A partnership does not pay income tax on its profits, but it must file a Partnership Tax Return (form SA800) showing what the firm made and how that profit is split between the partners. The nominated partner files it, by 31 October for a paper return or 31 January for an online one, and every partner then copies their own share from the partnership statement onto the partnership pages of their personal Self Assessment return.
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Who has to file the partnership return, and who signs it?
When a business is carried on by two or more people in partnership, section 12AA of the Taxes Management Act 1970 lets HMRC issue a notice requiring a return from the person identified in the notice. GOV.UK guidance calls this person the nominated partner: they register the partnership for Self Assessment, manage the partnership’s tax returns and keep the business records. Each partner registers and files separately. Registration is due by 5 October in the business’s second tax year, so a partnership that started in the 2025 to 2026 tax year should have registered by 5 October 2026. Paper registration uses form SA400 for the partnership and SA401 for a partner.
HMRC’s Partnership Manual (PM143000) says “nominated partner” and “representative partner” mean the same thing. If the nominated partner becomes unavailable, their successor is responsible and the change must be notified. HMRC can instead require any partner to file, usually the first active partner alphabetically.
The SA800 is used by general partnerships under the Partnership Act 1890, limited partnerships under the Limited Partnerships Act 1907 and limited liability partnerships. An LLP that does not carry on a business with a view to profit, or is being formally wound up, may need a Corporation Tax return instead.
What goes on the SA800?
Every partnership receives the core eight pages, which cover trading and professional income and interest from banks and building societies. Other income needs supplementary pages: SA801 for UK property, SA802 for foreign income, SA803 for disposals of chargeable assets and SA804 for savings, investments and other income. The full partnership statement, SA800(PS), is needed where the short statement is not enough.
For trading income the return covers the accounting period or periods ending in the tax year. The 2025 to 2026 return therefore shows accounts ending between 6 April 2025 and 5 April 2026, while taxed savings income is returned for the tax year itself. Where any partner pays income tax, section 849 of the Income Tax (Trading and Other Income) Act 2005 (ITTOIA) requires the profit to be calculated as if the firm were a UK resident individual. Company partners and non resident partners need further computations (PM163030).
Partnerships with turnover of £15 million or more, and partnerships whose members are all companies, send full accounts and computations instead of completing the standard accounts boxes (PM145200). A return is treated as incomplete unless it gives the name, address and Unique Taxpayer Reference (UTR) of everyone who was a partner at any point in the period (PM145100). A partner without a UTR applies on SA401, or SA402 if the partner is not an individual.
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What is the partnership statement?
Section 12AB of the Taxes Management Act 1970 requires every partnership return to include a partnership statement. It shows the income or loss from each source for each period of account ending in the return period, the tax deducted, and each partner’s share of those amounts.:
- the short statement on pages 6 and 7 suits firms with only trading income and bank or building society interest, and has room for three partners;
- the full statement, SA800(PS), covers every type of partnership income and has room for six partners; for more partners you photocopy the partner page;
- more than one statement is needed if the firm has two accounting periods ending in the same tax year, more than one trade, or company or non resident partners;
- if profits are not split on a simple percentage, for example because one partner has a salary or a fixed share, the arrangement must be explained in box 3.116, “Additional information”.
How the shares are worked out, including what happens when salaries push another partner into a notional loss, is covered in how partnership profits are shared for tax. A partnership that has another partnership as a member must, unless it names the indirect partners, calculate that member’s share on four bases: as a UK resident individual, a non resident individual, a UK resident company and a non resident company (PM145120).
When is the return due, and what happens if it is late?
For 2025 to 2026, HMRC’s Partnership Tax Return Guide (SA850) gives a deadline of 31 October 2026 for paper returns and 31 January 2027 for online returns. Under section 12AA(4D) and (4E), if the notice is given after 31 July, a paper return is due three months after the notice (an online return keeps 31 January), and if it is given after 31 October, both are due three months after the notice. A company partner can change the filing date (PM147000).
The penalties are charged on every person who was a partner during the return period, not just the nominated partner:
| How late | Penalty for each partner |
|---|---|
| After the deadline | £100 |
| Over 3 months | £10 a day for up to 90 days (maximum £900) |
| Over 6 months | £300 |
| Over 12 months | A further £300 |
A five partner firm that files more than a year late therefore faces penalties of up to £1,600 per partner. Only the nominated partner, or their successor, can appeal, and the appeal is treated as covering every partner (PM148000). Errors are also expensive: if the return is wrong because of a failure to take reasonable care, each partner can face a penalty of 30% to 100% of the tax understated on their share, rising to 200% where offshore income or gains are involved. See Self Assessment deadlines and penalties and reasonable excuse.
How does each partner report their share?
An individual partner reports their share on the partnership pages (SA104S short or SA104F full) of their own return, not the self employment pages (PM146100). On the short pages, box 8 takes the profit or loss from box 11 or 12 of the partner’s partnership statement. Each partner is personally responsible for the income tax and Class 4 National Insurance on their share and pays through their own Self Assessment account; see self employed National Insurance. A company partner simply includes its share in its company tax return.
Since 2024 to 2025, partners have been taxed on the profit arising in the tax year rather than on an accounting year ending in it (BIM81201). If the partnership’s year end is not between 31 March and 5 April, the figure on the statement will not be the taxable amount, and the partner enters an adjustment in box 9. The SA850 guide warns that the firm may need to give partners extra information about their share for the period from the end of the accounting period to 5 April. The background is explained in basis period reform.
Illustration only. A firm draws up accounts to 31 December. Partner A’s share for the year to 31 December 2025 is £60,000, and her expected share for the year to 31 December 2026 is £66,000. Her 2025 to 2026 profit is the share of 6 April to 31 December 2025 (270 days) plus the share of 1 January to 5 April 2026 (95 days): £60,000 × 270/365 = £44,384, plus £66,000 × 95/365 = £17,178, a total of £61,562. She puts £60,000 in box 8 and an adjustment of £1,562 in box 9. Because the 2026 figure is an estimate, it is a provisional figure that must be corrected once the accounts are final.
What if a partner disagrees with their allocation?
Section 12ABZB of the Taxes Management Act 1970 makes the partnership return conclusive about whether someone has a share in the profits or losses and how much that share is. A partner who disagrees must still enter the figure from the statement on their own return, but can refer the dispute to the First tier Tribunal within 12 months beginning with the day after the return (or an amendment) was delivered. They must tell HMRC and the reporting partner at the same time, and the reporting partner must tell the other partners. The referral cannot be about the total profit of the firm, only about how it is shared (PM150000).
What mistakes cause problems on partnership returns?
- Filing late because one partner’s figures are missing. Each partner is penalised, so a provisional figure, corrected later, is usually better than a late return.
- Leaving out partners who joined or left in the period. The business is treated as continuing if at least one partner is in it both before and after the change, but the partner details and profit shares must show who was a partner for which part of the period.
- Missing UTRs, which make the return incomplete.
- Giving partners the statement figure without the information they need for the tax year adjustment.
- Partners entering their share on the self employment pages, or using a figure that does not match the statement.
HMRC normally has 12 months from receipt of the return to open an enquiry into it. An enquiry into the partnership return feeds through to every partner’s return; see what happens in an HMRC compliance check.
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Related Accountapedia entries
- The nominated partner’s duties
- Registering for Self Assessment and getting a UTR
- Partners joining and leaving: the tax consequences
- Non resident partners in a UK partnership
- Completing the partnership pages (SA104)
- How HMRC enquiries into partnership returns work
Sources
- legislation.gov.uk: Act 1970 c. 9, section 12AA
- GOV.UK: Set up business partnership
- GOV.UK: Manual page PM143000
- GOV.UK: Self assessment partnership tax return sa800
- legislation.gov.uk: Act 2005 c. 5, section 849
- GOV.UK: Manual page PM163030
- GOV.UK: Manual page PM145200
- GOV.UK: Manual page PM145100
- legislation.gov.uk: Act 1970 c. 9, section 12AB
- GOV.UK: Manual page PM145120
Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 8 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.