Self Assessment on £40,000 (UK 2026)
Self Assessment on £40,000 trading profit (UK). rUK, no expenses: Income Tax £5,486.00, Class 4 £1,645.80, total £7,131.80. With £1,000 trading allowance: total £6,871.80. Scotland (no expenses): total £7,196.87.
By Sammy S. · Founder · AuthorUpdated for 2026
Calculate from £40,000
Pre-filled with £40,000 turnover. Adjust expenses, region, or other income.
Your inputs
Turnover, expenses, region
Total trading income before expenses
Enter allowable business expenses below.
e.g. employment — affects Income Tax bands / PA taper only
Total tax + NI
rUK£7,131.80
Effective 17.83% of trading profit £40,000
If payments on account apply, each instalment is usually half of last year’s Self Assessment bill (Income Tax + Class 4), due 31 January and 31 July. Planning estimate from this year’s figures: about £3,565.90 each. Confirm with HMRC.
Class 2 treated as paid (profits ≥ £7,105).
UK Self Assessment for sole traders is estimated for tax year 2026/27: trading profit after expenses or the £1,000 trading allowance, then Income Tax (rUK or Scotland) plus Class 2/4 National Insurance. Income tax uses the same HMRC bands as our UK salary engine; NI uses the self-employed Class 2/4 engine.
Worked example — £40,000
| Trading profit | £40,000.00 |
| Income Tax | £5,486.00 |
| Class 4 NI | £1,645.80 |
| Total tax + NI | £7,131.80 |
| Take-home from trading | £32,868.20 |
£40,000 profits → Income Tax £5,486.00 + NI £1,645.80 = £7,131.80
Formulas
- Trading profitProfit = Turnover − expenses OR Turnover − min(£1,000, Turnover) if claiming the trading allowance
- Income TaxTax on (trading profit + other income) after Personal Allowance (standard £12,570, taper above £100,000)
- Class 4 NI6% between LPL and UPL; 2% above UPL — on trading profit only
- Payments on account (simplified)Each instalment ≈ 50% of (Income Tax + Class 4) for planning — confirm HMRC rules
- Work out taxable trading profit — Use allowable expenses, or claim the £1,000 trading allowance instead (not both).
- Apply Income Tax bands — Other taxable income is added for banding and PA taper only.
- Add Class 2/4 NI — Same self-employed NI rules as the National Insurance calculator.
| Personal Allowance | £12,570 | gov.uk 2026/27 |
| Trading allowance | £1,000 | gov.uk trading allowance |
| Basic-rate band (rUK) | 20% to £50,270 | gov.uk Income Tax rates |
| Class 4 main / additional | 6% / 2% | Self-employed NI |
Key takeaways — £40,000
- £40,000 rUK, £0 expenses → £7,131.80 tax+NI.
- £40,000 with trading allowance → £6,871.80.
- £40,000 Scotland → £7,196.87 (Income Tax £5,551.07).
- Effective rate on trading profit (rUK, no expenses): 17.83%.
- Add real expenses in the calculator for a closer estimate.
Self Assessment on £40,000
This page estimates UK Self Assessment for a sole trader with £40,000 turnover (modelled as taxable profit when expenses are £0).
rUK Income Tax £5,486.00 + Class 4 £1,645.80 = £7,131.80 (take-home from trading £32,868.20).
Claiming the trading allowance on £40,000 turnover reduces profit by £1,000 and changes the total to £6,871.80.
Estimates on £40,000
Tax £5,486.00 · Class 4 £1,645.80
Profit £39,000
Tax £5,551.07
rUK estimate for £40,000
Personal Allowance £12,570; taxable income £27,430.00; Income Tax £5,486.00.
Class 4 £1,645.80; total £7,131.80; take-home from trading £32,868.20.
Trading allowance on £40,000
Claiming the £1,000 allowance instead of expenses gives trading profit £39,000.00 and total tax+NI £6,871.80.
Scotland estimate for £40,000
Scottish Income Tax bands produce £5,551.07 tax on this amount (Class 4 still £1,645.80).
Checklist for £40,000
- Budget about £7,131.80 if £40,000 is taxable profit with no expenses (rUK).
- Decide expenses vs trading allowance.
- Set aside payments on account if required.
- Confirm Scotland vs rUK tax residency for Income Tax.
- Keep records for Self Assessment.
Other amounts
Self Assessment on £40,000 — FAQ
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