SA105 is the UK property page of the Self Assessment tax return. You fill it in if your property income, including foreign property, is over £1,000 and you get rent from UK land or property, income from letting furnished rooms in your home, lease premiums or a reverse premium. For 2025 to 2026, the furnished holiday lettings regime has gone, so holiday lets are reported like any other property income.
The pages cover the tax year 6 April 2025 to 5 April 2026. Everything below is from HMRC's 2026 UK property notes and form, as of October 2026.
Do you need SA105?
| Your situation | What the notes say |
|---|---|
| All property income, including foreign, is £1,000 or less | It's exempt and doesn't need to go on a return |
| Property income over £1,000 | Complete the UK property pages |
| You let furnished rooms in your own home | Use the pages, and consider Rent a Room relief |
| Your letting is a trade, such as a guest house or bed and breakfast | Use the Self-employment pages instead |
| You let property overseas | Use the Foreign pages |
| Your property income comes through a partnership | Use the Partnership pages |
If you don't need a return, the notes say you must tell HMRC by 31 January 2027 to avoid penalties.
The property allowance or real expenses: pick one
If your property income is over £1,000, you can either claim the property income allowance in box 20.1 or work out your profit by deducting allowable expenses. You can't do both. Whether you have one property business or several, the allowance can't exceed £1,000 in total, and you can't claim it if any of your property income is from a connected party, as of October 2026.
Rent a Room relief
If you let furnished accommodation in your own home and your rents are £7,500 or less, or £3,750 if let jointly, you can claim Rent a Room relief. If you put Rent a Room income in box 20, put the exempt amount in box 37. You can't claim the property income allowance on the same Rent a Room income.
Cash basis or traditional accounting
Box 20.2 asks whether you're using traditional accounting rather than cash basis. Cash basis is the simpler way of working out profit, and you can only use it if your total income from UK property is up to £150,000. If your total property income before expenses is below £90,000, you can just add up your expenses and put the total in box 29, excluding residential property finance costs.
The part landlords miss: mortgage interest
You can't deduct the costs of getting a loan to buy a residential property you let, or the interest on it, as an expense. Instead, those costs go in box 44, and they're used to calculate a reduction in your Income Tax. Unused amounts from earlier years go in box 45, and any balance still unrelieved can be carried forward to future years of the same property business. Putting mortgage interest in the expenses boxes is the most common SA105 error, and it overstates the relief.
Non-residential property finance costs are different: they go in box 26 as an expense.
Key boxes
| Box | What goes in it |
|---|---|
| 20 | Total rents and other income from property |
| 20.1 | Property income allowance, if you claim it |
| 20.2 | Traditional accounting rather than cash basis |
| 26 | Non-residential property finance costs |
| 27 | Legal, management and other professional fees |
| 29 | Total expenses, if your income is below the threshold for a single figure |
| 37 | Rent a Room exempt amount |
| 39 | Losses brought forward used against this year's profits |
| 44 | Residential property finance costs |
| 45 | Unused residential property finance costs brought forward |
Jointly owned property
If you own and let property jointly, put X in box 3 and enter only your share of the income and expenses. If you live with your spouse, HMRC taxes your shares equally. If your real shares are different and you want them taxed that way, you fill in form 17, Declaration of beneficial interests in joint property and income. If someone else prepares the accounts and simply tells you your share of the profit or loss, put the income in box 20 or the loss in box 29, and give the name and address of the person who prepares them.
Non-resident landlords
If you're a non-resident landlord and want to claim back tax paid under the non-resident landlord scheme, you fill in box 1, box 2 if it applies, and box 21. The rest of the pages work the same way as for a UK resident landlord.
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Losses
Put unused losses from earlier years in box 39, up to the amount in box 38, using box 43 of last year's pages. You can only set a property loss against your total income if it's from agricultural expenses or capital allowances. Everything else carries forward against future property profits.
Filling it in, step by step
- Check whether all your property income is £1,000 or less. If so, you may not need the pages.
- Decide between the property allowance and real expenses.
- Decide on cash basis or traditional accounting, within the £150,000 limit.
- Enter income in box 20, expenses in the expense boxes or box 29, and mortgage interest only in box 44.
- Bring forward losses and unused finance costs from last year.
For the bigger picture on rental properties as income, and the Self Assessment deadline, those guides help.
The verdict
SA105 is simple once you separate three things: the £1,000 allowance versus real expenses, Rent a Room for rooms in your own home, and mortgage interest in box 44 only. Get those right and most landlords' pages take minutes. If you ran a holiday let, it now sits in the same pages as everything else.
Frequently asked questions
What is SA105?
It's the UK property page of the Self Assessment return, used to report rents and other income from UK land and property.
Do I need to fill in SA105 if my rental income is small?
All property income up to £1,000, including foreign property, is exempt and doesn't need to be reported. Over £1,000, complete the UK property pages.
Where does mortgage interest go on SA105?
Residential property finance costs go in box 44, where they're used to calculate a reduction in your Income Tax. They aren't deducted as an expense.
What is the Rent a Room limit on SA105?
£7,500, or £3,750 if let jointly, as of October 2026. Put the exempt amount in box 37.
What happened to furnished holiday lettings on SA105?
The FHL regime was abolished from 5 April 2025. Income and gains from furnished holiday lets are now treated like all other property income.
