This page shows income tax, Class 2 NI, Class 4 NI and a quarterly set-aside estimate using current 2025/26 assumptions.
Updated for 2025/26 · Reviewed by James Whitfield · Methodology and assumptions
| Annual profit | £18,000.00 |
| Personal allowance | £12,570.00 |
| Taxable income | £5,430.00 |
| Income tax — Basic rate (20%) | £1,086.00 |
| Income tax — Higher rate (40%) | £0.00 |
| Income tax — Additional rate (45%) | £0.00 |
| Class 2 NI | £179.40 |
| Class 4 NI — £12,570 to £50,270 (6%) | £325.80 |
| Class 4 NI — Above £50,270 (2%) | £0.00 |
| Total deductions | £1,591.20 |
| Net income | £16,408.80 |
Monthly net income
£1,367.40
Weekly net income
£315.55
Effective deduction rate
8.8%
Set aside £795.60 per quarter. Payment dates are typically 31 January and 31 July.
For £18,000 profit, the estimate combines income tax by band, Class 2 NI (where applicable) and Class 4 NI, then shows total deductions and net income.
Self-employed NI includes Class 2 (flat annual amount above the threshold) and Class 4 (6% then 2% by profits band). This page shows both parts separately.
A planning estimate is £795.60 per quarter for payments on account, with due dates typically 31 January and 31 July.
Get a PDF of this self-employed calculation with tax, NI and quarterly set-aside values.
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