SA103S or SA103F: which self-employment pages to fill in

Most sole traders with turnover under £90,000 and a simple set of accounts should fill in the SA103S short self-employment pages. You need the SA103F full pages if turnover was £90,000 or more, or if your profits need adjusting, for example because your accounts did not run to 31 March or 5 April 2026. Both are for the 2025-26 return due online by 31 January 2027.

What are the SA103S and SA103F?

They are the two versions of the self-employment supplementary pages that go with the main SA100 tax return. You fill in one set for each business you run as a sole trader.

Both forms and their notes for 2025-26 were published on GOV.UK on 6 April 2026. If you file online, HMRC’s service asks the questions and shows you the right version.

When can you use the SA103S short pages?

You can use the short pages if your turnover was under £90,000 and your affairs are straightforward. GOV.UK describes the SA103S as for people with “relatively simple tax affairs” whose turnover was below the VAT threshold for the year.

HMRC’s 2025-26 notes add that, if you traded for less than a year, the test is whether turnover would have been £90,000 or more over a full 12 months.

When must you use the SA103F full pages?

You must use the full pages if any of these apply.

• Your turnover was £90,000 or more, or would have been over a full year.
• The date your books are made up to (box 7 on the short pages) is before 31 March 2026 or after 5 April 2026, unless you stopped trading.
• Your accounting period was not 12 months long, so profits need adjusting to the tax year.
• You have adjustment income because you changed your accounting basis.
• Your affairs are otherwise complex, for example you need to show disallowable expenses line by line.

HMRC’s notes say to read the full list in the short notes before you start. If you are unsure, the full pages are always acceptable.

Which applies to you?

Use this decision list.

• If you are a new sole trader with turnover under £90,000 and you made up accounts to 5 April 2026, use the SA103S.
• If you crossed £90,000 or registered for VAT, use the SA103F.
• If your accounts run to 30 June or 31 December, use the SA103F, because profits must be apportioned to the tax year.
• If your gross income was £1,000 or less, you may not need either page. The trading allowance gives full relief. See claiming the trading allowance.
• If you are in a partnership, use the partnership pages, not the SA103.

Key boxes on the SA103S

The short pages follow a simple order: business details, income, expenses, then tax adjustments.

1. Business details. Description, postcode and the date your books are made up to (box 7). From 2025-26, you must also say whether the business started or stopped in the year and give the dates.
2. Income. Turnover goes in box 9 and other business income in box 10.
3. Trading allowance. Claim it in box 10.1. HMRC’s notes say that if you do, you cannot deduct any allowable expenses or claim any other allowances.
4. Expenses. Itemise them in boxes 11 to 19, or, with turnover under £90,000, enter one total in box 20.
5. Profit, capital allowances and losses. The later boxes work out net profit or loss and record capital allowances and any loss relief.

Our guide to sole trader expenses explains which costs you can claim.

Cash basis or traditional accounting?

Since 6 April 2024 the cash basis is the standard way for sole traders to work out profits. GOV.UK says you record income when you receive it and expenses when you pay them.

You can choose traditional (accruals) accounting instead, but you must say on your return that you used it. Limited companies cannot use the cash basis.

National Insurance on your profits

Your self-employment profits also set your Class 4 National Insurance. For 2025-26 Class 4 is 6% on profits between £12,570 and £50,270 and 2% above that. HMRC works this out from the figures on your SA103.

Class 2 is no longer compulsory. You can pay it voluntarily to protect your State Pension record if profits are low. Try our self-employed take-home pay calculator to see the effect.

What to do now

1. Check last year’s turnover against the £90,000 test.
2. Confirm your accounting date falls between 31 March and 5 April 2026.
3. Note your start or cessation dates if either fell in 2025-26.
4. Gather your business records and file by 31 January 2027.

If you are new to self-employment, read your first year as a sole trader too.

Frequently asked questions

What is the turnover limit for the SA103S short pages?

For 2025-26 the short pages are for turnover under £90,000. If you traded for part of the year, the test is whether turnover would have reached £90,000 over 12 months.

Can I use the SA103S if my accounts end on 31 December?

No. HMRC’s notes say you need the full pages if the date your books are made up to is before 31 March 2026 or after 5 April 2026, unless you stopped trading.

Can I claim the trading allowance and expenses?

No. If you claim the £1,000 trading allowance in box 10.1, you cannot deduct allowable expenses or claim other allowances for that business.

Do I need one SA103 for each business?

Yes. You fill in a separate set of self-employment pages for each trade you run as a sole trader.

Is the cash basis compulsory?

No. It is the standard method since 6 April 2024, but you can opt for traditional accounting and must say so on your return.