Scope: applies UK-wide; Scotland sets its own income tax rates and bands. 2026/27 tax year.
Losses are simple once you see that there are separate pots and that they do not mix. Most mistakes here are a loss being set against the wrong thing.
The rule
A loss from a UK property business:
- carries forward indefinitely, and
- is set against the first available future profits of the same property business.
It is automatic, not an election. You cannot choose to carry less forward to preserve an allowance — it is set against the first profits going.
What it cannot be set against
This is the part that costs people:
- Not your salary or other income. A property loss does not reduce employment income. There is no general sideways relief for an ordinary property business.
- Not a capital gain. Rental losses are income losses. They cannot reduce the gain when you sell. Capital losses set against capital gains; income losses against income. Different pots, and they never meet.
- Not carried back to an earlier year.
All your properties are one business
Every UK residential property you let as an individual is a single UK property business. Profits and losses are pooled automatically — a loss on one and a profit on another net off in the same year, with no election needed.
What is separate:
- Overseas property is a different business. Losses there cannot reduce UK property profits.
- Property held individually versus jointly can be the same business; property held through a company is entirely separate — the company's losses are the company's.
Section 24 is not a loss
Worth stating because the two get conflated. Unused finance cost relief is not a rental loss. It is unused tax reduction, carried forward separately to reduce a later year’s liability. A landlord can have no rental loss at all and still carry forward unused finance cost relief — and the two are tracked in different places on the return.
You must claim it to keep it
A loss has to be reported in the year it arises to be available later. It does not accrue silently in HMRC’s records because you had a bad year and did not mention it. Under Making Tax Digital the loss is established at the final declaration, not in a quarterly update.
When losses actually arise
Less often than landlords expect, because the biggest cash cost — mortgage interest — is no longer an expense. Since 6 April 2020 profit is calculated before interest, so a property that loses money in cash terms can still show a taxable profit. Genuine tax losses now tend to come from a major repair year, a long void, or the early years of a heavily-costed let.
Records make the claim. Check what applies to your property — five questions, no signup.
Information tool, not tax advice.