Self-employed tax calculator
Sole traders pay income tax and Class 4 National Insurance on their profits through Self Assessment. Estimate your bill and how much to put aside each month.
Tax on self-employed profits
| Profit | Income tax | Class 4 NI | After tax | Set aside |
|---|---|---|---|---|
| £20,000 | £1,486 | £446 | £18,068 | 9.7% |
| £30,000 | £3,486 | £1,046 | £25,468 | 15.1% |
| £40,000 | £5,486 | £1,646 | £32,868 | 17.8% |
| £50,000 | £7,486 | £2,246 | £40,268 | 19.5% |
| £75,000 | £17,432 | £2,757 | £54,811 | 26.9% |
| £100,000 | £27,432 | £3,257 | £69,311 | 30.7% |
Self-employed people pay less National Insurance than employees on the same income: Class 4 is 6% between £12,570 and £50,270 against 8% for employees, and there is no employer contribution.
Deadlines
- 31 January 2028: online return and balancing payment for 2026/27, plus the first payment on account for 2027/28.
- 31 July: second payment on account.
- Payments on account are each half of the previous year's bill and apply if your bill is over £1,000 and less than 80% was taxed at source.
Making Tax Digital
From April 2026 sole traders and landlords with qualifying income over £50,000 must keep digital records and send quarterly updates to HMRC; the threshold falls to £30,000 in April 2027 and £20,000 in April 2028.
FAQ
What can I deduct as expenses?
Costs incurred wholly and exclusively for the business: stock, travel (not commuting), equipment, phone and internet use for work, accountancy fees and a share of home running costs. You can use the £1,000 trading allowance instead if your expenses are small.
Do I pay tax on my first £12,570?
No, the Personal Allowance applies to profits in the same way as to salary, and Class 4 starts at £12,570.