What is the SA800 partnership tax return and who has to file one?
Hannah SimpsonChartered Accountant
Published
The SA800 is the official HMRC tax return for business partnerships, filed once a year on behalf of the partnership itself, separate from each partner's personal return. If HMRC has your business registered as a partnership, one must go in every year, and the late filing penalties multiply by the number of partners. Here is how it works in plain English.
So, what is the SA800?
The SA800 tells HMRC how much profit the partnership made during the year, how that profit was divided between the partners, and what each partner is therefore liable to pay tax on through their own Self Assessment.
Think of it as the partnership's version of a limited company's corporation tax return, with one key difference: it does not produce a tax bill for the partnership itself. It sets the numbers that feed into each partner's personal tax position. The tax is paid by the partners individually.
Who has to file an SA800?
Any business registered with HMRC as a partnership must file one each year. That includes:
- Ordinary business partnerships, where two or more people share the running of a business and split the profits
- Limited partnerships, with a mix of general and limited partners
- Limited liability partnerships (LLPs), in most cases
It does not matter how small the partnership is or how simple the finances are. If HMRC has you registered as a partnership, the return needs to go in, even in a year with little or no activity.
Who is responsible for filing it?
The nominated partner: one partner formally designated to deal with HMRC on behalf of the partnership. If nobody has been formally nominated, HMRC will usually treat the first partner listed on the registration as the nominated partner.
One signature, everyone's tax. The nominated partner submits the return, but the figures in it set every partner's personal tax position. Make sure all partners have seen and agreed the profit split before it goes in.
What information does the SA800 include?
The return covers the partnership's income and expenses for the tax year, arriving at the net profit, then sets out how that profit is allocated between the partners under the agreed profit sharing arrangement. For each partner it shows:
- Their share of the profit or loss for the year
- Any salary or interest on capital paid to that partner before the profit split
- Any adjustments affecting their individual position
Each partner then uses their allocated share on their own Self Assessment return (SA100) to calculate the Income Tax and National Insurance they owe personally.
What is the filing deadline?
The SA800 covers a tax year running 6 April to 5 April. The deadlines are:
Deadlines at a glance
- Paper return: 31 October following the end of the tax year
- Online return: 31 January following the end of the tax year
- So for the tax year ended 5 April 2026, the online deadline is 31 January 2027
Most partnerships file online for the extra three months. The SA800 also needs to be done first: each partner's personal return depends on the figures it produces, so a late partnership return squeezes everyone's January.
What happens if you miss the deadline?
HMRC issues automatic penalties for late SA800 returns, and they apply per partner, which is what makes them sting:
| How late | Penalty |
|---|---|
| Missed deadline | £100 per partner |
| More than 3 months | £10 per day per partner, up to 90 days |
| More than 6 months | A further £300 per partner |
| More than 12 months | Another £300 per partner |
The per partner multiplier adds up fast. A two partner business that files 12 months late is looking at £3,200 in partnership penalties alone (£100 + £900 daily + £300 + £300, each times two). And each partner can face separate penalties on their own SA100 if that is late too.
These figures are correct as at June 2026. Unlike personal return penalties, the 6 and 12 month charges on a partnership return are flat amounts per partner, because no tax is due at partnership level. Current rates are on the HMRC website.
What about each partner's personal tax return?
The SA800 does not replace it. Every partner must still complete their own SA100 each year, using the profit share from the SA800 to fill in the partnership pages. Two layers of filing, and the partnership layer always comes first.
One thing to have on the radar: Making Tax Digital for Income Tax began in April 2026 for sole traders and landlords with qualifying income over £50,000. Partnerships are not yet within MTD, but they are expected to be brought in later, so digital record keeping now is a sensible head start.
What if the profit split changed during the year?
More common than people think. A partner joins or leaves mid year, or the partners agree a new ratio part way through. The SA800 must reflect the change accurately, with the right allocation applied to the right periods.
Getting this wrong causes problems for the partnership return and for each partner's personal position, so document any changes clearly and tell your accountant before the partnership accounts are finalised.
Frequently asked questions
Does the partnership itself pay tax?
No. The partnership files the SA800 to report profit and how it was shared, but the tax is paid by each partner individually through their own Self Assessment, based on their share. That is also why late filing penalties on the SA800 are flat amounts rather than a percentage of tax.
Do I still file an SA800 if the partnership made a loss?
Yes. The return must be filed whether the partnership made a profit, a loss, or barely traded. Losses are allocated between partners in the same way as profits, and each partner may be able to use their share against other income on their own return.
Can a husband and wife business be a partnership?
Yes, and many are. If you run the business together and share the profits, HMRC can treat it as a partnership that must register and file an SA800, with both of you filing personal returns. Whether a partnership is the best structure is a separate question worth reviewing properly.
What happens if a partner leaves during the year?
The SA800 still covers the full year, with profits allocated to each partner for the period they were a partner. The leaver still needs their share for their personal return, so keep contact details and make sure the split for their period is agreed before filing.
Ready to get your partnership accounts and SA800 sorted?
At HLS Accounts in Cardiff, we prepare partnership accounts and file the SA800 for business partnerships across South Wales. We agree the profit split with you, produce clear partner statements, and give each partner the figures they need for their own Self Assessment, all explained in plain English.
Book a free consultation or call us on 02922 805941.
