Snag listHome › Self-employed tax › Tax estimate
Tax estimate
Estimate your 2026–27 Income Tax and National Insurance.
Enter your self-employed profit to estimate Income Tax and Class 4 National Insurance for 2026–27, and how much to put aside each month. It runs on this device.
Rules last checked against the official pages on 9 October 2026.
Tax estimate
Estimate Income Tax and Class 4 National Insurance
Turnover means your income before expenses. Profit means your income after allowable business expenses: enter your profit. The estimate assumes this profit is your only income (no salary, pension, savings, dividends or rental income). It doesn't include student loan repayments, pension contributions, Gift Aid or other reliefs, or voluntary Class 2 National Insurance.
Keep your records for the tax year. Sole trader records (Excel, £12 once) adds up income, expenses and mileage by quarter and gives a year-end profit for your return. It suits sole traders under the Making Tax Digital threshold; above it, a spreadsheet needs bridging software to send updates to HMRC.