taxnoob

UK Sole Trader Calculator

Estimate your net income as a self-employed IT contractor (sole trader)

£

Allowable costs: equipment, software, professional fees, home office, travel.

Repaid via Self Assessment alongside tax and NI.

ℹ️ Calculation based on HMRC Sole Trader rules (not limited company). Does not include Class 2 NI (abolished April 2024).
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Enter your rate to see results

Common Questions

As a self-employed sole trader you pay three main taxes via Self Assessment:

•Income Tax — on your taxable profit (revenue minus expenses), above the Personal Allowance.
•NI Class 4 — National Insurance at 6% on profit between £12,570–£50,270, then 2% above. (Class 2 was abolished in April 2024.)
•VAT — if your turnover exceeds £90,000 and your clients are in the UK. For B2B services to non-UK clients, VAT is 0% (outside scope).

You file a Self Assessment return by 31 January each year and make two Payments on Account (50% advance in July and January).

The Personal Allowance is £12,570 — a tax-free band applied to everyone's income, regardless of whether they're employed or self-employed.

For a sole trader, it reduces your taxable income: if you earn £50,000 profit, only £37,430 (£50,000 − £12,570) is subject to Income Tax.

Important caveat: if your profit exceeds £100,000, the Personal Allowance is tapered at £1 for every £2 above £100,000. It reaches £0 at £125,140. This creates an effective 60% marginal rate in the £100k–£125.14k band — arguably the highest in the UK tax system.

It depends on two things: your annual turnover and where your clients are.

If your UK client-facing turnover stays below £90,000, you do not need to register for VAT. Many sole traders voluntarily register anyway to reclaim input VAT on purchases.

If your clients are outside the UK (US, EU, etc.), your services are outside the scope of UK VAT — you do not charge VAT regardless of your turnover. This is common for IT contractors working for international companies.

Once you're VAT-registered and exceed the threshold with UK clients, you must charge 20% VAT on all UK sales and file quarterly returns.

Scotland has its own income tax rates set by the Scottish Parliament, funded by the Scotland Act 2016. There are 6 bands compared to 3 for the rest of the UK:

•Starter rate: 19% (up to ~£15,397–£16,537 depending on year)
•Basic rate: 20% (up to ~£27,491–£29,526)
•Intermediate rate: 21% (up to £43,662)
•Higher rate: 42% (up to £75,000)
•Advanced rate: 45% (up to £125,140)
•Top rate: 48% (above £125,140)

Key point: NI Class 4 is the same across all UK nations — only Income Tax differs in Scotland.

The 60% trap is a quirk of the Personal Allowance taper. Between £100,000–£125,140:

•For every £2 you earn above £100,000, your Personal Allowance falls by £1.
•That £1 of previously tax-free income becomes subject to 40% Higher Rate tax.
•Plus the new £2 of income is also taxed at 40%.
•Combined: 40% on the new income + 40% on the lost PA income = 60% effective marginal rate.

At £125,140 the PA reaches £0 and you re-enter the normal 40% band. Many accountants recommend contributing to a pension to reduce profit below £100,000 and escape this trap.