Self-Employed Tax Calculator
Estimate your Self Assessment bill as a sole trader or freelancer, and how much to put aside each month so January is not a shock.
Your business
Use whichever is higher. Allowable expenses include materials, travel, phone, insurance and accountancy fees.
Payments on account: because your bill is over £1,000, HMRC will usually ask you to pay half of next year’s bill in advance, by 31 January and 31 July, on top of this bill.
2026/27 rates for the self-employed
| Profit | Income Tax | Class 4 NI |
|---|---|---|
| Up to £12,570 | 0% | 0% |
| £12,571 to £50,270 | 20% | 6% |
| £50,271 to £125,140 | 40% | 2% |
| Over £125,140 | 45% | 2% |
Worked example: £35,000 profit
Income Tax is 20% of (£35,000 − £12,570) = £4,486. Class 4 NI is 6% of the same £22,430 = £1,345.80. Your total bill is £5,831.80, so you keep £29,168.20, and should put aside about £486 a month.
Payments on account
If your bill is more than £1,000, HMRC usually asks you to pay towards next year’s bill in two instalments of 50%, on 31 January and 31 July. In your first year this can mean paying 150% of a year’s bill in one January, so plan ahead.
Also employed? Check your job’s pay with the take-home pay calculator.
Estimate for guidance. It does not include capital allowances, losses, Gift Aid or pension contributions. Check your figures with HMRC or an accountant.
Sources
Figures are checked against these official sources. Last reviewed 7 November 2026.
Common questions
How much tax do I pay when self-employed?
You pay Income Tax on your profit above the £12,570 personal allowance (20% up to £50,270, 40% above), plus Class 4 National Insurance at 6% on profits between £12,570 and £50,270 and 2% above that.
Do I still pay Class 2 National Insurance?
No. Since April 2024 Class 2 has not been compulsory. If your profits are above the small profits threshold (£7,105 in 2026/27) you get National Insurance credits automatically. Below that, you can choose to pay voluntary Class 2 at £3.65 a week to protect your State Pension.
What is the £1,000 trading allowance?
If your business income is small, you can deduct a flat £1,000 instead of your actual expenses. If your turnover is under £1,000 you do not need to tell HMRC at all. Use actual expenses if they are higher.
When do I pay my Self Assessment bill?
The deadline for online returns and payment is 31 January after the tax year ends. For 2026/27 that is 31 January 2028. If your bill is over £1,000 you will usually also make payments on account in January and July.
How much should I save for tax?
A simple rule is to put aside 25 to 30% of your profit if you are a basic-rate taxpayer. This calculator shows the exact monthly figure for your profit.