Self-employment & Uk property

These forms report business and property income on the Self Assessment return. SA103F (full) and SA103S (short) report the income and expenses of a self-employed business, with the short page used where annual turnover is below £90,000; and SA105 reports rental profits or losses from UK property. The appropriate form depends on the type and size of the income.

SA103F Self-employment (full) 2026

Purpose

The SA103F is the full Self Assessment page for sole traders and self-employed people. It is used to report the income and expenses of a self-employed business and to calculate the taxable profit or loss and the related National Insurance contributions. The full page is used when the business is more complex than the short version allows, in particular when annual turnover is £90,000 or more, or when the person needs to enter detailed disallowable expenses, capital allowances, accounting adjustments, losses or other business-related information that requires more detailed reporting to HMRC.

Deadlines

The SA103F is a supplementary page to the SA100, so for 2026–27 it must be filed by 31 October 2027 on paper or by 31 January 2028 online. The tax and Class 4 National Insurance due for the year are payable by 31 January 2028, together with the first payment on account for 2027–28 and, if applicable, the second payment on account by 31 July 2028. A sole trader must register for Self Assessment by 5 October after the end of the tax year in which the business began, and the standard £100 late-filing penalty and daily penalties may apply if the return is submitted late, with further penalties and interest possible for continued delays in filing or payment.

Requirements

The taxpayer needs a complete record of all business income and allowable expenses for the year, such as sales invoices, bank statements, receipts, mileage records, stock records and fixed asset purchases and sales. Accounts (or the cash basis summary), the capital allowances pool balances, loss records from earlier years, CIS deduction statements from contractors, and the UTR are also needed. Personal or private costs must be excluded, and expenses with a private element must be apportioned.

Filing Process

Start with the business details: the business name if it is not your own name (box 1), a description of the business (box 2), the business address and postcode (boxes 3 and 4) and a tick in box 5 if any of these changed. Say whether the business started after 5 April 2026 (box 6Q and date in box 6), whether it ceased before 6 April 2026 (7Q and date in box 7), the dates on which the books start and end (boxes 8 and 9), and tick box 10 if traditional accounting rather than cash basis was used. Boxes 13 and 14 cover special arrangements and last year's provisional profit. In Business income, box 15 is the turnover, meaning the takings, fees, sales or money earned by the business, and it is the mandatory revenue figure. Box 16 is any other business income and box 16.1 is the trading income allowance if claimed. In Total expenses, enter the allowable business expenses in boxes 17 to 30: cost of goods bought for resale, construction subcontractor payments, wages and staff costs, car, van and travel costs, rent, rates, power and insurance, repairs, phone and office costs, advertising and entertainment, interest, bank charges, bad debts, accountancy and legal fees, depreciation and other expenses. Box 31 is the total of boxes 17 to 30 and, if turnover is below £90,000, just the total can be entered in box 31. Boxes 32 to 46 are used to show how much of each expense is disallowable for tax, with the total in box 46. Box 103 is for other information.

SA103S Self-employment (short) 2026

Purpose

The SA103S is the simplified Self Assessment page for sole traders whose business is straightforward and whose annual turnover is below £90,000. It lets the taxpayer report the business income, enter allowable expenses in summary form (or as a single total) and calculate the taxable profit or loss, with fewer boxes than the full page. It is intended for small businesses such as freelancers, tradespeople and consultants who do not need detailed adjustments or a balance sheet.

Deadlines

Section 455 tax is due 9 months and 1 day after the end of the accounting period in which the loan was made. The CT600A is filed with the CT600, normally within 12 months of the period end.

Requirements

The company must have a full loan account or director's loan account ledger showing every advance, repayment, write-off and release during the period and the dates on which they happened. It needs the names of all participators and associates who received loans or benefits, the balance outstanding at period end, and evidence of any repayments, board minutes or dividends used to clear the loans. The company must also know the section 455 rate that applies to the loans (33.75 per cent for loans made before 6 April 2026; the rate has been increased from 33.75% to 35.75% per cent for loans after 6 April 2026).

Filing Process

In the Business details section, enter a description of the business (box 1), the business postcode (box 2), a tick if details have changed (box 3), whether you are a foster carer or shared lives carer (box 4), whether the business started after 5 April 2026 and the start date (boxes 5Q and 5), whether it ceased before 6 April 2026 and the date (6Q and 6), the date to which books or accounts are made up (box 7) and tick box 8 if you used traditional accounting rather than cash basis. In Business income, enter the turnover (box 9), which is the takings, fees or sales of the business and is the mandatory revenue figure, then any other business income (box 10) and the trading income allowance (box 10.1) if you are claiming it instead of deducting expenses. For allowable expenses, enter the costs of goods bought for resale (box 11), car, van and travel costs after private use (box 12), staff costs (box 13), rent, rates, power and insurance (box 14), repairs (box 15), accountancy, legal and professional fees (box 16), interest and bank charges (box 17), phone and office costs (box 18) and other allowable expenses (box 19). Box 20 is the total of boxes 11 to 19, or, if turnover is below £90,000, you may just enter the total expenses in box 20. Box 21 is the net profit (box 9 plus box 10 minus box 20, if positive) and box 22 is the net loss. Next enter capital allowances: Annual Investment Allowance (box 23), the small balance allowance (24), zero-emission car allowance (24.1), other allowances (25) and structures and buildings allowances (25.1 and 25.2), and balancing charges in box 26. Add goods and services for own use (box 27). Box 28 is the net business profit for tax purposes, from which brought forward losses (box 29) are deducted, and other business income (box 30) is added to give the total taxable profit in box 31, or the loss in box 32. Boxes 33 to 35 deal with losses set against other income, carried back or carried forward, boxes 36 and 37 are the National Insurance options, and box 38 is for CIS deductions.

SA105 UK Property 2026

Purpose

The SA105 reports rental profits or losses from UK property (houses, flats, land, holiday lets) for a Self Assessment tax year. It records rents and other receipts, allowable expenses, capital allowances and losses so that taxable property profit can be calculated. Use it when property income is above £1,000 or the property allowance is not enough.

Deadlines

Filed with the SA100: 31 October 2027 (paper) or 31 January 2028 (online) for 2026–27. Tax is due by 31 January 2028, with payments on account due on 31 January and 31 July 2028, where applicable. A standard £100 late-filing penalty applies if the return is late, with additional daily penalties and further charges possible for continued delays.

Requirements

Records of every rent received, tenancy agreements, receipts for expenses, mortgage interest statements, capital allowance details, joint ownership shares and any losses carried forward. UTR and the main SA100 are needed.

Filing Process

Property details: box 1 is the number of properties rented out; box 2 is ticked if all property income stopped in 2026-27 and none is expected in 2026-27 (then consider the Capital Gains Tax summary); box 3 is ticked for jointly let property; box 4 is ticked if Rent a Room relief is claimed and rents are £7,500 or less (£3,750 if joint). Boxes 5 to 19 are no longer used. Income: box 20 is total rents and other property income (the mandatory revenue figure), box 20.1 the £1,000 property income allowance if used instead of expenses, box 20.2 a tick for traditional accounting rather than cash basis, box 21 tax already taken off the income, box 22 premiums for the grant of a lease (from working sheet box E) and box 23 reverse premiums and inducements. Expenses: box 24 rent, rates, insurance and ground rents; 25 repairs and maintenance; 26 non-residential finance costs; 27 legal, management and professional fees; 28 services including wages; 29 other allowable expenses. Taxable profit or loss: box 30 private use adjustment; 31 balancing charges; 32 Annual Investment Allowance; 33 Structures and Buildings Allowance; 33.1 electric charge-point allowance; 33.2 Freeport and Investment Zones allowance; 34.1 zero-emission car allowance; 35 other capital allowances; 36 replacement of domestic items (residential lettings only); 37 Rent a Room exempt amount. Box 38 is the adjusted profit (use the notes working sheet), 39 losses brought forward used, 40 taxable profit (38 minus 39). If there is a loss, box 41 is the adjusted loss, 42 loss set against 2026-27 total income (unusual), 43 loss carried forward. Boxes 44 and 45 record residential property finance costs and unused costs brought forward, used for the 20 per cent tax reduction. Box 34 is not in use.