UK Income Tax Calculator (Self-Employed) 2024/25–2026/27
Estimate income tax and Class 4 National Insurance on your self-employed profits, using current HMRC rates for England, Wales and Northern Ireland.
Income Tax Calculator (Self-Employed)
What is the Income Tax Calculator (Self-Employed)?
Self-employed UK income tax is the tax you pay on your sole-trader profits after the personal allowance, plus Class 4 National Insurance for 2026/27 (6% between £12,570 and £50,270, then 2% above). You also pay Class 2 NI as a flat weekly amount only if voluntary.
Last reviewed: against HMRC rates for 2024/25 & 2025/26.
Self-employed income tax & Class 4 NI — 2026/27
Worked example
Self-employed profit of £40,000 in 2025/26: £5,486 income tax + £1,646 Class 4 NI = £7,132 due — keep £32,868.
Frequently asked questions
+How much income tax will I pay as self-employed?
Subtract the £12,570 personal allowance from your annual profit, then apply 20% on the next £37,700, 40% up to £125,140, and 45% above. Add Class 4 NI of 6% (then 2% above £50,270) on profits above £12,570.
+What is the trading allowance?
£1,000 of self-employed income is tax-free under the trading allowance. If your gross self-employed income is £1,000 or less, you don't even need to register for Self Assessment.
+Do sole traders pay both Class 2 and Class 4 NI in 2025/26?
Class 2 NI is no longer compulsory. You can pay it voluntarily (£3.45/week in 2025/26) to protect state-pension entitlement. Class 4 NI remains: 6% on profits £12,570–£50,270 and 2% above.
+Can I deduct expenses?
Yes. Allowable business expenses (travel, equipment, home-office, professional fees) are subtracted from your gross income to give the taxable profit used in this calculator.
+When do I pay self-employed tax?
Through Self Assessment — balancing payment on 31 January after the tax year ends, plus payments on account on 31 January and 31 July if your bill exceeds £1,000.