NZ Sole Trader / Contractor Tax & Provisional Tax Calculator
Calculate NZ sole trader income tax, ACC CoverPlus levies, 3-instalment provisional tax obligations, and recommended Hnry-style invoice set-aside percentages.
Calculate NZ sole trader income tax, ACC CoverPlus levies, 3-instalment provisional tax obligations, and recommended Hnry-style invoice set-aside percentages.
Calculate NZ sole trader income tax, ACC CoverPlus levies, 3-instalment provisional tax obligations, and recommended Hnry-style invoice set-aside percentages. Calculate exact, penny-accurate projections compliant with 2026 Inland Revenue (IRD) • ACC • Reserve Bank of New Zealand (RBNZ) standards using Calconova's deterministic IEEE-754 (Decimal.js) calculation engine with instant breakdowns.
Inland Revenue & ACC sole trader statutory parameters
Home office, motor vehicle, software, phone & professional fees
Used for standard uplift method (105% of prior year RIT).
Transferring 21.3% of every invoice into a dedicated tax buffer account guarantees full coverage for Inland Revenue income tax, ACC CoverPlus, and student loan without year-end cash crunch.
Net\ Profit = Gross\ Revenue - Claimable\ Expenses \\
Income\ Tax = \sum (Band_i \times Rate_i) \\
ACC_{CoverPlus} = Profit \times Rate_{CU} + \min(Profit, \$142,283) \times 1.60\% \\
Provisional\ Tax = \begin{cases} Prior\ RIT \times 105\%, & \text{if } RIT > \$5,000 \\ 0, & \text{otherwise} \end{cases} \\
Instalment = \frac{Provisional\ Tax}{3} \quad (\text{28 Aug, 15 Jan, 7 May})Sole traders pay personal income tax on net business profit plus ACC CoverPlus levies (work levy based on industry risk plus 1.60% Earner's levy). If Residual Income Tax exceeds $5,000, IRD mandates Provisional Tax (standard uplift: 105% of previous year's tax) paid in three instalments on 28 August, 15 January, and 7 May.
All calculations, amortizations, and scenario projections displayed on this page are strictly for informational and educational purposes. Nothing herein constitutes investment, financial, tax, or legal advice. Actual Reserve Bank of New Zealand (RBNZ) interest rates, IRD PAYE brackets, ACC Earner's Levy, KiwiSaver regulations, and lender criteria may vary. Calconova explicitly disclaims all liability for any decisions taken based upon these calculations. Consult a qualified financial advisor, CPA, or official Inland Revenue documentation prior to executing financial commitments.
Provisional tax is paying income tax in instalments throughout the tax year rather than a lump sum. You must pay provisional tax if your Residual Income Tax (RIT) from your last tax return was more than $5,000.
For the standard 31 March tax balance date, the three instalment due dates are: 1st instalment on 28 August, 2nd instalment on 15 January, and 3rd instalment on 7 May.
Automated services like Hnry calculate the exact percentage of every invoice (usually 25% to 35%) to set aside automatically for income tax, ACC levies, and student loan, eliminating end-of-year tax shock.
Standard CoverPlus calculates injury compensation based on your previous year's audited taxable income. CoverPlus Extra allows self-employed individuals to negotiate a guaranteed pre-agreed weekly payout regardless of recent income.
Add 15% GST or extract embedded GST using New Zealand's official 3/23 statutory fraction with instant penny precision and multi-item quote builder.
Calculate IRD Schedule 4 Withholding Tax (WT code) deductions on contractor invoices, GST components, net payouts, and end-of-year tax reconciliation.
Calculate your exact New Zealand net take-home pay under Inland Revenue (IRD) 2025/2026 tax brackets, ACC Earner's Levy (1.60%), KiwiSaver, IETC credit, and Student Loan deductions.