Self-Employed Tax Calculator (UK)
Estimate your income tax and National Insurance on self-employed trading profit for 2026/27, and see what you keep after tax. Enter your profit in our calculator — it handles the Personal Allowance, Income Tax bands and Class 4 NI.
How Self-Employed Tax Works
Three things determine your bill: the Personal Allowance, Income Tax bands, and National Insurance.
| Component | 2026/27 (England) |
|---|---|
| Personal Allowance | £12,570 (withdrawn above £100k) |
| Income Tax | 20% to £50,270 · 40% to £125,140 · 45% above |
| Class 4 NI | 6% (£12,570–£50,270) · 2% above |
| Class 2 NI | Abolished from April 2024 (voluntary only) |
Self-Employed Tax Tips
- Allowable expenses: office, travel, software, accountancy fees all reduce profit.
- Payments on account: budget ~50% of your tax bill twice a year to avoid a January shock.
- Pension: personal pension contributions extend your basic-rate band, cutting higher-rate tax.
- Marriage Allowance: if your partner is a non-taxpayer you can transfer allowance.
Frequently asked questions
How is self-employed tax calculated in the UK?
You pay Income Tax on your trading profit (turnover minus allowable expenses) after the Personal Allowance, plus Class 4 National Insurance on profits above £12,570. Class 2 NI was abolished in April 2024, so most sole traders no longer pay it (voluntary contributions can still fill gaps). Payments are made via Self Assessment in two instalments.
What NI do the self-employed pay?
Class 4 NI is 6% on profits between £12,570 and £50,270 and 2% above that. Class 2 NI was abolished from 6 April 2024; only voluntary contributions remain available to protect your NI record.
When do I pay self-employed tax?
Through Self Assessment: a payment on account by 31 January and a second by 31 July, with the balancing payment the following January. Use our calculator to estimate the annual bill, then budget monthly.