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Calculator 01 · 2026/27 tax year

Sole Trader Tax Calculator.

Enter your annual self-employment profit (your turnover minus your allowable business expenses). The calculator works out your income tax and Class 4 National Insurance, and shows the full breakdown by tax band.

Your profit

£
Your turnover minus your allowable business expenses, for the tax year 6 April 2026 to 5 April 2027.
This is for sole traders and partners only. If you also have employment (PAYE) income, dividends, rental income, savings interest or capital gains, they stack on top of self-employment profit — book a free call to get the full picture.

Your tax

Personal allowance used£0
Income tax£0
Class 4 National Insurance£0
Total tax£0
Take-home (after tax)£0
Effective tax rate0%
Marginal rate on next £10%

Want help planning around this number? Book a free 20-minute call with Fahmina.

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How this is calculated

Personal allowance (PA): the first £12,570 of profit is tax-free (the standard personal allowance for 2026/27). If your profit is over £100,000, your PA reduces by £1 for every £2 over £100,000 — fully tapered at £125,140.

Income tax bands (England, Wales, Northern Ireland — 2026/27)

Basic rate 20%: profit between £12,571 and £50,270 (the band size is £37,700).
Higher rate 40%: profit between £50,271 and £125,140 (£74,870 band).
Additional rate 45%: profit above £125,140.

Note: from April 2027 these rates rise — basic 20→22%, higher 40→42%, additional 45→47%. The April 2026 dividend rate hike is already reflected in our Dividend Calculator.

Class 4 National Insurance (2026/27)

6% on profit between £12,570 and £50,270.
2% on profit above £50,270.

Class 2 NIC was abolished for self-employed people from 6 April 2024 — you don't pay Class 2 automatically anymore. There's a voluntary £17.75/week rate available for those with profits below the Small Profits Threshold (£6,725) who want to build State Pension entitlement, but it's optional and not included in this calculator.

Want this calculated properly?

Calculators handle straightforward sole-trader situations. But pension contributions, Marriage Allowance, the £100k personal allowance taper, Gift Aid, payments on account, and any other income source all change the picture. We do this for £45/month including the actual return filing.

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Common questions

What does this calculator include?

Income tax (basic 20%, higher 40%, additional 45% — 2026/27 rates for England, Wales and Northern Ireland) and Class 4 National Insurance (6% on profit £12,570 to £50,270, 2% above). It assumes the standard £12,570 personal allowance and includes personal allowance tapering between £100,000 and £125,140.

Why isn't Class 2 NIC included?

Class 2 NIC was abolished for self-employed people from 6 April 2024. There's a voluntary Class 2 rate (£17.75/week in 2026/27) for those with profits below the Small Profits Threshold who want to build State Pension credit — but it's not automatic and the calculator correctly ignores it.

Does this calculator handle Scottish income tax?

No. The bands used apply to England, Wales and Northern Ireland. Scotland has different bands. If you're a Scottish taxpayer, the income tax figure will be approximate — Class 4 NIC is the same UK-wide.

What if I have other income like employment or dividends?

This calculator works on self-employment profit alone. If you also have employment income (PAYE), rental income, dividends, savings interest or capital gains, these all stack and may push you into higher bands. For mixed income, book a free 20-minute call and we'll work through your specific position.

What about payments on account?

If your tax bill is over £1,000, HMRC asks for two payments on account toward next year's bill — due 31 January and 31 July. The calculator shows your total tax for the year; the payments on account are 50% each of that total, due in advance. See our Payment on Account guide for details.