UK sole traders pay Income Tax and Class 4 National Insurance on their profits through Self Assessment. For 2026/27 the personal allowance stays at £12,570, the basic rate runs to £50,270, and Class 4 NI is 6% between those two figures and 2% above. The thresholds are frozen, so rising income pulls more of it into the higher bands.
Two things catch new freelancers out: payments on account, which can mean paying one and a half years' tax in your first January, and forgetting that a salary from a job uses up your allowance first. The calculators below handle both.
1. Work out your tax and NI
Income Tax and Class 4 NI on your profit for 2026/27, with any salary included, plus your payments on account.
2. Set your day rate
Contracting in the UK is often priced by the day. Convert between day, hourly and annual figures, and check the rate covers your costs.
- Day Rate Calculator: Day Rate to Hourly and AnnualConvert a contractor day rate to an hourly rate and annual income, or work back from an hourly rate or annual target to a day rate.
- Freelance Hourly Rate CalculatorWork out an hourly rate that actually covers your income goal, expenses, and self-employment tax, not just a guess.
3. Invoice correctly
Add or remove VAT if you're registered, set clear payment terms, and work out interest on late invoices.
- VAT and Sales Tax CalculatorAdd tax to a net price, or take it out of a price that already includes it. Works with any currency and any rate.
- Invoice Due Date Calculator (Net 30, Net 60)Find the exact due date for Net 7, Net 30, Net 60, EOM and 2/10 Net 30 payment terms, with the weekday and any early-payment discount.
- Late Payment Interest CalculatorWork out the interest owed on an overdue invoice from the amount, an annual interest rate and the number of days it is late.
Questions people ask
When is the 2026/27 Self Assessment deadline?
The online return and any balance due for 2026/27 are due by 31 January 2028. Payments on account for the following year are due on 31 January and 31 July.
Do I still pay Class 2 National Insurance?
No. Class 2 is no longer charged. If your profits are low, you can pay voluntary Class 2 to protect your State Pension record.
Does this work for Scotland?
The National Insurance figures do, but Scotland sets its own Income Tax bands and rates, so the Income Tax estimate won't match for Scottish taxpayers.