Part of the UK Freelancer Tax Hub — the full cluster index.
How much UK Self Assessment tax will I pay this year?
Your 2025/26 UK Self Assessment tax bill is income tax at 20% / 40% / 45% on profit above your £12,570 personal allowance, plus Class 4 NI at 6% (£12,570-£50,270) and 2% above. Enter your profit into the calculator below for a precise figure.
Key takeaways
- Personal allowance for 2025/26 is £12,570
- Basic rate 20% applies to profit £12,571 - £50,270
- Higher rate 40% applies to profit £50,271 - £125,140
- Class 4 NI is 6% on profits £12,570 - £50,270, then 2% above
- Payments on account become due if your bill exceeds £1,000
Editorial: Calculator maintained by the FreelanceToolkit UK editorial team using HMRC's published 2025/26 rates. Worked examples cross-check against HMRC's Self Assessment worksheets. Editorial policy · Sources & methodology · How we test tools.
In this guide
This calculator estimates UK Self Assessment tax and Class 4 National Insurance for sole traders and freelancers at 2025/26 rates. It handles the personal allowance (£12,570), the £100k taper, basic-rate (20%), higher-rate (40%) and additional-rate (45%) bands, and Class 4 NI on profits above £12,570. It doesn't handle Class 2 (now automatically credited if profits exceed £6,725), student-loan repayments, or non-trading income — for those, use HMRC's full Self Assessment portal.
Worked example
Your £45,000 profit sits entirely in the basic-rate band after deducting the £12,570 personal allowance. Income tax: (£45,000 - £12,570) × 20% = £6,486. Class 4 NI: (£45,000 - £12,570) × 6% = £1,946. Total tax + NI: £8,432. Take-home: £36,568. If HMRC required payments on account (they will next January if the total bill exceeds £1,000), you'd owe the £8,432 by 31 January 2027 plus a first payment on account of £4,216, then a second payment on account of £4,216 on 31 July 2027. Setting aside 25-28% per invoice makes January manageable.
At-a-glance comparison
| Profit level | Income tax | Class 4 NI | Total tax + NI | Take-home |
|---|---|---|---|---|
| £20,000 | £1,486 | £446 | £1,932 | £18,068 |
| £35,000 | £4,486 | £1,346 | £5,832 | £29,168 |
| £50,000 | £7,486 | £2,246 | £9,732 | £40,268 |
| £75,000 | £17,432 | £2,721 | £20,153 | £54,847 |
| £100,000 | £27,432 | £3,221 | £30,653 | £69,347 |
| £125,140+ | Personal allowance = £0 | Additional rate 45% kicks in | — | — |
Decision tree
Answer these questions in order — the first 'yes' with a clear steer usually gives you the answer.
- Have you registered for Self Assessment?
No → register by 5 October following the tax year you started. - Do you have a UTR?
No → you'll get one after registration; needed to file. - What's your tax year expected profit?
Below £1,000 → trading allowance may apply. Above → file SA. - Is your total tax bill likely to exceed £1,000?
Yes → HMRC will require payments on account next January. - Do you also have employment income?
Yes → your PAYE tax code should be checked against your total income. - Do you have unusual reliefs (pension, marriage allowance, gift aid)?
Include them on the return — the calculator here doesn't.
Sources & official references
Every rate and threshold in this guide traces back to a published UK official source. All updated for the 2025/26 tax year.
Related on FreelanceToolkit UK
Your numbers
Your estimate
Income tax breakdown
| Band | Rate | Amount in band | Tax |
|---|
National Insurance (Class 4)
| Band | Rate | Amount | NI |
|---|
How this calculator works
Taxable profit = turnover − allowable expenses. Add any PAYE salary to get your total taxable income. The personal allowance is £12,570 in 2025/26, but it's reduced by £1 for every £2 you earn above £100,000 — so it's £0 once you hit £125,140.
Income tax bands (England, Wales & NI, 2025/26)
- Basic rate (20%): £12,571 – £50,270
- Higher rate (40%): £50,271 – £125,140
- Additional rate (45%): over £125,140
Class 4 National Insurance
- 6% on profits between £12,570 and £50,270
- 2% on profits above £50,270
Class 2 NI
No longer compulsory above the Small Profits Threshold — your State Pension entitlement is preserved automatically. You can choose to pay £3.45/week voluntarily if you fall below.
Worked examples
Inputs: turnover £60,000, allowable expenses £8,000. No PAYE, no pension, no student loan.
Result: income tax £8,232, Class 4 NI £2,297, take-home £41,471.
Why: profit £52,000 minus personal allowance £12,570 = £39,430 taxable. £37,700 at 20% basic rate, then £1,730 spills into higher rate at 40%. Class 4 NI is 6% on the full basic-rate band plus 2% on the £1,730 above £50,270.
Inputs: turnover £120,000, expenses £10,000.
Result: income tax £32,432, Class 4 NI £3,457, take-home £74,111.
Why: above £100,000 the personal allowance reduces by £1 for every £2 of extra income. At £110,000 the allowance tapers to £7,570 — so an extra £5,000 of income becomes taxable in the higher-rate band. Effective marginal rate above £100k is 60% (40% income tax plus 20% lost allowance).
Inputs: turnover £20,000, expenses £2,000.
Result: income tax £1,086, Class 4 NI £326, take-home £16,588.
Why: profit £18,000 minus allowance £12,570 = £5,430 taxable at 20%. Class 4 NI is 6% on the £5,430 above the lower profits limit. No higher-rate spillover.
No third-party calculator is "HMRC-approved" — HMRC don't endorse external tools. The figures here use HMRC's published rates and bands for 2025/26 and are cross-checked against worked examples. For your actual return, file through HMRC's Self Assessment portal or paid software.
Yes. The allowance reduces by £1 for every £2 of income above £100,000, hitting £0 at £125,140. The calculator applies this taper automatically and shows the reduced allowance in the breakdown.
Select "Scotland" in the Region dropdown. Scottish income tax has six bands (Starter, Basic, Intermediate, Higher, Advanced, Top) — Class 4 NI is the same UK-wide.
Yes — enter the net amount you paid (e.g. £80 if you wrote a £80 cheque). The calculator grosses it up by 25% to reflect basic-rate relief at source, then extends your basic-rate band by that gross amount. Higher-rate taxpayers get the extra relief through Self Assessment.
Class 2 was a flat £3.45/week and is no longer compulsory above the Small Profits Threshold (£6,725 in 2025/26) — you get the State Pension qualifying year automatically. Class 4 is the profit-based contribution: 6% between £12,570 and £50,270, then 2% above.
Yes — Plans 1, 2, 4 (Scotland), 5, and Postgraduate. Each plan has its own threshold and rate. Repayments are deducted on top of your tax/NI.
Dividends, capital gains, payments on account, marriage allowance transfer, gift aid relief, child benefit charge, IR35 deemed-employment scenarios, and VAT. For limited-company directors, see our limited-company take-home calculator. For VAT-registered freelancers, see the Flat Rate Scheme calculator and the VAT return calculator.
Yes — UK lenders assess sole traders on net profit (SA302), so allowable expenses you've claimed reduce the income figure lenders see. If you're 12+ months from a mortgage application, talk to your accountant about which expenses are optional (e.g. capital-purchase timing). See our freelancer mortgage guide for the full income-assessment picture.
Maybe. Below ~£40k of business profit the saving is marginal; above ~£60k Ltd typically saves £2–5k/year. The breakeven depends on how much you draw vs retain. Use our sole trader vs Ltd calculator to compare your specific numbers, or read the definitive guide.
This calculator is general guidance based on UK rates for the 2025/26 tax year. It is not personal tax advice. For complex situations (CIS, IR35, capital allowances, dividends, second jobs) consult a qualified accountant.