UK Self-Employment Tax Calculator
Calculate your total tax liability as a self-employed sole trader for the 2025/26 or 2026/27 tax year. See your income tax, Class 2 and Class 4 National Insurance, and payments on account.
Total Tax
£8,621.60Effective rate: 19.16%
Net Income
£36,378.40After all taxes
Net Profit
£45,000After expenses
| Item | Amount |
|---|---|
| Gross Income | £50,000 |
| Business Expenses | −£5,000 |
| Net Profit | £45,000 |
| Income Tax | £6,486.00 |
| Class 2 National Insurance | £189.80 |
| Class 4 National Insurance | £1,945.80 |
| Total Tax | £8,621.60 |
| Net Income | £36,378.40 |
Payments on Account
HMRC requires two payments on account: £4,310.80 each, due 31 January and 31 July.
National Insurance for the self-employed (2026/27)
| National Insurance | Rate | Applies to |
|---|---|---|
| Class 2 (voluntary) | £3.65/week | Optional below the £7,105 small-profits threshold, to keep State Pension credits |
| Class 4 (main) | 6% | Profit from £12,570 to £50,270 |
| Class 4 (additional) | 2% | Profit above £50,270 |
For 2025/26 Class 2 was £3.5/week (SPT £6,845); Class 4 rates and the £12,570/£50,270 bands are unchanged.
Income tax + Class 4 NI by profit (2026/27)
England/Wales income tax on net profit (after the £12,570 Personal Allowance) plus Class 4 NI. Excludes the optional Class 2 and the £1,000 trading allowance.
| Net profit | Income tax | Class 4 NI | Total | Take-home |
|---|---|---|---|---|
| £20,000 | £1,486 | £446 | £1,932 | £18,068 |
| £30,000 | £3,486 | £1,046 | £4,532 | £25,468 |
| £50,000 | £7,486 | £2,246 | £9,732 | £40,268 |
| £70,000 | £15,432 | £2,657 | £18,089 | £51,911 |
| £100,000 | £27,432 | £3,257 | £30,689 | £69,311 |
First payment on account (50% of this year's bill) is due 31 January, the second 31 July. Scotland uses different income-tax bands.
Frequently asked questions
What taxes do self-employed people pay in the UK?
Self-employed individuals in the UK pay income tax on their net profit (after allowable expenses), Class 2 National Insurance (a flat weekly rate of £3.50 in 2025/26 if profits exceed the Small Profits Threshold of £6,845), and Class 4 National Insurance (6% on profits between £12,570–£50,270 and 2% above £50,270).
What are payments on account?
Payments on account are advance payments towards your tax bill. HMRC requires two payments, each equal to half of your previous year's tax bill. The first is due on 31 January (during the tax year) and the second on 31 July (after the tax year ends). Any remaining balance is settled with your Self Assessment return.
What expenses can I deduct as a sole trader?
You can deduct allowable business expenses including office costs, travel, clothing (uniforms), staff costs, stock and materials, financial costs (bank charges, insurance), business premises costs, advertising, and training courses related to your business. The expense must be wholly and exclusively for business purposes.
Sources
Related Calculators
Self-Employed Deduction Wizard
Occupation-aware allowable expenses checklist with simplified mileage, use-of-home flat rates, and trading allowance comparison.
Self Assessment Payment on Account Calculator
Work out your 31 January and 31 July POAs, claim a reduction via SA303, and model late-payment interest and penalties.
National Insurance Calculator
Class 1, 2 & 4 NI for employed and self-employed.
Learn More
UK Self-Employment Tax 2025-26 & 2026-27 — Class 2 & Class 4 NI (HMRC)
HMRC self-employment tax for 2025-26 and 2026-27: voluntary Class 2 (£3.50/wk 2025-26, £3.65 2026-27), Class 4 at 6% (£12,570–£50,270) and 2% above, plus income tax. Payments on account and registration.
Making Tax Digital for Income Tax: What You Need to Know for April 2026
Making Tax Digital for Income Tax Self Assessment (MTD ITSA) launches in April 2026 for sole traders and landlords earning over £50,000. Find out what quarterly reporting means for you and how to get ready.
Self Assessment Deadlines for the 2025-26 Tax Year
Everything you need to know about Self Assessment deadlines for the 2025-26 tax year, including the 31 January 2027 online filing deadline, late filing penalties, and payment on account rules.