Key takeaways

  • The SA105 is the supplementary page of the tax return for UK rental income; for 2025-26 it must reach HMRC online by 31 January 2027.
  • Furnished holiday lettings no longer have their own section: the regime ended on 5 April 2025, so all UK lets go in one property business.
  • On the 2025-26 form boxes 5 to 19 are no longer in use; income and expenses go in boxes 20 to 45.
  • Total rents go in box 20, and the £1,000 property income allowance is claimed in box 20.1 instead of listing expenses.
  • Residential mortgage interest is not an expense: it goes in box 44 and gets a tax reduction at the 20% basic rate.
  • You cannot claim the property allowance in a year when the residential finance cost reducer applies, so landlords with mortgages usually claim actual expenses.
  • The Rent a Room limit is £7,500, or £3,750 if the income is shared with someone else.

The SA105 is the part of your Self Assessment return where you report income from letting UK property. For 2025-26 you put your total rents in box 20, your running costs in boxes 24 to 29 and your residential mortgage interest in box 44, then work out the taxable profit in boxes 38 to 40. The online return is due by 31 January 2027.

Who needs to fill in the SA105?

You need the UK property pages if you received rent or other income from UK land or property in the year to 5 April 2026 and it is above the reporting limits. GOV.UK says gross property income over £2,500 means registering for Self Assessment; between £1,000 and £2,500 you contact HMRC instead.

You do not need the pages if your gross property income was £1,000 or less and the property allowance covers it in full. Our guide to Self Assessment thresholds lists every trigger.

What has changed on the 2025-26 form?

The main change is that furnished holiday lettings no longer have a separate section. HMRC’s notes say the FHL regime was abolished from 5 April 2025, so former holiday lets now sit inside one UK property business with your other lets.

The form also says boxes 5 to 19 are no longer in use. Everything goes in boxes 20 to 45. If you copy last year’s figures across, check the box numbers carefully. Our page on furnished holiday let tax rules covers the wider effect of the abolition.

SA105 box by box

The table below follows the 2025-26 form published on GOV.UK’s SA105 page, last updated 6 April 2026.

BoxWhat goes in it
1 to 4Property details, including income ceased (box 2) and jointly let (box 3)
20Total rents and other income from property
20.1Property income allowance (instead of expenses)
21Tax taken off the income in box 20
22 and 23Lease premiums; reverse premiums and inducements
24 to 29Allowable expenses
30 and 31Private use adjustment; balancing charges
32 to 36Capital allowances and replacement of domestic items (box 34 not in use)
37Rent a Room exempt amount
38 to 40Adjusted profit, losses used, taxable profit
41 onwardsLosses
44 and 45Residential finance costs; unused costs brought forward

One SA105 covers your whole UK property business. You do not fill in a separate page for each property. If you let jointly, enter only your share.

Where do rent and expenses go?

Rent goes in box 20 as a gross figure, before any costs. Include other property income, such as charges for services you provide.

Expenses are split across boxes 24 to 29:

  • Box 24: rent, rates, insurance and ground rents
  • Box 25: property repairs and maintenance
  • Box 26: finance costs for non-residential (commercial) property only
  • Box 27: legal, management and other professional fees
  • Box 28: costs of services provided, including wages
  • Box 29: other allowable property expenses

If any of those costs were partly private, put the private part in box 30. Our list of landlord allowable expenses explains what counts.

Where does mortgage interest go?

Mortgage interest on a residential let goes in box 44, not in the expense boxes. GOV.UK explains that you get a tax reduction of 20% of the lowest of three amounts: your finance costs (plus any brought forward), your property profits, and your adjusted total income above the Personal Allowance.

Any unused amount carries forward to the next year through box 45. The reduction cannot create a refund. See section 24 mortgage interest relief for worked examples.

Property allowance or actual expenses: which applies to you?

Use this decision list before you fill in boxes 20.1 and 24 to 29.

  • If your gross rents were £1,000 or less, the property allowance gives full relief and you usually do not need to report them.
  • If your rents were over £1,000 and your costs were under £1,000, claiming £1,000 in box 20.1 may give a lower profit. Leave boxes 24 to 29 blank.
  • If you have residential mortgage interest, HMRC’s manual at PIM4460 says the allowance “is not available in a tax year where this reducer is applied”. Claim actual expenses and box 44 instead.
  • If you let a room in your own home, use the Rent a Room limit of £7,500 (£3,750 if shared) and box 37, not the property allowance.

Our guide to the £1,000 property allowance covers the rules in more detail.

How to fill in the SA105: step by step

  1. Add up all UK rents received between 6 April 2025 and 5 April 2026, including former holiday lets.
  2. Decide between the property allowance and actual expenses using the list above.
  3. Enter rents in box 20 and either the allowance in box 20.1 or expenses in boxes 24 to 29.
  4. Add any capital allowances, replacement of domestic items and private use adjustments.
  5. Work out the adjusted profit or loss in boxes 38 and 41 using HMRC’s working sheet in the notes.
  6. Enter residential finance costs in box 44 and any unused amount brought forward in box 45.
  7. File online by 31 January 2027 and pay any tax due the same day.

You can estimate the tax with our rental income tax calculator.

What landlords should do now

Gather your 2025-26 rent statements, agent statements and mortgage interest certificates now. If your qualifying income was over £50,000, you are also in Making Tax Digital for landlords for 2026-27, but the 2025-26 return is still filed in the usual way.

Frequently asked questions

Do I need a separate SA105 for each property?

No. One set of UK property pages covers your whole UK property business. Overseas property goes on the foreign pages instead.

Where do former furnished holiday lets go on the 2025-26 return?

They go in the same UK property section as your other lets. HMRC’s notes say the FHL regime was abolished from 5 April 2025 and its separate reporting was removed.

Can I claim the property allowance and mortgage interest relief?

Usually not. HMRC’s Property Income Manual says the property allowance is not available in a year when the residential finance cost reducer applies.

What is the deadline for the 2025-26 SA105?

The online return, including the SA105, must reach HMRC by 11:59pm on 31 January 2027. The paper deadline was 31 October 2026.

Which boxes are no longer used on the SA105?

The 2025-26 form says boxes 5 to 19 are no longer in use, and box 34 is not in use. Income and expenses go in boxes 20 to 45.

Sources

Rates, thresholds and rules in this guide were checked against HMRC and GOV.UK guidance on 6 November 2026. Tax rules change, so check the current position on GOV.UK or with a qualified adviser before acting. This guide is general information, not personal advice.