UK Self Assessment Tax & Take-Home Pay Calculator
Estimate sole trader Income Tax, Class 4 National Insurance, Student Loan repayments, and Payments on Account in seconds.
Annual Income & Expenses (2026/27)
Include £1,000 Trading Allowance if your actual expenses are lower.
HMRC Self Assessment Estimate
2026/27 Tax & Take-Home Summary
Includes 50% first Payment on Account (£4,410.90) toward 2027/28, plus a second £4,410.90 due by 31 July.
2026/27 UK Self Assessment Tax & National Insurance Guide
Sole traders, freelancers, landlords, and CIS subcontractors in England, Wales, and Northern Ireland pay Income Tax and Class 4 National Insurance on net taxable profits above the £12,570 Personal Allowance. For 2026/27, mandatory Class 2 National Insurance has been abolished for self-employed individuals with profits above £6,725 (while preserving State Pension entitlement automatically), leaving Class 4 NI at 6% on profits between £12,570 and £50,270 and 2% above £50,270.
Frequently Asked Questions
How is UK Self Assessment tax calculated for sole traders in 2026/27?
HMRC calculates Self Assessment tax on your net taxable profit (gross self-employed turnover minus allowable business expenses). Profits above the £12,570 Personal Allowance are taxed at 20% (Basic Rate up to £50,270), 40% (Higher Rate up to £125,140), and 45% (Additional Rate above £125,140), plus Class 4 National Insurance at 6% and 2%.
When do HMRC Payments on Account apply?
If your Self Assessment tax and Class 4 NI bill exceeds £1,000, HMRC collects two advance instalments toward the next tax year—each equal to 50% of your current bill—due on 31 January and 31 July.