SA105 Property Income Form (2025/26): A Box-by-Box Guide for UK Landlords

The SA105 is where UK landlords report rental income and expenses on a self-assessment tax return. For the 2025/26 tax year (6 April 2025 to 5 April 2026), the form was renumbered: the old income boxes 5 to 19 are retired, and almost everything now flows through boxes 20 to 45. This guide maps every box on the current SA105 to plain-English guidance, with a worked example and the two points most SA105 guides still get wrong.

This is the box-by-box reference. If you want the whole return walked through end to end, see our step-by-step landlord self-assessment guide, and for the wider picture of landlord taxation see the complete landlord tax return guide for 2026.

What the SA105 is, and where property income goes on your tax return

The SA105 is the UK property supplementary pages of the SA100 self-assessment return. It captures income and allowable costs from letting UK residential and commercial property. It is not a standalone return; it sits behind your main SA100. So when people ask where you put property income on the self-assessment tax return, the answer is the SA105 pages, not the main SA100 directly and never the dividend boxes. Rent is property income, not a distribution.

Two boundaries matter from the start. First, the SA105 is for UK property only. Income from property abroad goes on the separate SA106 foreign pages, which run alongside the SA105 on the same return. Keeping the two apart matters because UK and overseas property losses cannot generally be pooled. If you let overseas, see our notes on non-resident landlord filing and report the foreign income on the SA106. Second, the SA105 reports property income, not capital gains. If you sell a rental property, the gain goes on the Capital Gains Tax summary pages, where residential disposals are taxed at 18% (basic-rate band) and 24% (above it) after the annual exempt amount of £3,000, not on the SA105.

Do you need the SA105? The £1,000 property allowance

You generally need to complete the SA105 if you receive rental income from UK property and your gross income is above the £1,000 property allowance. That covers anyone completing a return who rents out a property, including:

• Buy-to-let rental income
• Lodger income above the Rent a Room exemption
• Commercial property rental income
• Holiday letting income (the Furnished Holiday Lettings regime was abolished from 6 April 2025, so former holiday lets are now ordinary property income)
• Your share of income from jointly owned property

The property allowance (ITTOIA 2005 Part 6A) gives up to £1,000 of tax-free property income. If your gross rents are £1,000 or less for the year, you usually have nothing to report and no SA105 is required. If your gross income is higher, you can choose to claim the £1,000 allowance in box 20.1 instead of deducting actual expenses, or you can deduct your actual expenses. You cannot do both for the same property business, so compare the two and use whichever produces the lower taxable profit. Claiming the allowance only makes sense where your real expenses are below £1,000.

You still file the SA105 in a loss year, because reporting the loss is how you preserve it to carry forward against future profits.

The SA105 2025/26 box map at a glance

Boxes 5 to 19 are no longer in use on the 2025/26 form. The boxes you will actually use sit between box 1 and box 45. Verify each against the live SA105 form and SA105 notes on gov.uk when you file, because HMRC renumbers boxes between tax years.

Box	What it captures	Plain-English note
1	Number of properties rented out	A count, not addresses. One SA105 covers your whole UK property business.
3	Income from property let jointly	Put an X here if any of the property is let jointly. Report only your share.
4	Rent a Room relief claimed	X if your room rents are £7,500 or less (£3,750 if let jointly) and you are taking the relief.
20	Total rents and other income from property	Gross rental income before expenses. This is the main income box now.
20.1	Property income allowance	Claim the £1,000 allowance here instead of actual expenses.
20.2	Traditional accounting marker	X if you use accruals rather than the cash basis.
22	Premiums for the grant of a lease	From the working sheet in the SA105 notes.
24	Rent, rates, insurance and ground rents	Allowable running costs.
25	Property repairs and maintenance	Revenue repairs only, not improvements.
26	Non-residential property finance costs	Commercial interest only. Residential interest does NOT go here.
27	Legal, management and other professional fees	Letting agent fees, accountancy, allowable legal costs.
28	Costs of services provided, including wages	Cleaning, gardening, staff wages.
29	Other allowable property expenses	Anything allowable not covered above.
36	Costs of replacing domestic items (residential lettings only)	Replacement of Domestic Items relief. Replacements only, not first purchases.
37	Rent a Room exempt amount	The exempt slice if you claim Rent a Room.
38 / 40	Adjusted profit / taxable profit	From the working sheet in the SA105 notes.
39 / 41 / 42 / 43	Loss boxes	Loss b/f used, adjusted loss, loss against total income, loss to carry forward.
44	Residential property finance costs	Mortgage/loan interest on residential lets. Drives the 20% tax reducer, not a deduction.
45	Unused residential finance costs brought forward	Reducer amounts carried in from earlier years.

Income: box 20 and the rents line

Box 20 is your gross UK property income before any expenses: rent received, lease premiums (box 22 if granted in the year), reverse premiums (box 23), parking fees, retained deposits used to cover unpaid rent or damage, and lodger income above the Rent a Room exemption. Do not net off expenses here; the expenses come out in the later boxes.

Most unincorporated landlords use the cash basis by default, counting income and expenses when money actually changes hands. You must switch to traditional accruals accounting if your gross property receipts exceed £150,000 a year, and you can elect into accruals voluntarily below that figure. If you use accruals, put an X in box 20.2. The cash basis is usually simpler for smaller portfolios and matches the money in your bank, but accruals can suit landlords with large year-end debtors or significant unpaid invoices.

Completing the SA105 for two or more properties

A frequent worry is whether you need a separate SA105 for each property. You do not. One SA105 covers your whole UK property business. Put the number of let properties in box 1, then pool the income and expenses across all of them into the same boxes: all the rents go into box 20, all the repairs into box 25, all the agent fees into box 27, and so on. The form does not split figures property by property, so a landlord completing the SA105 for two properties enters a single set of combined totals.

There are only three situations where a second set of pages comes into play. You add the SA106 foreign pages if you also let property abroad. You report your own share separately where a property is jointly owned (each co-owner files their own SA105). And although UK residential and UK commercial lettings can sit in the same property business, you must still keep their finance costs apart, because residential interest belongs in box 44 (the tax reducer) while commercial interest is a full deduction in box 26. Pooling those two together is one of the errors HMRC's automated checks flag.

Expenses: boxes 24 to 29 and the repairs-versus-improvements line

The property-business expense rules borrow the trading-income deduction rules through ITTOIA 2005 section 272: a cost is allowable only if it is incurred wholly and exclusively for the letting and is revenue (running cost) rather than capital (improvement) in nature. The expense boxes are:

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

The line that catches most landlords is repairs versus improvements. A repair restores an asset to its previous condition and is allowable in box 25. An improvement creates something better than before and is capital, so it is not an expense. Replacing a broken boiler with a modern equivalent is a repair. Replacing single glazing with double glazing, or fitting a brand-new kitchen where there was none, is an improvement. Where a replacement only reflects modern equivalents of old materials (you cannot buy single glazing any more), HMRC usually accepts the modern replacement as a repair.

If you occupy part of a property you let, apportion expenses on a fair basis. Letting 75% of a property and living in 25% means claiming 75% of the shared running costs.

Residential mortgage interest: box 44 and the Section 24 reducer

This is where most self-assessment rental interest expenses are reported wrongly. For residential lettings, mortgage and loan interest is not an allowable expense. Under the Section 24 finance-cost restriction, residential finance costs go in box 44 (residential property finance costs), and HMRC turns them into a basic-rate tax reducer rather than a deduction from profit. For 2025/26 the reducer is 20% of the lower of your finance costs, your property profits, and your adjusted total income. Unused amounts carry forward in box 45.

Do not put residential mortgage interest in box 26. Box 26 is for non-residential (commercial) finance costs, which are still a full deduction because commercial lettings sit outside Section 24. For the full mechanics and worked numbers, see our guides to Section 24 tax relief and to finance costs under Section 24.

Looking ahead, the changes from 6 April 2027 are enacted law, not proposals. Finance Act 2026 (Royal Assent 18 March 2026), section 7, introduces separate property income tax rates of 22% basic, 42% higher and 47% additional for England, Wales and Northern Ireland from the 2027/28 tax year, and the Section 24 finance-cost reducer rises from 20% to 22% for the same year. Because the reducer tracks the new 22% basic rate, no new wedge opens for basic-rate landlords. Scotland sets its own income tax rates for Scottish taxpayers, so the 22/42/47 rates do not apply there. See our guide to the 2027 property tax rates and Section 24 relief.

Replacing furniture, appliances, carpets and curtains: box 36, not capital allowances

This is the section most SA105 guides get wrong. Residential landlords cannot claim the Annual Investment Allowance or other plant and machinery capital allowances on furniture, white goods, carpets or curtains inside a let dwelling. CAA 2001 section 35 expressly bars plant and machinery allowances for plant provided for use in a dwelling-house within a property business. Box 32 (Annual Investment Allowance) and box 35 (other capital allowances) exist on the SA105 for the limited cases where allowances genuinely apply, not for furnishing a flat.

The correct relief for replacing furnishings in a residential let is Replacement of Domestic Items relief (ITTOIA 2005 section 311A), claimed in box 36. The rules in plain terms:

• It covers the cost of replacing a domestic item (sofa, bed, fridge, washing machine, carpet, curtains, crockery, cutlery), not the first time you buy one. The initial purchase gets no relief at all.
• The old item must no longer be available for use in the dwelling (it is being replaced, not supplemented).
• If you upgrade, relief is restricted to the like-for-like cost. Buying a better item strips out the betterment, so a £900 premium sofa replacing a £400 basic one gives relief of about £400 plus disposal and delivery, not £900.
• Any proceeds from selling or part-exchanging the old item reduce the claim.

Capital allowances do still apply in narrow non-dwelling cases: common parts of a block (a communal boiler, lift or lighting) and integral features under CAA 2001 section 33A in qualifying non-dwelling or commercial areas, plus genuinely commercial property. For those, see the capital allowances pillar and the detail on HMO common-parts claims and the section 35 boundary. For the full replacement-relief rules, see our Replacement of Domestic Items relief guide.

A worked example: where the numbers go

Take a higher-rate landlord with one residential buy-to-let let throughout 2025/26, on the cash basis:

Item	Amount	SA105 box
Rent received (£1,200 a month)	£14,400	Box 20
Letting agent fees	£1,440	Box 27
Insurance and ground rent	£600	Box 24
Repairs (broken tap, repainting)	£900	Box 25
Replacing a worn-out washing machine, like for like	£350	Box 36
Mortgage interest	£8,000	Box 44 (reducer, not a deduction)

The taxable property profit is £14,400 minus the box 24, 25, 27 and 36 deductions (£600 + £900 + £1,440 + £350 = £3,290), so £11,110. The £8,000 of mortgage interest is not deducted. Instead it produces a Section 24 tax reducer of 20% of £8,000, which is £1,600, set against the tax due on the £11,110 profit. A landlord who wrongly put the £8,000 in box 26 or netted it off box 20 would understate their profit and overclaim relief, which is exactly the kind of error HMRC's checks pick up.

Rent a Room and lodger income

If you let furnished rooms in your own home, Rent a Room relief exempts up to £7,500 of gross receipts a year (£3,750 if the income is shared). Put an X in box 4 if your receipts are within the limit and you are claiming the relief, and enter the exempt amount in box 37. If your room income is above £7,500, you choose each year between the relief (tax-free £7,500, no expense deduction) and the normal basis (full income reported, actual expenses deducted). For the full rules, including how to work out which method is better, see our Rent a Room relief guide.

Losses: the loss boxes and how they carry

If your allowable expenses exceed your income, you have an adjusted loss for the year (box 41). A property business is not a trade, so the trade-loss rules (such as early-trade loss relief against general income) do not apply. The default treatment is to carry the loss forward against future profits of the same UK property business; the amount carried forward goes in box 43, and any loss brought forward and used against this year's profit goes in box 39.

Setting a property loss against your other income in the same year (box 42) is, in HMRC's own words on the form, unusual. It is only available for the part of a loss attributable to capital allowances or to certain agricultural expenses, not for an ordinary cash-flow loss. For most landlords the practical rule is simple: report the loss, carry it forward, and use it against the next profitable year.

Jointly owned property and Form 17

Where property is let jointly, each owner reports only their share of income and expenses on their own SA105 and puts an X in box 3. The default split depends on who you own with:

• Spouses and civil partners are taxed 50/50 on jointly held property, regardless of the actual ownership split, unless they hold it as tenants in common in unequal shares and file Form 17 with HMRC declaring the true beneficial shares, supported by evidence.
• Unmarried co-owners are taxed on their actual beneficial shares from the outset; the 50/50 default and Form 17 do not apply to them.

Each person files their own SA105 for their slice. There is no joint return; two people letting one property file two sets of property pages.

The SA105, Making Tax Digital and digital records

Making Tax Digital for Income Tax is mandatory from 6 April 2026 for landlords with qualifying income over £50,000, falling to £30,000 from April 2027 and £20,000 from April 2028. In scope, you keep digital records, send quarterly updates to HMRC and submit a final declaration through MTD-compatible software. The income and expense categories are the same as the SA105 boxes; MTD changes how and when you report, not what counts as taxable property income. For the full MTD timeline and software requirements, see our guide to Making Tax Digital for property income and the April 2026 MTD deadline.

SA105 deadlines and penalties

For the 2025/26 tax year:

• Paper return deadline: 31 October 2026
• Online return deadline: 31 January 2027
• Tax payment deadline: 31 January 2027

The late-filing penalty starts at £100 for missing the deadline, with further penalties if the return is more than three months late. Late-payment interest runs from 1 February 2027 on any unpaid tax. If you are within MTD for Income Tax, a separate points-based late-submission penalty regime applies to the quarterly updates.

Getting the SA105 right

The SA105 rewards careful record-keeping and box discipline more than anything else. The three errors that cause the most trouble are putting residential mortgage interest in the wrong place (it belongs in box 44, not box 26 and not box 20), claiming capital allowances on furnishings that section 35 bars (use box 36 instead), and getting the joint-ownership split wrong. Keep contemporaneous records, separate UK from foreign property, and keep capital improvements out of the revenue expense boxes.

Some situations are genuinely involved: mixed-use property, jointly owned portfolios, former holiday lets moving onto the standard regime, HMO common-parts claims, and onboarding to Making Tax Digital. These are where landlords most often bring in a specialist. For the return as a whole, our step-by-step self-assessment guide and the complete landlord tax return guide walk through the SA100 and payments alongside these SA105 pages.