Self-Employed Tax Calculator (UK, 2026/27)

Annual gross income / profit before expenses (£)

Annual business expenses (£)

Region

Student Loan Plan

Net Take‑Home

£36,388.80 / year

£3,032.40 / month

£699.78 / week

Gross income	£50,000
− Expenses	−£5,000
= Taxable profit	£45,000
− Personal Allowance	−£12,570
= Taxable income	£32,430
Income Tax: 20% on £32,430	−£6486.00
Total Income Tax	−£6486.00
Class 4 NI: 6% on £32,430	−£1945.80
Total Class 4 NI	−£1945.80
Class 2 NI (flat)	−£179.40
Net take‑home	£36388.80

You may need to make Payments on Account — two advance payments toward your next year’s tax bill, each roughly half this year’s bill, due 31 January and 31 July. This is not tax advice; please check with HMRC.

How your tax is calculated

As a self‑employed person in the UK, you pay Income Tax and National Insurance on your taxable profit — that’s your gross income minus allowable business expenses. This calculator uses the rates for the 2026/27 tax year.

Personal Allowance

This is the amount you can earn before paying Income Tax. For most people it’s £12,570, but it starts to shrink once your profit exceeds £100,000, losing £1 for every £2 of profit over that threshold. By £125,140 the allowance is £0. This taper is the same in Scotland and the rest of the UK.

Scotland

Scotland has its own Income Tax bands (Starter 19%, Basic 20%, Intermediate 21%, Higher 42%, Advanced 45%, Top 48%), while the rest of the UK uses 20%, 40% and 45%. National Insurance, however, is not devolved, so every self‑employed person faces the same Class 4 (6% on profits between £12,570 and £50,270, then 2% above) and Class 2 (flat £179.40 if profits are £6,845 or more).

Payments on Account

These are advance instalments of your next year’s tax bill. HMRC expects you to make two payments (by 31 January and 31 July), each equal to half your previous year’s Income Tax and Class 4 NI. This is why the warning banner appears if your combined bill exceeds £1,000. The final balancing payment is due the following 31 January.

This is a planning estimate only, not a tax return. Tax rules can change every April, and individual circumstances vary. Always check with HMRC or a qualified accountant.

Frequently Asked Questions

What’s the difference between Income Tax and National Insurance?

Income Tax is paid on your taxable income (profit minus Personal Allowance) and funds general government spending. National Insurance is specifically for the NHS, state pension, and other social security benefits. Self‑employed people pay Class 2 (a flat weekly amount) and Class 4 (a percentage of profits). Unlike employees, you don’t pay a separate employer contribution.

Do I need to pay tax quarterly?

No — your annual Self Assessment return is due by 31 January after the tax year ends. However, if your Income Tax and Class 4 NI bill exceeds £1,000, HMRC will usually ask you to make Payments on Account: two advance instalments (each half your previous year’s bill) due on 31 January and 31 July. This is not quarterly but twice a year.

What if I’m on more than one student loan plan?

This calculator assumes you have only one student loan plan (the one you select). In reality, some people have an undergraduate loan (Plan 1, 2, 4 or 5) and a separate postgraduate loan. If that applies to you, you would repay 9% of your profit above the undergraduate threshold plus 6% above the postgraduate threshold. The tool does not combine them — see a specialist calculator or accountant for your exact situation.