UK self-employed tax calculator 2026/27

How much to set aside as a sole trader: Income Tax, Class 4 National Insurance, a student loan if you have one, and what you pay on 31 January and 31 July.

Tax and National Insurance to pay

£4,531.80

15.1% of your profit · set aside £377.65 a month

Income Tax £3,486
Class 4 NI £1,046
£74 kept of each £100 more

On a profit of £30,000.00, you pay £3,486.00 of Income Tax and £1,045.80 of Class 4 National Insurance: £4,531.80 in all, which is 15.1% of your profit. That leaves £25,468.20 for the year.

You pay through Self Assessment. In your first year you pay the whole bill and the first payment on account by 31 January: £6,797.70, then £2,265.90 by 31 July. After that the bill is settled by a balancing payment on 31 January, with the next payment on account. Each payment on account is half of the Income Tax and Class 4 of the year before (£2,265.90).

Not included: other income, such as a job or rent, the trading allowance of £1,000, pension contributions, losses carried forward and Making Tax Digital rules. They change the result.
This is an estimate for the tax year 2026/27 (6 April 2026 to 5 April 2027). Your return is the record that counts.

I’m not an accountant or a financial advisor. This is an estimate, for information only. Check with a professional before you decide.

Your numbers

example: change the numbers

Your profit for the tax year

Your self-employed income minus your allowable business expenses, for the tax year from 6 April to 5 April. This is the figure on your Self Assessment return, not your turnover.

Where you live and pay tax

Scotland has its own Income Tax bands; England, Wales and Northern Ireland use the same ones. National Insurance is the same everywhere.

England, Wales or Northern Ireland20%, 40%, 45%Scotlandsix bands, 19% to 48%

Student loan

Pick your plan from your loan statement. Plan 1: started before September 2012 in England or Wales, or any time in Northern Ireland. Plan 2: England or Wales from September 2012 to July 2023. Plan 4: Scotland. Plan 5: England from August 2023. The repayment goes on your Self Assessment.

I also repay a Postgraduate Loan

A separate loan for a master’s or doctoral course: 6% of what you earn above £21,000 a year.

YesNo

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The calculation
	Profit	£30,000.00
	Personal Allowancetax-free	£12,570.00
=	Taxable income	£17,430.00
	20% on £17,430	£3,486.00
=	Income Tax	£3,486.00
+	Class 4 National Insurance6% from £12,570 to £50,270, 2% above	£1,045.80
=	Total to pay	£4,531.80
	Left after tax	£25,468.20

How it works

Take your profit: self-employed income minus allowable expenses. Subtract the Personal Allowance of £12,570 (lower if your income is over £100,000) and apply the Income Tax bands: 20%, 40% and 45%, or the six Scottish bands.
Add Class 4 National Insurance: 6% on profits between £12,570 and £50,270 and 2% above. At £7,105 of profit or more Class 2 is treated as paid, so you pay nothing for it.
Add any student loan repayment: 9% of income over the threshold for your plan (6% over £21,000 for a Postgraduate Loan). Your total is paid on 31 January, together with the first payment on account for the next year.

Worked example

A sole trader in England with a profit of £30,000: taxable income £17,430; Income Tax £3,486; Class 4 6% of £17,430 = £1,045.80; total £4,531.80. In the first year: £6,797.70 on 31 January (the bill plus the first payment on account of £2,265.90) and £2,265.90 on 31 July.

Sources

Text checked on October 12, 2026

Good to know

Profit means income minus expenses that are allowable for your business. The more you can legitimately claim, the lower the profit and the tax. Keep records for every expense.
Class 2 National Insurance no longer has to be paid by people with profits of £7,105 or more: it is treated as paid, which keeps your State Pension record. Under that level you can choose to pay it.
Payments on account are two instalments towards next year’s bill, each half of this year’s Income Tax and Class 4. If your profit rises, a balancing payment is due on the next 31 January; if it falls, you can ask to reduce them.
In the first year the tax can feel like a double hit: you pay the whole bill and the first payment on account at the same time, in one January. Setting aside about a quarter of your profit from the start helps.
If you are late with the return or with the money, HMRC charges penalties and interest: £100 for a late return, with daily penalties after 3 months, and 5% of the unpaid tax at 30 days, 6 months and 12 months.
Tell HMRC by 5 October after the end of the tax year if you need to complete a tax return for the first time.

Frequently asked questions

How much tax do I pay on £30,000 of self-employed profit?

In England, £3,486 of Income Tax and £1,045.80 of Class 4 National Insurance: £4,531.80 in all, about 15% of the profit.

What is Class 4 National Insurance for the self-employed?

A contribution on your profits: 6% on the part between £12,570 and £50,270 and 2% above that, for 2026/27. You pay it with your Self Assessment.

Do I still pay Class 2 National Insurance?

Not if your profits are £7,105 or more: it is treated as paid. Below that you can pay it voluntarily at £3.65 a week to protect your State Pension record.

What are payments on account?

Two payments towards next year’s tax bill, due on 31 January and 31 July, each half of your last bill (Income Tax and Class 4). You do not make them if your last bill was under £1,000 or if you paid over 80% of it elsewhere.

When do I pay my Self Assessment bill?

By 31 January after the end of the tax year, which is also the deadline for an online return. If you make payments on account, the second one is due on 31 July.