Becoming a sole trader is the simplest way to work for yourself in the UK. There is no company to register, no separate business tax return, and no complex accounts, just you, your profit, and an annual Self Assessment to HMRC. But simple does not mean automatic: you are responsible for calculating your own tax and National Insurance, and for paying it on time.
This guide walks through how a sole trader is taxed in the 2025/26 tax year: the income tax bands, the personal allowance, Class 4 National Insurance, and the Self Assessment deadlines that catch people out. Figures reflect 2025/26 rules and are informational, not personal tax advice.
The UK tax year is unusual: it runs from 6 April to 5 April, not January to December. That quirk matters, because every threshold and deadline in this guide hangs off those dates. Once you internalise the rhythm, earn through the year, file the following winter, pay by 31 January, the rest of the system becomes far less intimidating.
What is a sole trader?
A sole trader is a self-employed individual who runs their business as themselves, there is no legal separation between you and the business. You keep all the profit after tax, but you are also personally liable for any debts.
Compared with a limited company, a sole trader benefits from:
- Minimal paperwork and no Companies House filings.
- Privacy, your accounts are not published.
- A single, straightforward Self Assessment return each year.
The trade-off is unlimited personal liability and, at higher profits, a potentially higher tax bill than an equivalent company. To see your own figures, use our UK sole trader tax calculator.
The two things you pay
As a sole trader you pay two main charges on your profit:
- Income Tax, on profit above your personal allowance.
- Class 4 National Insurance, contributions toward the state pension and benefits.
Both are calculated on your profit, your business income minus allowable expenses, not your total turnover. There is also a small flat-rate Class 2 element for lower earners, though recent reforms mean many sole traders now receive their qualifying year without an explicit Class 2 payment.
This profit-based approach is worth pausing on. If you turn over £60,000 but spend £15,000 running the business, you are taxed on £45,000, not the £60,000 that landed in your account. Keeping clean records of every deductible cost is therefore not just tidy bookkeeping; it directly shrinks the figure HMRC taxes.
Income tax bands for 2025/26
England, Wales and Northern Ireland share the same bands (Scotland sets its own). The personal allowance, the amount you can earn tax-free, is £12,570. Above that, the following rates apply:
| Band | Taxable income | Rate |
|---|---|---|
| Personal allowance | £0 – £12,570 | 0% |
| Basic rate | £12,571 – £50,270 | 20% |
| Higher rate | £50,271 – £125,140 | 40% |
| Additional rate | Over £125,140 | 45% |
One important trap: once your income passes £100,000, your personal allowance is reduced by £1 for every £2 of income, disappearing entirely at £125,140. This creates an effective 60% marginal rate on that slice of income.
Class 4 National Insurance
On top of income tax, sole traders pay Class 4 National Insurance on their profits. For 2025/26 the rates are:
- 0% on profits up to the lower profits limit (£12,570).
- 6% on profits between £12,570 and £50,270.
- 2% on profits above £50,270.
Note that National Insurance and income tax use different logic even where the thresholds line up, so it pays to calculate them separately rather than assuming one rate covers everything.
National Insurance is often misunderstood as "just another tax", but it directly builds your entitlement to the State Pension and certain benefits. Paying enough in a given year secures a "qualifying year" toward your pension record. That is why even low-profit traders may choose to make voluntary contributions, to avoid gaps that would otherwise reduce their future pension.
A full worked example
Consider Priya, a freelance graphic designer in England. After deducting allowable expenses, her profit for 2025/26 is £45,000. Here is how her bill breaks down:
| Step | Calculation | Amount |
|---|---|---|
| Profit | - | £45,000 |
| Personal allowance | tax-free | £12,570 |
| Taxable income | £45,000 − £12,570 | £32,430 |
| Income tax | £32,430 × 20% | £6,486 |
| Class 4 NIC | (£45,000 − £12,570) × 6% | £1,946 |
| Total due | income tax + NIC | £8,432 |
| Take-home profit | £45,000 − £8,432 | £36,568 |
Priya's effective rate is about 19% of profit. Because she stays within the basic-rate band, all of her taxable income is taxed at 20% and her Class 4 NIC stays at the 6% rate. A higher earner would see the 40% and 2% bands kick in on the income above £50,270.
To see how the bands stack at higher profits, imagine Priya grows to £70,000. She would pay 20% on income up to £50,270 and 40% on the slice above it, while her Class 4 NIC would switch from 6% to just 2% once she passes the same £50,270 point. This mix of a rising income-tax rate and a falling NIC rate is a quirk of the UK system that surprises people the first time they cross into the higher band.
Payments on account explained
The single biggest cash-flow shock for new sole traders is payments on account. If your tax bill exceeds £1,000, HMRC assumes next year will be similar and asks you to pay it in advance, in two instalments.
Here is how it bites in year one. Suppose your first bill is £8,000. On 31 January you pay that £8,000 plus a £4,000 payment on account (half of next year's estimated bill), £12,000 in one go. A further £4,000 follows on 31 July. Once you are in the cycle it evens out, but that first January can be brutal if you have not saved for it, which is why setting money aside from day one is essential.
Allowable expenses
You only pay tax on profit, so claiming every legitimate expense directly lowers your bill. HMRC allows costs incurred "wholly and exclusively" for the business, including:
- Office costs, stationery, and phone or internet bills.
- Business travel and mileage.
- A proportion of home costs if you work from home.
- Professional fees, insurance, and marketing.
- Stock and raw materials.
Sole traders can use the trading allowance, a flat £1,000 tax-free, instead of itemising, which suits very small side incomes. If your expenses are below £1,000, claim the allowance; if they are higher, deduct the real costs. If a term is unfamiliar, our tax glossary explains it plainly.
Records matter here too. HMRC can ask you to justify a claim, so keep receipts, invoices and mileage logs for at least five years after the January filing deadline. Cloud accounting software makes this painless and will also matter under Making Tax Digital, discussed below.
Self Assessment deadlines
Sole traders report through Self Assessment. The key dates for the 2025/26 tax year (which runs 6 April 2025 to 5 April 2026) are:
- 5 October 2026, deadline to register if you are newly self-employed.
- 31 October 2026, paper return deadline.
- 31 January 2027, online return deadline and payment of tax owed.
If your bill exceeds £1,000 you will also make payments on account, two advance payments toward next year's tax, due 31 January and 31 July. This effectively front-loads your first big bill, which surprises many new traders. Setting money aside from each invoice smooths the shock; our tax set-aside calculator shows how much to reserve.
VAT: the other threshold
Separate from income tax, you must register for VAT once your turnover passes the registration threshold (£90,000 on a rolling 12-month basis). VAT is charged on your sales and reclaimed on your purchases; it is not a tax on profit, but it adds admin and affects pricing. Many sole traders stay below the threshold deliberately, while others register voluntarily to reclaim input VAT.
Making Tax Digital
Change is coming to how sole traders report. Under Making Tax Digital for Income Tax (MTD for ITSA), self-employed people above certain income levels will need to keep digital records and send HMRC quarterly updates through compatible software, rather than one annual return.
The rollout is phased by income, starting with higher earners and widening over time. If your self-employment income is substantial, it is worth adopting cloud accounting software now so the transition is seamless. Check GOV.UK for the current start date and income threshold that apply to you.
Sole trader vs. limited company
As profits rise, many traders ask whether to incorporate. A limited company pays Corporation Tax and can let owners draw a mix of salary and dividends, which is often more tax-efficient at higher profit levels, but it brings extra filings, accountancy costs, and public accounts. There is no universal answer; the crossover point depends on your profit and how much you withdraw. Comparing across borders too? Our compare taxes by country tool lines up the UK against Italy and the US.
Where the rules come from
UK self-employment tax is administered by HM Revenue & Customs (HMRC). Rates, allowances and thresholds are set in the Budget and published on GOV.UK for each tax year. Because these figures change annually, and Scotland operates its own income tax bands, always confirm the current-year numbers before filing your return. The PwC Worldwide Tax Summaries (2025) offer a useful second reference on UK personal taxation.
Work out your take-home
Tax should never be a January guessing game. Enter your expected profit into our UK sole trader tax calculator to see your income tax, Class 4 National Insurance and take-home pay instantly, then use the tax set-aside calculator to reserve the right amount from each invoice ahead of your 31 January and 31 July deadlines.