SA800 filing in Tax Optimiser is in closed beta with accountancy firms and is not yet open to the public. For firms in the beta, Tax Optimiser can prepare and file the SA800 Partnership Tax Return for client partnerships — the annual return every UK partnership must send to HMRC, reporting the business’s income and how the profit was shared between the partners. You enter the return in a six-step wizard, the arithmetic boxes calculate themselves as you type, you can print the official SA800 form at any point, and you submit to HMRC without leaving Tax Optimiser.
Who this is for
The feature applies to client organisations whose structure is a Limited Liability Partnership or an ordinary Partnership — the Partnership return (SA800) menu section only appears for those organisations. The partnership itself pays no tax on the return: the SA800 reports the results and the Partnership Statement allocates them, and each partner then carries their own share onto the partnership pages of their personal return. If you also prepare the partners’ personal Self Assessment returns, Tax Optimiser’s Self Assessment (beta) feature covers those, including the SA104 partnership pages.
What is supported today
The beta supports the 2025-26 return with:
- The full trading income & expenses page (boxes 3.29–3.73) — also valid below the £90,000 three-line-accounts threshold, so one screen serves every partnership up to the form’s £15 million turnover limit — with the capital allowance pools, an optional breakdown of disallowable expenses, and the start and cessation dates of the business
- Partnerships with no trade — property or investment partnerships file without the trading pages at all
- The summary balance sheet (boxes 3.99–3.115)
- The Partnership Statement — any number of partners, with each share checked against the return
- The supplementary pages: Land & Property (SA801) with its expense and tax-adjustment boxes and residential finance costs, Foreign (SA802) savings and dividends, Chargeable Assets (SA803) listed asset by asset, and Savings (SA804) interest, dividends and other income
- Partner and agent declarations, provisional figures and the rest of page 8, and amended returns
- A populated, printable copy of the official SA800 form, with a schedule for everything the printed form has no box for
- Direct filing to HMRC over their online channel, with the return checked before it is sent, signed, and tracked until HMRC answers
Not yet supported: more than one trade or accounting period on a return, foreign property and offshore funds on SA802, and returns for years other than 2025-26.
Every calculated box on the form — net profit (3.65), net business profit for tax (3.73), the balance sheet totals, the partners’ closing balance — is derived for you and shown read-only, so the return can never disagree with its own arithmetic.
How the return comes together
The wizard walks the form in the order an accountant naturally works: partnership details, trading income, balance sheet, partners, supplementary pages, then a review step that summarises the whole return before anything is sent. Each step’s bubble gains a green tick once that step has what the return needs from it, and a red count whenever something on it would stop the return being filed, so you can see at a glance where there is still work to do.
