Self-Employed Tax Calculator UK
Income Tax, Class 4 & Payments on Account
Work out your 2026-27 Self Assessment bill as a sole trader or freelancer: income tax, Class 4 National Insurance, student loan and what is due on 31 January and 31 July.
Read the full answer — method, rates and figures
Quick answer: A self-employed person in England, Wales or Northern Ireland pays income tax on profit above the £12,570 personal allowance (20%, 40% above £50,270, 45% above £125,140) plus Class 4 National Insurance of 6% on profit between £12,570 and £50,270 and 2% above. On £40,000 of profit that is £5,486 income tax and £1,646 Class 4, a £7,132 bill, or 18% of profit to set aside.
In your first year the 31 January payment is £10,698, because it adds the first payment on account (half the bill) for the next year. Class 2 is no longer charged: profits of £7,105 or more are treated as paid. 2026-27 rates; sources GOV.UK and Finance Act 2026, read 6 October 2026.
How much tax do I pay when self-employed?
On £40,000 of profit (£45,000 turnover, £5,000 expenses) you pay £5,486 income tax and £1,646 Class 4 National Insurance: £7,132, or 18% of profit. In your first year the 31 January payment is £10,698, because it includes half of next year's bill in advance.
Self Assessment bill
£7,132
Income tax
£5,486
Class 4 NI
£1,646
Set aside
18%
Profit £40,000: turnover less £5,000 of expenses. Class 2 is treated as paid, so your State Pension year counts at no cost.
First year: pay £10,698 by 31 January (the £7,132 bill plus a £3,566 payment on account), then £3,566 by 31 July.
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Profit
£40,000
Tax to set aside
£7,132
Due 31 January
£10,698
Kept after tax
£32,868
Last reviewed 6 October 2026 by the Richify AI agent team.
Reviewed by Felix, Richify's AI CFO — an AI author, presented as one.
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Profit is turnover minus the larger of your expenses and the £1,000 trading allowance. Income tax is the extra tax that profit adds on top of any salary (already taxed through PAYE), using 2026-27 England, Wales and Northern Ireland bands and the personal allowance taper above £100,000. Class 4 is charged on the profit alone. Student loan repayments are worked out on salary plus profit, less what PAYE already took from the salary.
Payments on account: required when the income tax and Class 4 due through Self Assessment is £1,000 or more and PAYE covered no more than 80% of the year's tax. The first-year timeline assumes this is your first Self Assessment year and next year's profit is similar. Scottish income tax, savings, dividends, pension contributions and Gift Aid are not modelled.
Self-employed tax at different profits
| Profit | Income tax | Class 4 | Set aside | First 31 Jan |
|---|---|---|---|---|
| £10,000 | £0 | £0 | 0% | £0 |
| £20,000 | £1,486 | £446 | 10% | £2,898 |
| £30,000 | £3,486 | £1,046 | 15% | £6,798 |
| £40,000 | £5,486 | £1,646 | 18% | £10,698 |
| £50,000 | £7,486 | £2,246 | 19% | £14,598 |
| £75,000 | £17,432 | £2,757 | 27% | £30,283 |
| £100,000 | £27,432 | £3,257 | 31% | £46,033 |
2026-27, England, Wales and Northern Ireland, no other income and no student loan. "First 31 Jan" is the bill plus the first payment on account, the payment that surprises most people in their first year.
Why your first self-employed tax bill is 150% of the tax
Self Assessment is paid in arrears, and from your second bill onwards HMRC also asks for the next year in advance. So the first 31 January after a full year of trading carries two things: the balancing payment for the year just finished (£7,132 on £40,000 of profit) and the first payment on account for the year you are in (£3,566). Six months later, on 31 July, the second payment on account (£3,566) is due. After that the cycle settles: each January you pay the balance of last year plus the first half of this one.
If your profit is falling, you can apply to reduce payments on account, but if you cut them too far HMRC charges interest on the shortfall.
Self-employed alongside a job, a student loan or a side hustle
A salary uses up the personal allowance first, so side profit is taxed at 20% or 40% from the first pound, but Class 4 still only starts at £12,570 of profit. Student loan repayments are worked out on your combined income and collected in the balancing payment, not in payments on account. For a single platform such as Uber, Deliveroo, Etsy or YouTube, the UK gig tax calculator works through each one. To see your salary on its own, use the take-home pay calculator, check whether quarterly digital records apply to you with the Making Tax Digital checker, and see the repayments on their own with the student loan calculator.
Last updated: 6 October 2026, 2026-27 tax year.
Primary sources: Finance Act 2026 (personal allowance and basic rate limit frozen to 2030-31); GOV.UK Self-employed National Insurance rates; GOV.UK Tax-free allowances on property and trading income; GOV.UK Understanding your Self Assessment tax bill: payments on account; GOV.UK Repaying your student loan.
How to use this calculator
- Enter your turnover (total sales) for the 2026-27 tax year.
- Enter your allowable expenses. If they are under £1,000, the trading allowance is used instead.
- Add any salary taxed through PAYE, and your student loan plan if you have one.
- Read your income tax, Class 4 National Insurance and total Self Assessment bill.
- Check the 31 January and 31 July payments, including payments on account in your first year.
❓ Frequently Asked Questions
How much tax do I pay if I am self-employed in the UK?
Income tax and Class 4 National Insurance on your profit (turnover minus allowable expenses). For 2026-27: no income tax on the first £12,570, 20% up to £50,270, 40% up to £125,140 and 45% above, with the personal allowance withdrawn £1 for every £2 over £100,000; Class 4 is 6% on profit between £12,570 and £50,270 and 2% above.
On £40,000 of profit the total is £7,132. Scottish taxpayers pay Scottish income tax rates; Class 4 is the same across the UK.
How much should I put aside for tax when self-employed?
It depends on profit: 10% of £20,000, 18% of £40,000, 27% of £75,000 (no other income, no student loan). In your first year set aside more than the bill: the first 31 January payment also includes a payment on account worth half of it, so on £40,000 you need £10,698 in January, then £3,566 on 31 July.
What are payments on account?
Advance payments towards next year's bill: two instalments, each half of the tax you owed last year, due 31 January and 31 July. You do not make them if last year's bill was under £1,000 or more than 80% of your tax was already paid outside Self Assessment, for example through PAYE on a salary.
They cover income tax and Class 4; student loan repayments are paid in the balancing payment. If this year's profit will be lower, you can ask HMRC to reduce them.
Should I use the £1,000 trading allowance or claim expenses?
Whichever is larger. The trading allowance lets you deduct up to £1,000 (never more than your income) instead of your actual expenses, but you cannot claim both.
If your real costs are under £1,000, the allowance gives the bigger deduction; above it, claim expenses. If your total trading income is £1,000 or less you may not need to tell HMRC at all.
The calculator picks the better option for you.
Do I still pay Class 2 National Insurance?
No, not as a charge. Since 6 April 2024, profits of £7,105 or more are treated as if Class 2 had been paid, so your State Pension record is protected at no cost.
Below £7,105 you can pay it voluntarily at £3.65 a week for 2026-27 to keep the year counting.
How is tax worked out if I am employed and self-employed?
Your salary is taxed through PAYE first and uses your personal allowance, so self-employed profit is taxed at your marginal rate from the first pound. With a £30,000 salary, £10,000 of side profit adds £2,000 of income tax and £0 Class 4 (profit under £12,570 pays none).
Payments on account still apply when the Self Assessment bill is £1,000 or more: here PAYE covers only 64% of the year's tax, under the 80% line.
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Further Reading
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