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Self-employment income & tax planner

UK sole-trader income estimator — tax year 2026/27 (6 April 2026 to 5 April 2027). Session-only: your financial inputs are not stored or sent.

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Estimates Income Tax, National Insurance (Class 4), student loan and remaining income for a UK sole trader. One shared Personal Allowance is applied to combined employment and trading profit. Turnover is not treated as profit. Rates verified against GOV.UK on 2026-10-01. Not a Self Assessment filing service or advice.
Business figures (annual)
£

Gross takings before expenses — not taxed directly.

£

You enter these — the tool assumes they are allowable.

Trading profit = turnover − expenses. Turnover is never treated as taxable profit.

Employment income (optional)
National Insurance situation

Tick anything that applies. These cases are not supported: National Insurance will be marked as not verified rather than shown as a reliable figure.

Pension contributions

Repayments are based on your total income.

£

e.g. payments on account already made. Not PAYE tax (enter that above).

Previous-year liability (for payments on account)
£

Required to illustrate payments on account. Leave blank to skip.

Enter your annual turnover to see your estimated tax, National Insurance and remaining income.

Assumptions & notes
  • Tax year 2026/27 only (6 April 2026 to 5 April 2027). Rates verified against GOV.UK on 1 October 2026.
  • Trading profit = turnover minus the allowable expenses you enter. Turnover is never treated as taxable profit.
  • One Personal Allowance is applied to your combined income (employment + trading profit) — never two.
  • Adjusted net income deducts grossed-up relief-at-source pension contributions before the Personal Allowance taper is applied.
  • Income Tax is calculated on taxable income using the band widths for your UK region (England, Wales, Northern Ireland share the rest-of-UK bands; Scotland has its own).
  • Class 4 National Insurance is 6% on profits between £12,570 and £50,270 and 2% above £50,270. Class 2 is treated as paid (£0 cost) for 2026/27; voluntary Class 2 is not added.
  • Employment Class 1 NI is estimated from your employment income using annual thresholds (the same verified figures as the take-home estimator). It is collected via PAYE, not Self Assessment.
  • If you also pay Class 1 NI on employment, Class 4 is limited by the annual maximum in regulation 100 (no Class 2 element from 6 April 2024): Steps 1-9 and Cases 1-3 are applied using 6% main, 2% additional and the 8% main primary Class 1 rate. Class 1 at the main rate is estimated from employment income unless you enter your annual earnings subject to main-rate employee NI (above the Primary Threshold, up to the Upper Earnings Limit) — this may require payroll records or a derived calculation and is not usually a single figure on a standard P60.
  • The annual Class 4 maximum is only applied for one employment with standard employee NI. State Pension age, deferment, more than one employment and the reduced-rate election are not supported: NI is then shown as not verified and Class 4 is unadjusted.
  • Student loan repayments are calculated on your TOTAL income (employment + trading profit). Amounts already deducted through PAYE are credited, so they are not counted twice; only the remaining balance is due via Self Assessment.
  • Pension relief at source: 20% basic-rate relief is added to your pot by the provider; higher/additional-rate relief is given through Self Assessment by reducing your tax bill. The annual allowance and tapered annual allowance are not checked.
  • The 'total annual liability' is the tax, Class 4 NI and student loan you owe for the year. The 'amount still payable' subtracts tax already deducted/paid. They are shown separately.
  • The illustrative tax-reserve amount is the total annual liability ÷ 12 — a monthly amount to set aside. The payment-timing view is separate and shows dated cash flows (payments on account and balancing payment).
  • Payments on account toward 2026/27 (the current year) require your previous-year (2025/26) liability and the eligibility rules (£1,000 de-minimis; not more than 80% paid outside Self Assessment). If no previous-year liability is entered, current-year payments on account are not calculated here — this does not mean you have made no payments on account.
  • Payments on account toward 2027/28 (the next year) are illustrated separately, based on this year's (2026/27) liability and the same eligibility rules. They may change once your 2027/28 liability is known.
  • Entered expenses are assumed allowable — this tool does not assess whether a given expense qualifies as a deductible business expense.
Outside this calculator
  • VAT is not calculated. If you are VAT-registered, account for VAT separately.
  • Capital allowances (e.g. annual investment allowance, writing-down allowances) are not calculated; deducting the cost of equipment is outside this tool.
  • Losses (brought forward or made this year) are not carried forward or offset against other income.
  • Combined employment and self-employment NI is calculated only for one employment with standard employee Class 1 NI. More than one employment, deferment, the reduced-rate election and State Pension age are unsupported and are marked as not verified.
  • Property income, dividend income, savings interest and other non-trading income are excluded — this tool covers employment plus self-employment trading profit only.
  • The £1,000 trading allowance is not auto-applied; you enter actual allowable expenses. You cannot claim both.
  • Gift Aid donations, Marriage Allowance, Blind Person's Allowance and other reliefs are not modelled.
  • High Income Child Benefit Charge is not calculated.
  • This tool does not assess whether your expenses are allowable — it assumes the figures you enter are valid deductible business expenses.
  • It is not a Self Assessment filing service, a substitute for professional advice, or a payroll service.
Official sources (tax year 2026/27)