Form SA105 Landlord Tax Return
Form SA105 is the UK property page of the Self Assessment tax return. See who files it, what goes in each box for 2025/26, the £1,000 allowance, Section 24 and joint ownership.
In one sentence
Form SA105 is the HMRC Self Assessment supplementary page used by UK individual landlords to report rental income, allowable property expenses and residential finance costs.
Quick answer
- Complete SA105 if your property income before expenses is over £1,000 in the tax year
- Box 20: total rents and other property income, before expenses
- Boxes 24 to 29: property expenses. Box 20.1: the £1,000 property income allowance, instead of expenses
- Box 44: residential mortgage interest and finance costs, relieved as a 20% tax reduction
- Joint owners each report their own share on their own return
- For 2025/26 the online return is due by 31 January 2027
What is Form SA105?
Form SA105 is the "UK property" supplementary page of the Self Assessment tax return. A landlord reports rental income and property expenses on SA105, and it feeds into the main SA100 tax return. For the 2025/26 tax year (6 April 2025 to 5 April 2026) the return is due online by 31 January 2027, or on paper by 31 October 2026. Any tax is due on 31 January 2027.
If people say "property tax return", this is usually what they mean: the SA100 return plus the SA105 pages. HMRC's SA105 page on GOV.UK has the form and the notes. Most landlords now file online, where the same boxes appear as questions.
Do you need to complete Form SA105?
Complete the UK property pages if your total property income, before expenses, is over £1,000 in the tax year. Property income includes rent, ground rents, premiums on leases and income from furnished lettings.
- £1,000 or less: the property income allowance covers it. It is exempt from tax and does not need to go on the return.
- Over £1,000: complete SA105. You choose between claiming the £1,000 allowance (box 20.1) or deducting your actual expenses. You cannot do both.
- Letting a room in your own home: if rents are £7,500 or less (£3,750 if shared), Rent a Room relief may apply and you tick box 4. If this is your only letting income you do not need to complete the rest of the page.
- Joint owners: each owner reports their own share on their own return and ticks box 3.
You may still choose to complete SA105 below the £1,000 limit to record a loss and carry it forward. Furnished holiday lettings no longer have a separate regime from 6 April 2025. Their income is reported in the normal UK property boxes.
Key boxes on Form SA105 for 2025/26
These are the boxes most landlords use. The numbers come from HMRC's UK property notes for 2025/26.
| Box | What it is | What to enter |
|---|---|---|
| 3 | Jointly let property | Put 'X' if you let property jointly. Report only your share. |
| 4 | Rent a Room, rents £7,500 or less | Put 'X' if all your letting income is within the Rent a Room exemption. |
| 20 | Total rents and other income from property | Gross rent for the year, before any expenses. Include ground rents and other property income. |
| 20.1 | Property income allowance | The £1,000 allowance, if you claim it instead of expenses. |
| 20.2 | Traditional accounting | Put 'X' if you used traditional accounting instead of the cash basis. |
| 24 to 29 | Property expenses | 24 rent, rates, insurance and ground rent; 25 repairs and maintenance; 26 non-residential finance costs; 27 legal, management and professional fees; 28 services including wages; 29 other allowable expenses. |
| 36 | Replacing domestic items | The cost of replacing furniture, appliances and similar items in residential lets. |
| 38 / 41 | Adjusted profit or loss | Your taxable profit goes in box 38. A loss goes in box 41. |
| 39 | Losses brought forward used | Unused rental losses from earlier years, up to the profit in box 38. |
| 43 | Loss to carry forward | Any loss not used this year, including losses brought forward. |
| 44 | Residential property finance costs | Mortgage interest and loan costs on residential lets. These get a 20% tax reduction, not a deduction. |
| 45 | Unused finance costs brought forward | Residential finance costs that earlier years could not relieve. |
If your property income before expenses is below £90,000 you can add up your expenses and put the total in box 29. Box numbers can change from year to year, so use the notes for the year you are filing. Source: HMRC UK property notes (2025-26).
How to fill in SA105: worked example
Maya owns one residential buy-to-let in her own name. In 2025/26 she received £18,000 rent. Her costs were £600 insurance (box 24), £1,200 repairs (box 25), £1,800 agent fees (box 27) and £400 other costs (box 29). Her mortgage interest was £5,000.
| Box | Entry | Amount |
|---|---|---|
| 20 | Total rents | £18,000 |
| 24 | Insurance | £600 |
| 25 | Repairs and maintenance | £1,200 |
| 27 | Management fees | £1,800 |
| 29 | Other expenses | £400 |
| 38 | Adjusted profit (£18,000 − £4,000) | £14,000 |
| 44 | Residential finance costs | £5,000 |
The mortgage interest is not deducted in boxes 24 to 29. HMRC takes 20% of the £5,000 (£1,000) off her Income Tax bill instead. The reduction is limited to the lowest of the finance costs, her property profit and the income she has above her Personal Allowance, so the result is different for each landlord.
Property income allowance or actual expenses?
The £1,000 allowance is a flat deduction. It is worth claiming only when your real expenses are lower.
| Example | Rent | Actual expenses | Taxable profit with allowance | Taxable profit with expenses |
|---|---|---|---|---|
| Spare room let out | £3,000 | £300 | £2,000 | £2,700 |
| Small let with repairs | £3,000 | £1,800 | £2,000 | £1,200 |
In the first example the allowance is better. In the second the expenses are better. You cannot claim the allowance on income from a connected party, and you cannot claim both. Source: GOV.UK tax-free allowances.
Reporting residential mortgage interest (Section 24)
Under the residential property finance cost rules, mortgage interest and loan arrangement costs on residential lets cannot be deducted from your rent. Enter the total in box 44. Non-residential property finance costs go in box 26 as an expense.
The tax reduction is 20% of the finance costs, so higher-rate and additional-rate taxpayers get less relief than they used to. Basic-rate taxpayers are broadly unaffected. Companies are not subject to the same restriction, which is why many landlords look at an SPV. Read Section 24 explained for the full picture.
Joint ownership on Form SA105
- Each joint owner files their own SA105 and reports their own share of the income and expenses.
- Spouses and civil partners who live together are taxed on equal shares by default.
- If you actually own the property in unequal shares, you can ask for the income to be taxed in those shares by filing Form 17 (Declaration of beneficial interests), and you must hold the property in those shares.
Common mistakes on the property pages
- Entering rent net of agent fees in box 20. Put gross rent in box 20 and the fees in box 27.
- Deducting mortgage interest as an expense. It goes in box 44 for residential lets.
- Claiming the £1,000 allowance and expenses together.
- Claiming the cost of improvements as repairs. Capital costs are not allowable against rent.
- Forgetting losses from earlier years in boxes 39 and 43.
- Missing the Capital Gains Tax return when a property is sold. UK residential property sales need a return within 60 days.
Making Tax Digital and SA105
If your gross property and self-employment income was over £50,000 in 2024/25, Making Tax Digital for Income Tax applies from 6 April 2026. You keep digital records and send quarterly updates, with the same income and expense categories as Self Assessment. The threshold falls to £30,000 from April 2027 and £20,000 from April 2028. Read our MTD for landlords guide. Your 2025/26 return is still filed the normal way.
Read our guide to allowable expenses for UK landlords, see the Self Assessment deadlines or see how our landlord accounting service prepares the SA105 pages.
Need help completing your SA105 property tax pages?
Book a 30-minute call. We will confirm whether we are a fit and, if we are, tell you exactly what the next step looks like.
Book a call →Frequently asked questions
What is Form SA105?
Form SA105 is the UK property page of the Self Assessment tax return. Landlords use it to report rental income and property expenses. It feeds into the main SA100 return.
Do I need to fill in SA105 if my rental income is under £1,000?
No. Property income up to £1,000 is covered by the property income allowance. It is exempt from tax and does not need to be reported, although you can complete the property pages to record a loss.
Which SA105 box is rental income?
Total rents and other income from property go in box 20 for 2025/26. Enter the gross figure before expenses. Box 20.1 is where you claim the £1,000 property income allowance instead of deducting expenses.
Where does mortgage interest go on SA105?
For residential lets, mortgage interest and loan costs go in box 44, not in the expenses boxes. They are relieved as a tax reduction of 20% of the costs. Finance costs on non-residential property go in box 26 as an expense.
When is the SA105 deadline for 2025/26?
SA105 is filed with your Self Assessment return. For the 2025/26 tax year the online return is due by 31 January 2027, and a paper return by 31 October 2026. Tax is due on 31 January 2027.
Can I claim the £1,000 property allowance and expenses together?
No. Over £1,000 of property income, you either claim the allowance in box 20.1 or deduct your actual expenses. You cannot claim both, and you cannot use the allowance on income from a connected party.
How do joint owners complete SA105?
Each joint owner files their own SA105 with their own share of the income and expenses and ticks box 3. Spouses and civil partners who live together are taxed on equal shares unless they file Form 17 and actually own the property in unequal shares.
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