Self-Employed Tax Calculator UK 2025/26

Estimate the 2025/26 UK Income Tax and Class 4 National Insurance on your self-employment profit, with an optional PAYE salary on top. Scottish taxpayer? Switch region above.

Region: England, Wales & Northern Ireland | Scotland

Last verified against GOV.UK rates: 25 May 2026.

Methodology: this calculator uses the main Income Tax rates for England, Wales and Northern Ireland, the standard Personal Allowance, and self-employed Class 4 National Insurance rates. It does not cover Scottish Income Tax bands, student loans, pension contributions, VAT, benefits, tailored reliefs, or personal tax advice.

Scottish taxpayer? Use the Scottish self-employed tax calculator for the correct starter, basic, intermediate, higher, advanced and top rate bands.

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Tax Calculator

Total earnings from your side hustle before expenses
Enter allowable expenses, or the deduction you want to model, such as the trading allowance
Your main job's yearly salary before any deductions

How this self-employed tax calculator works

Self-employed income is taxed on profit (income minus allowable expenses) through Self Assessment. The calculator stacks self-employment profit on top of any PAYE salary in the same tax year, then estimates the extra Income Tax and Class 4 National Insurance due.

Enter your gross self-employed income, the allowable expenses or £1,000 trading allowance you want to model, and any PAYE salary. The calculator runs entirely in your browser. Nothing about your figures is sent to a server or analytics.

Use it as a self-employed income tax calculator for the current tax year, a self-employed NI calculator before a new contract, or a quick sanity check before your Self Assessment return. Scottish taxpayers should use the Scotland version because Scottish Income Tax bands differ from the rest of the UK.

These figures apply to England, Wales and Northern Ireland for 2025/26. The Personal Allowance is £12,570, the basic rate is 20% to £50,270, the higher rate is 40% to £125,140, and the additional rate is 45% above that. Scottish taxpayers have different bands — use the Scotland calculator linked from the region toggle.

Trading Allowance vs Actual Expenses

The trading allowance can exempt up to £1,000 of gross trading income. If your gross trading income is £1,000 or less, you may not need to tell HMRC, although some circumstances still require a tax return.

If gross trading income is more than £1,000, you can usually choose between deducting the £1,000 trading allowance or deducting actual allowable expenses. You cannot claim both for the same trade.

Self Assessment registration and deadlines

If you cross the £1,000 trading allowance you normally need to register for Self Assessment by 5 October after the tax year ends, and file online by 31 January after the tax year. See the main Self Assessment registration and deadlines section for the 2025/26 dates and payments-on-account rules.

Official Sources

Worked examples: self-employed tax for 2025/26

Example 1

Full-time self-employed worker with £28,000 of trading income and £3,200 of allowable expenses. Profit of £24,800 sits in the basic-rate band, so the bill is roughly 20% Income Tax above £12,570 plus 6% Class 4 NI on profit above £12,570. Class 2 NI is treated as paid because profits clear the Small Profits Threshold.

Example 2

Side self-employed worker with a £42,000 PAYE salary and £8,000 of profit after expenses. The salary uses most of the basic-rate band, so some self-employed profit crosses into 40% Income Tax. Class 4 NI on the trading profit is charged separately through Self Assessment.

Example 3

Higher-earning self-employed contractor with £75,000 of profit. The first slice is taxed at 20%, the rest at 40% up to £125,140, with Class 4 NI at 6% to £50,270 and 2% above. A Self Assessment bill of this size will normally trigger payments on account for the following year.

FAQs

What does this self-employed tax calculator estimate?

It estimates 2025/26 UK Income Tax and Class 4 National Insurance on self-employed profit, optionally combined with a PAYE salary. It uses rates and thresholds for England, Wales and Northern Ireland. If you are a Scottish taxpayer, use the Scottish self-employed tax calculator linked from the region toggle because Scottish Income Tax bands differ.

How is self-employed tax calculated in the UK?

HMRC taxes self-employed people on profit (income minus allowable expenses). Profit is added to any other taxable income, then taxed through Self Assessment at the same Income Tax rates as employment income, plus Class 4 National Insurance on profit above the lower limit. For 2025/26 Class 4 NI is 6% between £12,570 and £50,270, and 2% above £50,270.

Do self-employed people still pay Class 2 National Insurance?

From April 2024 onwards, self-employed people with profits at or above the Small Profits Threshold (£6,725 for 2024/25, £6,845 for 2025/26) are treated as having paid Class 2 NI without any cash payment, which still builds State Pension entitlement. Below that threshold you can pay voluntary Class 2 NI to protect your contributions record.

Which expenses can self-employed workers claim?

You can deduct costs that are wholly and exclusively for the business — for example stock, materials, business travel and mileage, software and subscriptions, professional fees, business insurance, and a proportion of home and phone costs where used for work. Personal-use elements should be excluded or apportioned.

When do payments on account apply?

Payments on account apply when your Self Assessment bill is at least £1,000 and less than 80% of your tax was collected through PAYE or other means. HMRC asks for two equal payments toward the following year's bill, due 31 January and 31 July, each one half of the previous year's Self Assessment liability.

Should I use the £1,000 trading allowance or actual expenses?

If gross trading income is £1,000 or less, the trading allowance can exempt it entirely. Above £1,000 you can usually choose between deducting the £1,000 trading allowance or deducting your actual allowable expenses. Pick whichever is larger — you cannot claim both for the same trade.