Every rate and threshold on this site is taken from official HMRC and GOV.UK guidance. This page lists the primary sources so you can verify the current position independently. Last reviewed: July 2026.
Updated 2026/27 · SoleTraderTaxCalculator.co.uk · Editorial standards · Methodology
Income tax rates and bands, and the Personal Allowance and its taper above £100,000, are taken from GOV.UK: gov.uk/income-tax-rates and gov.uk/income-tax-rates/income-over-100000.
For 2026/27 we apply a Personal Allowance of £12,570, basic rate 20% to £50,270, higher rate 40% to £125,140, and additional rate 45% above £125,140.
Scottish income tax bands, set by the Scottish Government, are taken from GOV.UK: gov.uk/scottish-income-tax. These apply to non-savings, non-dividend income for Scottish taxpayers, while the Personal Allowance remains UK-wide.
Class 2 and Class 4 National Insurance rates and thresholds are taken from GOV.UK: gov.uk/self-employed-national-insurance-rates. For 2026/27 we apply Class 4 at 6% between £12,570 and £50,270 and 2% above £50,270, with Class 2 relevant for those below the small-profits threshold or paying voluntarily to protect their contribution record.
Self Assessment deadlines, penalties and the payments-on-account system are taken from GOV.UK: gov.uk/self-assessment-tax-returns, gov.uk/pay-self-assessment-tax-bill and gov.uk/understand-self-assessment-bill/payments-on-account.
Allowable expenses and the £1,000 trading allowance are taken from GOV.UK: gov.uk/expenses-if-youre-self-employed and gov.uk/tax-free-allowances-on-property-and-trading-income. Making Tax Digital for Income Tax guidance is taken from gov.uk/guidance/using-making-tax-digital-for-income-tax.
Student and postgraduate loan repayment thresholds and rates are taken from GOV.UK: gov.uk/repaying-your-student-loan. These are applied through Self Assessment for self-employed borrowers.
We review these sources at each UK Budget and at the start of each tax year, and update affected pages when official guidance changes. If you believe a figure is out of date, please contact us with a link to the relevant GOV.UK page so we can verify and correct it.
The sole trader tax calculator turns this guidance into a concrete monthly take-home and tax reserve estimate, based on 2026/27 HMRC rates. Enter taxable profit — not turnover.
Self Assessment checklist, expense tracker and payments on account calendar — all in one practical PDF. Updated for 2026/27.
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