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Self-employed tax calculator
Sole trader income tax and Class 4 National Insurance on your 2026/27 profit: what you keep, what to set aside, and what the first 31 January actually costs once payments on account land.
Tax year 2026/27. Assumes a standard tax code on any salary and no other income or reliefs. If you are both employed and self-employed on a high income, annual maximum rules can trim Class 4 slightly.
Yours to keep after tax
£32,868
£2,739 a month · 17.8% of your income goes to tax, NI and loans
- Income tax£5,486
- Class 4 National Insurance£1,646
- Self Assessment bill£7,132
Set aside about £18 of every £100 of profit and the bill will never catch you short.
Your first year of payments
- 31 January (year-one bill + first instalment)£10,698
- 31 July (second instalment)£3,566
Payments on account are advance instalments for next year, each half of this year's tax and Class 4. That makes the first 31 January roughly one and a half bills at once.
Class 2 is covered for free: profits over £7,105 protect your State Pension record without paying anything.
Employed too, or thinking about a limited company? Take-home pay calculator and dividend tax calculator.
Common questions
- How much should I set aside for tax per £100 of profit?
- It depends on your profit level, because tax is tiered. On £30,000 of profit the bill is about £4,532 (£3,486 income tax plus £1,046 Class 4 NI), so roughly £15 of every £100. On £60,000 it is about £13,889, closer to £23 per £100. Many sole traders simply move 25% to 30% of everything they invoice into a separate account; anything left over after the bill is a bonus.
- What are payments on account?
- Advance instalments towards next year's tax, due 31 January and 31 July, each half of this year's income tax and Class 4 bill. They apply once your Self Assessment bill reaches £1,000, unless 80% or more of your tax is collected at source. The sting is year one: on a £30,000 profit your first 31 January asks for the whole £4,532 bill plus a £2,266 first instalment, about £6,798 at once, then £2,266 more in July.
- Do I still pay Class 2 National Insurance?
- Usually not. Since April 2024 Class 2 is no longer compulsory: with profits of £7,105 or more your State Pension record is credited automatically for free. Below £7,105 you get no automatic credit, but you can pay voluntary Class 2 at £3.65 a week (£189.80 a year) to protect your pension and certain benefits. That is one of the cheapest ways to buy a qualifying year.
- How does self-employed NI compare with employee NI?
- Favourably. Employees pay Class 1 at 8% on earnings between £12,570 and £50,270; sole traders pay Class 4 at 6% on the same band. On £30,000 that is £1,394 as an employee but £1,046 as a sole trader, about £349 less. Both pay 2% above £50,270. The trade-off: no employer pension contributions, sick pay or holiday pay.
- Does this work for Scotland?
- Yes. Tick the Scottish income tax box and the calculation switches to Scotland's six bands, which start at 19% and reach 48%. National Insurance and student loan thresholds are the same UK-wide, so only the income tax part changes.
- Is this exact?
- It is a solid estimate for a sole trader with a standard tax code and no other income. Partnership shares, property income, the trading allowance, pension contributions or Gift Aid will change the picture, and if you are employed and self-employed on a high income, annual maximum rules can trim Class 4. It is guidance, not regulated financial advice.
Employed as well, or weighing up a limited company? The take-home pay calculator covers the PAYE side, and the dividend tax calculator shows what a salary-plus-dividends setup would pay instead.