Free New Zealand calculator · 2026/27

Sole Trader Tax Calculator NZ: Income Tax, ACC & Provisional Tax

Estimate what to set aside from your self-employed profit for income tax, ACC levies and student loan, and see whether provisional tax applies this year. KiwiSaver is shown separately because it is savings, not tax.

Rules and rates checked against official sources on 2 November 2026 · NZD · Estimates only

How is sole trader tax calculated in NZ?

A sole trader pays income tax on net profit (business income minus deductible expenses) at the individual rates: 10.5% to $15,600, 17.5% to $53,500, 30% to $78,100, 33% to $180,000 and 39% above. ACC levies are invoiced separately by ACC. Student loan repayments are 12% of income over $24,128.

You pay provisional tax in the current year if last year’s residual income tax (RIT) — tax on your return after PAYE and other credits — was more than $5,000. Under the standard option it is last year’s RIT plus 5%, usually in three instalments. KiwiSaver is voluntary savings, not tax.

Your details

Your business

Business income for the year (NZ$, excl. GST)Sales or fees before expenses. Leave GST out if you are GST-registered.

Deductible business expenses (NZ$)Costs of earning the income, such as materials, vehicle, phone and depreciation.

Other income and tax already paid

Salary or wages from a job (NZ$, optional)Gross pay from employment, if you also have a job.

Income tax already deducted (NZ$, optional)PAYE income tax on that job (not ACC), plus any schedular withholding tax or RWT credited to you.

Provisional tax and ACC

Last year’s residual income tax (NZ$)From your last IR3 assessment in myIR. Enter 0 if this is your first year.

Provisional tax instalments

ACC work levy + Working Safer levy ($ per $100)2026/27 averages are $0.69 work levy + $0.08 Working Safer. Your classification unit rate is on your ACC invoice.

I work in the business more than 30 hours a week on average (ACC minimum of $50,501 can apply)

I have a student loan

Student loan already deducted from wages (NZ$)

KiwiSaver (savings — kept separate from tax)

Voluntary KiwiSaver you plan to pay this year (NZ$)Self-employed members choose how much to contribute.

I am 16–64 and eligible for the government contribution

Your estimate

Tax, ACC and student loan to set aside from your profit—

Net profit—

Income tax on business profit—

Residual income tax (RIT) this year—

ACC levies (invoiced by ACC)—

Student loan to pay—

Provisional tax instalments (standard option)—

Terminal tax after provisional tax—

KiwiSaver (separate from tax)—

Enter your details to calculate.

How the numbers work

Net profit = business income − deductible expenses.
Income tax is worked out on your total taxable income (profit + any wages). The “tax on business profit” figure is the extra tax your profit adds on top of your wages.
Residual income tax = income tax − tax already deducted (PAYE, withholding tax, RWT). This is what drives provisional tax.
Provisional tax this year uses last year’s RIT, not this year’s estimate. If last year’s RIT was over $5,000: (last year’s RIT × 1.05) ÷ 3.
Terminal tax = this year’s RIT − provisional tax paid. A negative figure is a refund.
ACC: earners’ levy of 1.75% on liable earnings up to $156,641, plus the work and Working Safer levies for your industry. Full-timers earning under $50,501 are levied on $50,501.

2026/27 provisional tax dates (31 March balance date)

Instalment	3 instalments	2 instalments (6-monthly GST)
First	28 August 2026	28 October 2026
Second	15 January 2027	—
Final	7 May 2027	7 May 2027

Terminal tax for the 2026/27 year is due on 7 February 2028, or 7 April 2028 if you have a tax agent with an extension of time. Dates move to the next working day if they fall on a weekend or public holiday. IRD also offers the estimation, ratio and AIM options; this calculator models the standard option only.

Worked example: a $90,000 profit

Hemi is a self-employed electrician. His business brings in $120,000 (excl. GST) with $30,000 of expenses, so his net profit is $90,000. He has no other income.

Income tax: $1,638 + $6,632.50 + $7,380 + $3,927 = $19,577.50.
ACC: earners’ levy $1,575.00 (1.75%) + work and Working Safer levies at $0.77 per $100 = $693.00 → $2,268.00.
Set aside: $21,845.50, about 24.3% of profit.
Last year’s RIT was $15,000, so provisional tax this year is $15,750, paid as $5,250 × 3.
Terminal tax: $19,577.50 − $15,750 = $3,827.50, due 7 February 2028.

If Hemi’s RIT last year had been $4,000, he would not have to pay provisional tax this year. He would pay the full $19,577.50 as terminal tax, and because it is over $5,000 he would become a provisional taxpayer for 2027/28.

Limits of this estimate

It does not decide which expenses are deductible, and it does not handle losses, depreciation recovery, home-office apportionment or ring-fenced rental losses.
It ignores tax credits such as the independent earner tax credit, donations credits and Working for Families.
ACC invoices are based on the earnings in your tax return and may arrive the following year. Work levy rates vary by classification unit.
Use-of-money interest, the estimation, ratio and AIM options, and the 2-years-ago + 10% rule (used when last year’s return is filed late) are not modelled.
Student loan interim payments apply if your end-of-year repayment obligation was more than $1,000; they are not split out here.

Official sources

Checked 2 November 2026:

Frequently asked questions

How much tax should a sole trader put aside in NZ?

Work out income tax on your net profit at the individual rates, then add ACC levies and any student loan repayment. On a $90,000 profit with average ACC levies that is about $21,846, or roughly 24% of profit.

When do I have to pay provisional tax?

When your residual income tax for the previous year was more than $5,000. RIT is the tax on your return after PAYE, withholding tax and other credits.

How is provisional tax worked out under the standard option?

Take last year’s residual income tax and add 5%, then split it into three instalments (or two if you file GST six-monthly). This year’s actual tax is squared up later as terminal tax.

Is ACC included in provisional tax?

No. ACC levies for self-employed people are invoiced by ACC, separately from income tax and provisional tax.

Is KiwiSaver compulsory for self-employed people?

No. Self-employed KiwiSaver members choose how much to contribute. Contributing at least $1,042.86 between 1 July and 30 June can earn the maximum government contribution of $260.72, if you are eligible and your income is $180,000 or less.

Do I include GST in my business income?

No, if you are GST-registered. Income tax is calculated on GST-exclusive income and expenses.