Help Centre · Partnership Returns (Beta) · 4 min read

SA800 trading income and expenses

The full SA800 income and expenses page, or the three-line boxes 3.24 to 3.26 below £90,000: entering income and expense totals, the capital allowance pools, an optional breakdown of disallowables, and how the calculated boxes 3.65 and 3.73 drive the rest of the return.

Tax Optimiser Updated 30 Oct 2026
Beta feature — Partnership (SA800) returns are in beta and open to everyone — accountant firms and partnerships filing their own return — for the 2025-26 tax year. If anything looks wrong, email support@taxoptimiser.co.uk and the team will help.

The Trading Income step is the heart of the return: the SA800’s full income & expenses page (boxes 3.29–3.73). The full page works for every partnership. If annualised turnover was under £90,000 you can instead tick Turnover under £90,000 at the top of the step and fill in just the three-line boxes: 3.24 (turnover and other business income, plus any balancing charges from box 3.23), 3.25 (allowable expenses, leaving out disallowable costs such as depreciation, plus capital allowances from box 3.22) and the calculated 3.26, which becomes the taxable profit or loss. The £90,000 is for a full year, so a shorter period is scaled up before it is checked. Detailed figures you have already entered are kept but not sent while the box is ticked.

The Turnover under £90,000 tick with the three-line boxes: turnover 3.24, expenses 3.25 and the calculated net profit 3.26

Two ticks on the Details step change what this step needs: box 3.10 when boxes 3.14 to 3.93 and 3.99 to 3.115 aren’t needed at all (for example no accounts for the trade end in the year), and box 3.11 when the accounts don’t cover the period from the last accounting date — explain why in the additional information box.

The Details step ticks: traditional accounting (3.9), details not required (3.10), accounts not covering the period (3.11), agent declaration and amended return

Entering the figures

Every money box works the same way: type the amount (the £ sign, commas and spaces are all tolerated), and boxes that can go negative accept brackets — (1,500) means minus 1,500, matching how the form itself shows losses. Boxes with a grey tint are calculated and read-only; each one explains its own arithmetic underneath.

The Trading Income step: income boxes 3.29 and 3.50 and the expenses group, boxes 3.46 to 3.63

Income and expenses

  • Income: sales/business income (box 3.29) and other income/profits (3.50). Goods taken for personal use go in box 3.67 with the tax adjustments, not in box 3.29.
  • Expenses (boxes 3.46–3.63): entered at their full amounts including any disallowable part — cost of sales, subcontractor costs, employee costs, premises, repairs, admin, motor, travel, advertising, legal, bad debts, interest and finance charges, depreciation, and other expenses. The disallowable total is added back separately in box 3.66.

If “no trade or profession” is ticked on the Details step, this step and the Balance Sheet step show a notice and must be left empty — nothing on them is sent to HMRC.

Capital allowances and balancing charges

The capital allowances group: boxes 3.13A to 3.21 with the calculated totals 3.22 and 3.23

Each kind of allowance has its own box, as on the form: the Annual Investment Allowance (3.13A), the zero-emission goods vehicle allowance (3.14), main rate (3.14A) and special rate (3.16) allowances on equipment and cars, the zero-emission car allowance (3.16A), electric charge-points (3.18), structures and buildings (3.18A, and 3.18B for freeports and investment zones), and other capital allowances (3.20). Balancing charges go beside the pool they belong to (3.15A, 3.17) or in other balancing charges (3.21). Total capital allowances (3.22) and total balancing charges (3.23) are calculated.

Tax adjustments and the calculated result

The tax adjustments group with the calculated boxes 3.65 and 3.73
  • Net profit/(loss) (3.65) — calculated: gross profit (3.49) + other income (3.50) − total expenses (3.64).
  • Disallowable expenses (3.66) and goods taken for personal use (3.67) add back to profit. Depreciation (box 3.62) is never allowable, so box 3.66 must be at least the depreciation figure — the Review step tells you if it isn’t.
  • Deductions from net profit other than capital allowances (3.71).
  • Net business profit for tax purposes (3.73) — calculated: 3.65 + 3.66 + 3.67 + balancing charges (3.23) − capital allowances (3.22) − other deductions (3.71). This figure drives the whole return: a positive result becomes the taxable profit (3.83) and a negative one the allowable loss (3.84), and those are exactly what the Partnership Statement must allocate to the partners.
  • Adjustment on change of accounting basis (3.82) — carried to box 11A of the Partnership Statement.
  • CIS deductions (3.97) for tax deducted by contractors under the Construction Industry Scheme. It flows to box 24 of the Partnership Statement.
  • Tax taken off trading income (3.98), other than CIS deductions — mainly for ‘CT partnerships’. HMRC’s online return carries it as box 24A of the Partnership Statement, split by profit-share %.
  • Net partnership charges paid (3.117) — charges not already deducted as an expense; carried to box 29 of the Partnership Statement.

Breaking down the disallowable expenses (optional)

The disallowable expenses by category group: boxes 3.30 to 3.43 with the calculated boxes 3.44 and 3.45

Box 3.66 is the one figure you must enter. If you want the return to show which expenses were disallowed, enter the amounts against their categories in boxes 3.30 to 3.43. Depreciation is always filed as box 3.44, and whatever is left of box 3.66 is filed as other expenses (3.45), shown calculated at the bottom of the group. The itemised amounts cannot add up to more than box 3.66.

Next: the balance sheet.

The short version

SA800 trading income and expenses — in brief

The Trading Income step implements the SA800's full income and expenses page, boxes 3.29 to 3.73, or, ticked for annualised turnover under £90,000, the three-line boxes 3.24 (turnover plus balancing charges), 3.25 (allowable expenses plus capital allowances) and the calculated 3.26.

Expenses are entered at their full amounts; the disallowable part is added back in box 3.66 and can optionally be broken down by category.

Each capital allowance pool has its own box, with the totals 3.22 and 3.23 calculated.

Boxes 3.65 and 3.73 are calculated read-only, and 3.73 becomes the taxable profit (3.83) or allowable loss (3.84) that the Partnership Statement allocates.