is the worst kind.
Losses
A property loss is carried forward automatically against future profits of the same property business. It cannot generally be set against your other income, such as employment. Because all your UK properties pool into one business, a loss on one is already absorbing profit from another before it ever becomes a carried-forward loss.
The bit HMRC does not spell out
Record the loss even in a year when you owe nothing. Landlords frequently skip the property pages entirely in a loss-making year on the reasoning that there is no tax to pay, and by doing so they lose the loss. A carried-forward loss is only carried forward if it was reported, and the year it would have sheltered arrives two or three years later when nobody remembers.
Keeping the records
The same five-year rule applies as for any Self Assessment record, and property has an extra dimension: keep the purchase paperwork and every improvement receipt indefinitely. Those are not needed for your annual rental profit, but they are exactly what you will need to calculate Capital Gains Tax when you sell, which could be twenty years from now.
Common mistakes
- Putting mortgage interest in with other expenses. It has its own box.
- Not reporting a loss year. An unreported loss cannot be carried forward.
- Testing the £10,000 threshold against profit. That one is on income.
- Discarding purchase and improvement paperwork. You need it decades later for CGT.
Try it on your own numbers
This is the same calculator as the full tool page, using 2026/27 rates.
Your rental portfolio
Add each property below. Enter the mortgage interest only (not capital repayment) so we can apply the Section 24 rules correctly.
Total income
Taxable profit
Estimated tax
After-tax income
Section 24: mortgage interest is not deducted from profit; instead it gives a 20% tax credit (capped at your profit). Total mortgage interest entered: , giving a credit of .
| Property | Income | Expenses | Interest | Profit | Tax | |
|---|---|---|---|---|---|---|
No properties added yet. Add one above - everything saves privately in your browser so you can return any time.
Key takeaways
- ✓ A return is required at £2,500 of profit, or £10,000 of income before expenses
- ✓ Finance costs go in their own box, not with the other expenses
- ✓ Property losses carry forward against future property profits only
- ✓ Keep purchase and improvement paperwork indefinitely for the eventual CGT calculation
Check you have got it
3 quick questions. No score is kept, and you can change your mind.
1. You receive £11,000 of rent with £9,000 of costs. Do you need to file?
2. Where does mortgage interest go on the property pages?
3. You made a property loss this year and owe nothing. Should you still report it?
Sources
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