NZ provisional tax calculator 2026-27
Work out your New Zealand provisional tax instalments for the year ending 31 March 2027 (or 2028). Use the standard option (last year's residual income tax plus 5%, or 2 years ago plus 10% if you have an extension of time) or the estimation option. You get the amount and due date of each instalment. There's also a residual income tax (RIT) calculator for sole traders and anyone with income that isn't taxed at source. Every rule follows the IRD's provisional tax guide (IR289), and the calculator matches all of its worked examples.
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Provisional taxRIT calculatorWorked examplesDue datesFAQ
Residual income tax (RIT) calculator
RIT is your income tax for the year minus PAYE and other tax credits (such as RWT on interest). Provisional tax applies when it's over $5,000. ACC levies for the self-employed are invoiced separately by ACC, so they aren't part of RIT.
Worked examples (IRD IR289)
Standard option: RIT of $10,130 last year. Provisional tax = $10,130 + 5% = $10,636, paid as 3 instalments: $3,545, $3,545 and $3,546.
Working out RIT (Matt, 2025 year): salary $14,800 + self-employed net profit $47,600 = taxable income $62,400. Tax on $62,400 (2025 composite rates) = $11,205.32. Less PAYE $1,610 = RIT $9,595.32. That's over $5,000, so Matt pays provisional tax the next year.
Estimation option (Hiwi, 2026 year): net profit $170,600 + salary $78,000 = $248,600. Tax = $76,031.50, less PAYE $16,660 = estimated RIT $59,371.50. Three instalments of $19,790.50. In February Hiwi re-estimates to $65,000. He's paid $39,581, so his final instalment on 7 May is $25,419.
Extension of time (Ned's company): 2021 RIT $24,000 + 10% = $26,400, so instalments of $8,800 on 28 August and 15 January. The 2023 return, filed on 23 January, shows RIT of $23,740. The final instalment is $23,740 + 5% ($1,187) − $17,600 = $7,327.
Due dates (31 March balance date)
| Year ending | 3 instalments | 2 instalments (6-monthly GST) |
|---|---|---|
| 31 March 2027 | 28 Aug 2026, 15 Jan 2027, 7 May 2027 | 28 Oct 2026, 7 May 2027 |
| 31 March 2028 | 28 Aug 2027 (pay by Mon 30 Aug), 15 Jan 2028 (pay by Mon 17 Jan), 7 May 2028 (pay by Mon 8 May) | 28 Oct 2027, 7 May 2028 (pay by Mon 8 May) |
When a due date falls on a weekend or public holiday, a payment on the next working day counts as on time. The calculator moves weekend dates for you. Check public holidays yourself.
Rates used for RIT
Years ending 31 March 2026 onwards: 10.5% to $15,600, 17.5% to $53,500, 30% to $78,100, 33% to $180,000, 39% above. The year ending 31 March 2025 uses the IRD's composite rates: 10.5% to $14,000, 12.82% to $15,600, 17.5% to $48,000, 21.64% to $53,500, 30% to $70,000, 30.99% to $78,100, 33% to $180,000 and 39% above. Tax credits such as the independent earner tax credit aren't included.
FAQ
Who has to pay provisional tax in NZ?
You pay provisional tax if your residual income tax (the tax left to pay after PAYE and other credits) was more than $5,000 last year. It’s common for sole traders, landlords and anyone with income that isn’t taxed at source.
How is provisional tax calculated with the standard option?
Your previous year’s residual income tax plus 5%. If you have an extension of time and haven’t filed last year’s return in time, early instalments use your RIT from 2 years ago plus 10%, and a catch-up comes at the last instalment.
When are provisional tax payments due?
For a 31 March balance date: 28 August, 15 January and 7 May. If you’re registered for GST and file 6-monthly, you pay 2 instalments on 28 October and 7 May.
Do I pay interest on provisional tax?
With the standard option, if your residual income tax is under $60,000 and you pay each instalment in full and on time, no use-of-money interest is charged before your final tax due date. Other options and late payments can attract interest and penalties.
Should I use the standard or estimation option?
The standard option is simple and protected by the safe harbour. If your income is dropping, the estimation option lets you pay based on a fair and reasonable estimate, but interest can apply if it turns out too low.
What is residual income tax (RIT)?
It’s your income tax for the year minus PAYE deducted and other tax credits, such as resident withholding tax on interest. Working for Families tax credits aren’t deducted.
Sources (checked 17 Oct 2026): IRD Provisional tax guide (IR289); IRD Standard option; IRD Tax rates for individuals.
General information, not tax advice. Check your instalments in myIR or with a tax agent. The ratio option and AIM aren't covered here.