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Self-employed tax calculator

Self-employed people pay Income Tax on their profit at the same rates as employees, plus Class 4 National Insurance of 6% between £12,570 and £50,270. On £30,000 of profit in 2025/26 that comes to £4,532, due by 31 January 2027. Enter your figures for the exact bill, your payments on account and what to set aside.

By Dominic Roworth · Rates checked 1 November 2026 against GOV.UK and HMRC

Everything the business earned (turnover), before expenses.

Taxed through PAYE with tax code 1257L; we show only the extra tax your profit adds.

Your tax bill

£4,531.80

15.1% of your £30,000 profit

Income Tax£3,486.00
Class 4 National Insurance£1,045.80

You keep £25,468.20 of your profit, about £2,122 a month.

Self-employed tax rates for 2025/26 and 2026/27

The figures that set a sole trader's bill. Income Tax bands are the same in both years: the government has frozen the thresholds. Scotland's starter and basic rate bands rose in 2026/27.

2025/262026/27Source
Personal Allowance£12,570£12,570GOV.UK
Basic rate 20% (England, Wales, NI) up to£50,270£50,270GOV.UK
Higher rate 40% up to, then 45%£125,140£125,140GOV.UK
Personal Allowance starts to shrink at£100,000£100,000GOV.UK
Class 4 NI: 6% on profits from£12,570£12,570HMRC
Class 4 NI: 2% on profits above£50,270£50,270HMRC
Small Profits Threshold (NI credit without paying)£6,845£7,105HMRC
Voluntary Class 2, a week£3.50£3.65HMRC
Trading allowance£1,000£1,000GOV.UK

How much tax on your profit

For a sole trader with no other income, no student loan and no pension contributions:

ProfitTax and NI 2025/26You keep2026/27In Scotland, 2025/26
£15,000 £632 (4.2%) £14,368 £632 £608
£20,000 £1,932 (9.7%) £18,068 £1,932 £1,904
£30,000 £4,532 (15.1%) £25,468 £4,532 £4,529
£45,000 £8,432 (18.7%) £36,568 £8,432 £8,860
£60,000 £13,889 (23.1%) £46,111 £13,889 £15,670
£110,000 £36,889 (33.5%) £73,111 £36,889 £40,970

On £30,000: Income Tax is 20% of the £17,430 above the Personal Allowance (£3,486.00), and Class 4 is 6% of the same £17,430 (£1,045.80). In Scotland the Income Tax is £3,482.82: a little less, as the 19% starter rate saves more than the 21% intermediate rate adds at this level; Scottish rates cost more from about £30,400 of income. National Insurance is the same everywhere in the UK. At £110,000 the bill jumps: the Personal Allowance shrinks by £1 for every £2 over £100,000, so income between £100,000 and £125,140 is taxed at an effective 60%.

Payments on account: the January surprise

Your first Self Assessment bill is usually bigger than the tax for the year. As well as the year's tax, HMRC asks for the first payment on account towards next year: half of this year's Income Tax and Class 4. The second half is due on 31 July.

  • First year, £30,000 profit (2025/26): £4,531.80 for 2025/26 plus a first payment on account of £2,265.90, so £6,797.70 by 31 January 2027, then £2,265.90 by 31 July 2027.
  • Later years: the payments you made in advance count against the bill, so in a steady year you pay about half the bill each January and July. If your profit falls, you can ask HMRC to reduce them (form SA303 or in your online account).
  • No payments on account if your Self Assessment bill is £1,000 or less, or more than 80% of your tax was taken at source, for example through PAYE on a salary. Student loan repayments and Class 2 are never included.

Self-employed with a job as well

If you have a salary, PAYE uses your Personal Allowance first, so every pound of profit is taxed at your top rate. On a £35,000 salary with a £12,000 side business and £2,000 of expenses, the £10,000 profit adds £2,000.00 Income Tax. Class 4 is still worked out on the profit alone, so there is none below £12,570: here £0.00. National Insurance on the salary is taken through payroll as usual.

Class 2 National Insurance and your State Pension

Class 2 has not been compulsory since 6 April 2024. With profits of £6,845 or more (2025/26; £7,105 in 2026/27), the year counts towards your State Pension and you pay nothing for it. Below that, you can pay voluntary Class 2 at £3.50 a week through your tax return: £182.00 for the year, far less than Class 3 at £17.75 a week. On £5,500 of profit, for example, there is no Income Tax or Class 4 to pay, but the year only counts if you choose to pay the £182.00.

Student loans

Self Assessment collects student loan repayments on your total income above your plan's threshold: 9%, or 6% for a Postgraduate Loan, less anything PAYE already took from a salary. Thresholds for 2025/26: Plan 1 £26,065, Plan 2 £28,470, Plan 4 £32,745, Postgraduate £21,000. For 2026/27: Plan 1 £26,900, Plan 2 £29,385, Plan 4 £33,795, Plan 5 £25,000, Postgraduate £21,000. On £40,000 profit with a Plan 2 loan, 2025/26 adds £1,037. The repayment is due with the January bill but is not part of payments on account.

Deadlines and penalties for 2025/26

  • 5 October 2026: the date to register for Self Assessment if 2025/26 was your first year.
  • 31 October 2026: paper returns (passed).
  • 30 December 2026: file online by then and, if you also have a PAYE job, HMRC can collect a smaller bill through your tax code over the next year instead of in one go.
  • 31 January 2027: online return and payment of the balance, plus the first payment on account for 2026/27.
  • 31 July 2027: the second payment on account.

A late return costs £100 straight away, then £10 a day after three months (up to £900), then 5% of the tax due or £300, whichever is more, at six and again at twelve months. Tax paid late adds 5% of the unpaid amount at 30 days, six months and twelve months, plus interest at the Bank of England base rate plus 4% (7.75% a year since 9 January 2026).

Making Tax Digital from April 2026

Sole traders and landlords whose qualifying income was over £50,000 in 2024/25 have had to keep digital records and send quarterly updates since 6 April 2026. The threshold falls to £30,000 from 6 April 2027, judged on your 2025/26 return, and to £20,000 from 6 April 2028, judged on 2026/27. Qualifying income is turnover from self-employment plus gross rents, not profit: a sole trader with £35,000 of sales and £10,000 of profit in 2025/26 joins in April 2027. Salaries, dividends and pensions don't count. You still file a final return by 31 January, and the tax works out the same.

What changes from April 2027

The Budget on 28 October 2026 announced, for 2027/28 onwards:

  • Trading allowance up to £3,000 from 6 April 2027, and no need to report trading income of £3,000 or less (HMRC; still to be passed in the Finance Bill).
  • Class 4 unchanged at 6% and 2% between £12,570 and £50,270; the Small Profits Threshold rises to £7,355 and voluntary Class 2 to £3.80 a week (Budget 2026 rates).
  • Income Tax thresholds frozen until April 2031, so the £12,570 allowance and £50,270 higher rate threshold stay.
  • Payments on account to be replaced, from April 2029, by smaller automated payments through the year, after a consultation.

Limits

The calculator is for one sole trade and an optional salary taxed under a standard tax code. It does not include pension contributions, Gift Aid or the Marriage Allowance (which lower the bill), savings, dividend or rental income, partnerships, losses, Capital Gains Tax, the High Income Child Benefit Charge, or the annual maximum that can cap Class 4 for people who also pay Class 1 on a large salary. It is a guide, not tax advice; your Self Assessment calculation from HMRC is the final word.

Questions

How much tax do I pay if I am self-employed in the UK?

Income Tax at the same rates as employees on your profit above the £12,570 Personal Allowance (20% up to £50,270, then 40%), plus Class 4 National Insurance of 6% on profits between £12,570 and £50,270 and 2% above. On £30,000 of profit in 2025/26 that is £3,486 Income Tax and £1,046 National Insurance, £4,532 in all, or 15.1% of the profit.

How much should I put aside for tax when self-employed?

Work out your own figure above, as it depends on your profit. As a guide, a basic-rate taxpayer with no other income keeps back about 20% to 25% of profit, and more in the first year, when the January bill also includes the first payment on account for the next year. On £30,000 profit, the first January bill for 2025/26 would be £6,798, followed by £2,266 on 31 July 2027.

Do I pay Class 2 National Insurance?

Not as a compulsory charge since 6 April 2024. If your profits are £6,845 or more (2025/26), you get a National Insurance credit towards the State Pension without paying. Below that you can choose to pay voluntary Class 2 at £3.50 a week (£182.00 for the year) to fill the gap in your record.

What are payments on account?

Advance payments towards next year's bill, each half of this year's Income Tax and Class 4 National Insurance, due on 31 January and 31 July. You make them unless your Self Assessment bill is £1,000 or less, or more than 80% of your tax was already taken at source (for example through PAYE on a salary). Student loan repayments and Class 2 are never part of them.

Do I need to tell HMRC about a side hustle?

Not if your total trading income (before expenses) is £1,000 or less in the tax year: the trading allowance covers it (it rises to £3,000 from April 2027). Above that you register for Self Assessment by 5 October after the end of the tax year and either deduct your actual expenses or claim the £1,000 allowance instead, whichever leaves less profit. The allowance can't be used for partnership income or work for your own employer.

Related

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