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Self-employed tax calculator for 2026-27

Put in what you took and what you spent, and your wages if you also have a job. You’ll see an estimate of your Income Tax, your Class 4 National Insurance, what you keep and what payments on account could look like. It uses the 2026-27 rates for England, Wales and Northern Ireland, or Scotland’s if you tick the box.

Worked examples (2026-27)

Each row assumes self-employment is the person’s only income and uses the 2026-27 rates for England, Wales and Northern Ireland.

ExampleTurnoverCostsIncome TaxClass 4You keepEffective rate
Part-time handyman £18,000£3,000 £486£145.80 £14,368.204.21%
Plumber, van and tools £45,000£9,000 £4,686£1,405.80 £29,908.2016.92%
Electrician, busy year £75,000£12,000 £12,632£2,516.60 £47,851.4024.05%
Builder over £100,000 profit £140,000£25,000 £36,432£3,556.60 £75,011.4034.77%

How the estimate works

  1. Profit = turnover minus business costs (or minus the £1,000 trading allowance, if you tick that box).
  2. Income Tax on profit above your Personal Allowance (£12,570 in 2026-27, reduced by £1 for every £2 of income over £100,000), at 20%, 40% and 45%. If you enter wages from a job, Income Tax is worked out on wages and profit together, then the tax on the wages alone is taken off because your employer collects that through PAYE. What’s left is the tax your profit adds.
  3. Class 4 National Insurance at 6% between £12,570 and £50,270, and 2% above. For National Insurance on its own, with Class 2, use the self-employed National Insurance calculator.
  4. What you keep = turnover minus the costs you actually paid, minus Income Tax and Class 4 (even if you use the trading allowance for tax). The effective rate is the tax and National Insurance on your self-employment as a share of your profit (not of your wages).
  5. Payments on account: if your bill is £1,000 or more, HMRC usually asks for two advance payments towards next year, each half of this year’s bill after any CIS deductions, due 31 January and 31 July. There are none if more than 80% of your tax was taken at source.
  6. CIS deductions you enter are taken off the bill; if they come to more than the bill, the difference is a refund.

If you live in Scotland, tick the box and Income Tax uses the Scottish bands for 2025-26 and 2026-27. Class 4 National Insurance is the same everywhere in the UK. See tax for self-employed trades in Scotland.

Questions people ask

How much tax does a self-employed person pay in 2026-27?

Outside Scotland, Income Tax is 20% on profit above the £12,570 Personal Allowance up to £50,270, 40% above that and 45% above £125,140. Class 4 National Insurance is 6% on profit between £12,570 and £50,270, and 2% above.

What happens to the Personal Allowance over £100,000?

It goes down by £1 for every £2 of income over £100,000, so the £12,570 allowance is gone completely at £125,140. This calculator takes that into account.

What are payments on account?

Two payments on account, each usually half of last year's bill, are due by 31 January and 31 July unless last year's bill was under £1,000 or more than 80% was collected at source.

Do I need to pay Class 2 National Insurance?

For 2026-27 Class 2 is treated as paid for profits at or above the £7,105 small profits threshold; below it, Class 2 is voluntary at £3.65 a week.

Does this work if I live in Scotland?

Yes, for 2025-26 and 2026-27: tick “I live in Scotland” and Income Tax uses the Scottish bands and rates. Class 4 National Insurance is the same across the UK. For other years the estimate uses the rates for England, Wales and Northern Ireland.

I have a job as well. Does this work?

Yes. Put your wages before tax for the year in “Wages from a job”, from your P60 or last payslip (add them together if you have more than one job). Income Tax is then worked out on your wages and profit together, so your profit is taxed at the rate that applies once it sits on top of your wages, which can push some of it into the 40% band. Over £100,000 the Personal Allowance shrinks on the total. Your employer takes the tax on your wages through PAYE, so the bill shown is the extra your self-employment adds. Class 4 National Insurance is on your profit only, and because you also pay Class 1 on your wages, HMRC caps your Class 4 at an annual maximum. The calculator applies that cap, working out your Class 1 from your yearly pay at the standard employee rate.

What doesn’t this estimate include?

Other income such as rent, savings or dividends, a tax code that collects tax on something else, the exact Class 1 National Insurance you paid (the Class 4 cap here estimates it from your yearly pay), Scottish Income Tax rates for years other than 2025-26 and 2026-27, student loan repayments, pension contributions, losses from earlier years and anything already paid on account. Any of these can change your figure.

This is an estimate based on the figures you entered and the rules for 2026-27. Your actual figure may differ.

What happens next

  1. Keep a running total of what you take and what you spend through the year, so the tax bill is no surprise.
  2. Put some of each payment aside for tax and National Insurance — the effective rate above is a guide to how much.
  3. Or join the Trades Tax waitlist: your books kept from your bank statements, and you confirm every figure before it goes to HMRC.

Sources