SA105, box by box
SA105 is the page of your Self Assessment return for rent from UK property. Boxes 1 to 4 describe your letting, 20 to 29 take your income and expenses, and the rest cover adjustments, allowances, your profit or loss and mortgage interest. Boxes 5 to 19 and 34 aren’t used.
Checked against GOV.UK by Cristiano Betta of Work Betta Ltd, which makes Tillslip, on : SA105 and its notes, 2025–26.
Your letting
| What goes in it | Box |
|---|---|
| Number of properties you rent out | 1 |
| Tick if all your property income stopped in 2025–26 and won’t start again in 2026–27 | 2 |
| Tick if you let property jointly; then enter only your share of the income and expenses | 3 |
| Tick if you claim Rent a Room relief and your rents are £7,500 or less (£3,750 if let jointly) | 4 |
Income
| What goes in it | Box |
|---|---|
| Total rents and other income from property | 20 |
| Property income allowance, instead of claiming any expenses | 20.1 |
| Tick if you used traditional accounting rather than cash basis | 20.2 |
| Tax taken off income in box 20: non-resident landlords only | 21 |
| Premiums for the grant of a lease, from the working sheet in the notes | 22 |
| Reverse premiums and inducements | 23 |
Expenses
| What goes in it | Box |
|---|---|
| Rent, rates, insurance and ground rents | 24 |
| Property repairs and maintenance | 25 |
| Non-residential property finance costs | 26 |
| Legal, management and other professional fees | 27 |
| Costs of services provided, including wages | 28 |
| Other allowable property expenses | 29 |
Adjustments and allowances
| What goes in it | Box |
|---|---|
| Private use adjustment: the non-business part of anything in boxes 24 to 29 | 30 |
| Balancing charges, after selling or no longer using an asset you claimed allowances on | 31 |
| Annual Investment Allowance | 32 |
| The Structures and Buildings Allowance | 33 |
| Electric charge-point allowance | 33.1 |
| Freeport and Investment Zones Structures and Buildings Allowance | 33.2 |
| Zero-emission car allowance | 34.1 |
| All other capital allowances | 35 |
| Costs of replacing domestic items | 36 |
Profit or loss
| What goes in it | Box |
|---|---|
| Rent a Room exempt amount, if Rent a Room income is in box 20 | 37 |
| Adjusted profit for the year, from the working sheet | 38 |
| Losses from earlier years used against this year’s profit | 39 |
| Taxable profit for the year: box 38 minus box 39 | 40 |
| Adjusted loss for the year, from the working sheet | 41 |
| Loss set off against your total income for 2025–26, which is unusual | 42 |
| Loss to carry forward to the following year | 43 |
Mortgage interest
| What goes in it | Box |
|---|---|
| Residential property finance costs | 44 |
| Unused residential property finance costs brought forward | 45 |
Cash basis or traditional accounting
Cash basis is the default: you count rent when you get it and costs when you pay them. Tick box 20.2 only if you used traditional accounting instead.
Which expenses go where
Boxes 24 to 29 take your running costs, and box 36 the cost of replacing furniture and appliances. The landlord expenses guide lists what goes in each, with examples.
Landlord allowable expenses, box by box
Letting jointly
If you own and let a property with someone else, tick box 3 and enter only your share of its income and expenses.
Mortgage interest isn’t an expense
Interest on a mortgage or loan for a residential let goes in box 44, not with your expenses, and reduces your tax instead. Any you couldn’t use in earlier years goes in box 45.
Tillslip fills in the totals
Snap each receipt and Tillslip adds it to the right SA105 box, per property, ready for the return or your accountant.
Also: Landlord expenses · Mileage calculator · Mileage rates · Keeping receipts · Self-employed expenses · Landlord expenses spreadsheet