Provisional Tax Due Date Calculator NZ 2026/27
This calculator works out exactly when your New Zealand provisional tax is due, so you are never caught off guard by an Inland Revenue payment date. Provisional tax is paid in instalments through the year rather than as one lump sum at year end, and the dates those instalments fall on depend on two things: your income tax balance date, which is 31 March for most individuals, sole traders and small companies, and how often you file GST, since two-monthly and monthly GST filers pay three instalments while six-monthly filers pay only two. Select your balance date, your GST filing basis, and whether you use a registered tax agent, and the calculator shows your instalment dates for the year plus your terminal tax date, the final wash-up between what you actually owe and what you have already paid. If you have a non-standard balance date, the calculator applies Inland Revenue's general day-count rule, the 28th of the 5th, 9th and 13th month after the start of your income year, with the same December and April exceptions that apply to the standard 31 March cycle, so you get a genuinely useful estimate rather than just the one case everyone else covers. It updates instantly as you change any setting, with no need to press a button. Use it to put dates in your calendar, to plan cash flow ahead of each instalment, or to check a date an accountant or software package has given you. Always treat the results as a planning guide and confirm your exact dates in myIR, particularly if your balance date is not 31 March.
Non-standard balance dates: calculated using Inland Revenue's general rule, the 28th day of the 5th, 9th and 13th month after the start of the income year, with the same two exceptions (a due date of 28 December moves to 15 January; a due date of 28 April moves to 7 May). Terminal tax without a tax agent is shown as 7 months and 7 days after the equivalent standard pattern; with a tax agent it follows the same pattern as the 31 March case. Inland Revenue can set individual non-standard schedules through myIR, so confirm your exact dates there.
Provisional tax threshold: required when residual income tax (RIT) for the prior year exceeds $5,000.
Weekend/public holiday rule: if a due date falls on a weekend or public holiday, payment on the next working day is treated as on time. This calculator shows the nominal date and does not shift for weekends or holidays in a specific year.
Last verified: 1 July 2026, against current Inland Revenue guidance.
Source data: Inland Revenue (payment dates for provisional tax) and the standard option guidance.
| Instalment | Due date | Status |
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Terminal tax due date
These dates match Inland Revenue's published schedule for a standard 31 March balance date.
How provisional tax due dates are set
Provisional tax due dates are set by Inland Revenue based on two things: your income tax balance date and how often you file GST. Most New Zealand individuals, sole traders and small companies use the standard 31 March balance date, and if they file GST two-monthly or monthly, or are not GST-registered at all, they pay provisional tax in three equal instalments: 28 August, 15 January and 7 May. Six-monthly GST filers pay in only two instalments instead, timed to line up with their GST return dates: 28 October and 7 May. Businesses using the GST ratio method can pay in up to six instalments aligned with each two-monthly GST period, and the AIM method pays alongside GST returns based on actual accounting income rather than fixed instalment dates.
If your balance date is not 31 March, Inland Revenue applies a general rule rather than a completely separate table: instalments are generally due on the 28th day of the 5th, 9th and 13th month after the start of your income year, with the same two calendar exceptions that apply to the standard cycle. A due date that would land on 28 December instead falls on 15 January, to keep it clear of the Christmas and New Year shutdown, and a due date that would land on 28 April instead falls on 7 May, to align with terminal tax timing. This calculator applies that same rule to whichever balance date you select, so you get a genuine estimate rather than being told to look it up elsewhere.
Worked examples
Example 1, standard balance date: Aroha runs a small graphic design business as a sole trader with the standard 31 March balance date. She files GST two-monthly and does not use a tax agent. For the 2026/27 tax year, ending 31 March 2027, her three provisional tax instalments are due 28 August 2026, 15 January 2027 and 7 May 2027. Once the year closes, her terminal tax, the final settling-up between what she actually owes and what she has already paid in instalments, is due 7 February 2028.
Example 2, six-monthly GST with a tax agent: Tane runs a landscaping business, also with a 31 March balance date, but keeps his GST filing simple by using the six-monthly option, and works with a registered tax agent to file his return. Because he files six-monthly he pays only two provisional tax instalments instead of three: 28 October 2026 and 7 May 2027. Because his tax agent has an extension of time arrangement in place, his terminal tax is due 7 April 2028 rather than 7 February 2028.
Example 3, non-standard balance date: Coastal Builders Ltd runs its accounts to a 30 June balance date rather than the standard 31 March. For its year ending 30 June 2027, filing GST two-monthly, the general rule gives three instalments of 28 November 2026, 28 March 2027 and 28 July 2027, being the 5th, 9th and 13th month after the income year began on 1 July 2026. Its terminal tax, without a tax agent, falls due 7 May 2028. Coastal Builders still checks these dates against its myIR account, since Inland Revenue can set individual arrangements for non-standard balance dates.
Terminal tax and the effect of a tax agent
Terminal tax is different from a provisional tax instalment. It is the final wash-up once your actual income tax liability for the year is known: if your instalments added up to less than you owed, the shortfall is due as terminal tax, and if they added up to more, you receive a refund. For a standard 31 March balance date, terminal tax is due 7 February the following year if you file your own return, or 7 April if you are linked to a registered tax agent with an extension of time arrangement, which effectively gives you two extra months. A tax agent does not move your provisional tax instalment dates during the year, only the terminal tax date at the end of it. For a full breakdown of how the wash-up itself is calculated, see the Terminal Tax Calculator.
Who needs to pay provisional tax
You only need to pay provisional tax if your residual income tax, your total tax bill after PAYE and other credits, was more than $5,000 in the prior year. This typically applies to self-employed people, contractors, landlords and anyone with investment income that is not taxed at source. If your residual income tax was $5,000 or less, you are in the safe harbour and can simply pay your full tax bill as terminal tax once the year ends, without instalments along the way.
What this calculator assumes
- The standard or estimation method is used, not the GST ratio method (up to 6 instalments) or AIM (payments aligned with actual accounting income, not fixed dates).
- Two-monthly and monthly GST filers, and taxpayers not registered for GST, follow the standard 3-instalment pattern.
- Six-monthly GST filers follow the 2-instalment pattern, confirmed against Inland Revenue for a 31 March balance date and calculated using the same general rule for other balance dates.
- Non-standard balance date instalment dates are calculated using Inland Revenue's published general rule (5th, 9th and 13th month after the start of the income year, with the December and April exceptions).
- Dates shown are nominal and are not shifted for weekends or public holidays in a specific year; if a date falls on a non-working day, payment on the next working day is treated as on time.
- Non-standard balance date schedules, especially terminal tax with a tax agent, can be set individually by Inland Revenue, so confirm your exact dates in myIR.
Who this calculator is for
This calculator is for anyone who pays New Zealand provisional tax and wants their instalment and terminal tax dates in one place: self-employed people and contractors, small business owners, landlords with rental income, and the accountants and bookkeepers who manage due dates on their behalf. It is equally useful whether you have the standard 31 March balance date or a different one, since the underlying rule Inland Revenue uses is general rather than specific to March balance dates alone.
Related calculators
- Provisional Tax Calculator: work out your actual instalment amounts under the standard uplift, estimation and AIM methods, not just the dates.
- Terminal Tax Calculator: the wash-up between your total tax liability and the provisional tax you have already paid.
- GST Due Dates 2026/27: the complete GST return and payment deadline schedule by filing frequency.
- GST Filing Frequency Chooser: work out whether monthly, two-monthly or six-monthly GST filing suits you.
- Use-of-Money Interest Calculator: the cost of paying provisional tax late or underpaying an instalment.
- Provisional Tax Explained Guide: background on this topic.
- End of Financial Year Checklist - New Zealand: background on this topic.
Official NZ sources
This calculator is built from primary New Zealand sources. Always confirm current figures against the official source for your situation:
- Inland Revenue (IRD): payment dates for provisional tax
- Inland Revenue (IRD): working out provisional tax using the standard option
- Inland Revenue (IRD): provisional tax overview