NZ Tax Deadlines and IRD Key Dates 2026-27
Key IRD dates for the 2026-27 tax year (1 April 2026 – 31 March 2027). Income tax, IR3 filing, provisional tax, GST, and terminal tax deadline reference.
Looking specifically for GST due dates?
This calendar lists the one-line GST rule alongside every other IRD date. For your own filing frequency — monthly, two-monthly or six-monthly — with every period end and payment date worked out, use the NZ GST due dates calculator.
IR3 tax return: who must file and when
Most PAYE-only earners never file anything. IRD automatically assesses salary and wages, schedular payments, interest, dividends and taxable Māori authority distributions after the tax year ends, and the result shows up in myIR from late May. You need to file an IR3 individual income tax return if you had more than $200 (before tax) of income IRD hasn't already been told about — typically self-employment or business income, rental income, overseas income, a bright-line property sale, or trust, partnership/look-through-company, or shareholder-employee income.
2025-26 IR3 deadline
7 July 2026 if you file it yourself, or 31 March 2027 if you're a client of a registered tax agent with an extension of time (EOT) — the standard arrangement IRD grants tax agents so they can spread client filing across the year instead of one 7 July peak.
How it feeds into provisional tax
If your IR3 shows residual income tax (RIT) over $5,000, you become a provisional taxpayer the following year, paying in three instalments — for 2026-27 that's 28 August 2026, 15 January 2027, 7 May 2027. See the provisional tax section below for the uplift methods and safe-harbour rule.
Not sure whether you need to file at all? Run the IR3 filing checker (six questions, instant answer), or see the full 2025-26 IR3 filing guide for the document checklist and a step-by-step myIR walkthrough. For the PAYE-vs-IR3 decision logic in more depth, see PAYE vs IR3.
All Key Dates
| Date | Event | Who |
|---|---|---|
| 1 April 2026 | 2026-27 tax year begins | All taxpayers |
| 7 April 2026 | Terminal tax for 2024-25 due (clients of tax agents with extension of time) | Tax agent clients |
| 7 May 2026 | GST return due (period ended 31 March: 2-monthly Feb–Mar and 6-monthly Oct–Mar filers) | GST-registered businesses |
| 7 May 2026 | Provisional tax 3rd instalment for 2025-26 (standard method, March balance date) | Provisional taxpayers |
| 28 June 2026 | GST return due (2-monthly filer: Apr–May period) | GST-registered businesses |
| 7 July 2026 | 2025-26 income tax return (IR3) due (no tax agent or extension of time) | Individual taxpayers |
| 28 August 2026 | Provisional tax 1st instalment for 2026-27 (standard method, March balance date) | Provisional taxpayers |
| 28 August 2026 | GST return due (2-monthly filer: Jun–Jul period) | GST-registered businesses |
| 28 October 2026 | GST return due (2-monthly Aug–Sep and 6-monthly Apr–Sep periods) | GST-registered businesses |
| 15 January 2027 | Provisional tax 2nd instalment for 2026-27 (standard method, March balance date) | Provisional taxpayers |
| 15 January 2027 | GST return due (period ended 30 November — statutory exception) | GST-registered businesses |
| 7 February 2027 | Terminal tax for 2025-26 due (no tax agent) | Individual taxpayers |
| 28 February 2027 | GST return due (2-monthly filer: Dec–Jan period) | GST-registered businesses |
| 31 March 2027 | 2026-27 tax year ends | All taxpayers |
| 31 March 2027 | 2025-26 income tax return (IR3) due (tax agent extension of time) | Tax agent clients |
| 7 April 2027 | Terminal tax for 2025-26 due (clients of tax agents with extension of time) | Tax agent clients |
| 7 May 2027 | Provisional tax 3rd instalment for 2026-27; GST for period ended 31 March 2027 | Provisional taxpayers & GST filers |
Important Notes
- If a due date falls on a weekend or public holiday, the deadline moves to the next working day.
- Provisional tax dates above are for taxpayers with a March balance date using the standard method. AIM and ratio methods have different dates.
- Employers must file employment information within two working days of each payday via ir-File.
- Use a tax agent? You may qualify for extended filing deadlines — check with your agent.
What happens if you miss a deadline
Filing late and paying late are charged separately, and both can apply at once. The figures below follow the Tax Administration Act 1994 and IRD's published use-of-money interest rates — work out your own numbers with the late filing penalty calculator.
Late filing penalty — a flat amount
Under section 139A(3) of the Tax Administration Act 1994, filing an IR3 or IR4 late costs $50 where net income is below $100,000; $250 where net income is $100,000 to $1,000,000 (both inclusive); $500 where net income is above $1,000,000. IRD only charges it on those two return types, and only after giving at least 30 days' notice — file within that window and no penalty applies.
Late payment penalties — 1% then 4%
Section 139B(2)(a) adds 1% of the unpaid tax the day after the due date. If any of it is still owing at the end of the 7th day after that, a further 4% is added — calculated on the tax plus the 1% already charged. The old incremental 1%-per-month penalty no longer applies to income tax or provisional tax for the 2017-18 and later income years.
Use-of-money interest — currently 8.97%
From 16 January 2026, IRD charges 8.97% a year on outstanding tax (including penalties) where the balance is more than $100. Interest is simple and calculated daily — it does not compound — and runs from the day after the due date until you pay. If the overdue period spans a rate change, each stretch is charged at the rate that was in force at the time; see every published UOMI rate.
Worked example: $6,000 paid 48 days late
Say $6,000 of tax was due on 28 August 2026 and wasn't paid until 48 days later, on 15 October 2026 (this example assumes the return itself was filed on time, so no separate filing penalty applies):
- 1% initial late payment penalty: $60.00, added the day after the due date
- 4% further late payment penalty: $242.40, added at day 7 on the tax plus the 1% already charged
- Use-of-money interest: $70.78, at 8.97% a year for 48 days
Total extra cost: $373.18 on top of the $6,000 owed — a bill of $6,373.18 in total, for being seven weeks late.
Provisional tax
Provisional tax applies once your residual income tax (RIT) — tax owed after PAYE, RWT and other withholdings — exceeds $5,000 in a year. It most often catches self-employed people, landlords, and investors, who pay their expected tax in instalments during the year rather than one lump sum after it ends.
Standard uplift method
Each instalment is one-third of your prior year's RIT uplifted by 105% — or 110% of the RIT from two years ago if last year's return wasn't yet filed by the first instalment date. For a March balance date, the three 2026-27 instalments are due 28 August 2026, 15 January 2027, 7 May 2027.
Ratio option
Available if your prior-year RIT was between $5,000 and $150,000, this pays six smaller instalments tied to your GST cycle instead of three larger ones — useful if income is uneven through the year.
Safe harbour — RIT under $60,000
If your RIT is under $60,000 and you paid the standard-uplift instalments in full and on time, IRD does not charge use-of-money interest on the year-end shortfall — it only starts accruing from the terminal tax due date if you're still short then. Miss an instalment or use the estimation method instead, and interest can run from each instalment date.
Terminal tax
Terminal tax is the final square-up for a tax year — the difference between your actual residual income tax and what you already paid through PAYE, withholding and provisional tax instalments. For the 2025-26 year it's due 7 February 2027 if you file yourself, or 7 April 2027 if you're linked to a tax agent who holds an extension of time. If your provisional tax overpaid the year, IRD refunds the difference rather than billing you. Work out your own figure with the terminal tax calculator.
Frequently asked questions
When does the NZ tax year start and end?
The New Zealand tax year runs from 1 April to 31 March. The current tax year is 2026-27 (1 April 2026 – 31 March 2027).
When is my income tax return due?
If you file yourself, your individual income tax return (IR3) is due by 7 July — for the 2025-26 year that means 7 July 2026. If you use a tax agent with an extension of time, you generally have until 31 March of the following year (31 March 2027).
What are provisional tax dates?
For taxpayers with a March balance date using the standard method, the three instalments are due 28 August, 15 January, and 7 May.
When is terminal tax due?
Terminal tax — the end-of-year top-up payment — is due 7 February if you don't have a tax agent, or 7 April if you file through a tax agent with an extension of time.
How often do I need to file GST?
GST filing frequency depends on your turnover: monthly (over $24 million), 2-monthly (most businesses), or 6-monthly (under $500,000). Returns and payments are due on the 28th of the month after the period ends, with two exceptions: a period ending 31 March is due 7 May, and a period ending 30 November is due 15 January.
What is an IR3 tax return?
The IR3 is IRD's individual income tax return, filed by anyone whose income isn't fully covered by an automatic assessment — typically the self-employed, landlords, people with overseas income, or anyone with income not taxed at source. Most PAYE-only employees don't file one at all; IRD assesses them automatically after the tax year ends.
When is my 2026 tax return due?
It depends which year you mean. The return covering the 2025-26 tax year (1 April 2025 – 31 March 2026) was due 7 July 2026 for self-filers, or 31 March 2027 with a tax agent. The return covering the current 2026-27 tax year (1 April 2026 – 31 March 2027) isn't due until 7 July 2027.
What are the IRD due dates for 2026?
For the 2026-27 tax year: provisional tax instalments on 28 August 2026, 15 January 2027, and 7 May 2027; the 2025-26 IR3 return was due 7 July 2026 (self-filers) or is due 31 March 2027 (tax agent clients); and 2025-26 terminal tax is due 7 February 2027, or 7 April 2027 with a tax agent. The full calendar is in the table above.
When are the provisional tax due dates for 2026-27?
For a standard March balance date on the standard uplift method, the three 2026-27 instalments are 28 August 2026, 15 January 2027, and 7 May 2027. Six-monthly GST filers on the standard option pay only two instalments, 28 October 2026 and 7 May 2027. The ratio option uses six two-monthly dates instead.
2025-26 IR3 filing: IR3 2025-26 hub, how to file IR3, common IR3 mistakes, IR3 vs auto-assessment
Related Calculators
Provisional Tax Calculator
Calculate your provisional tax instalments.
GST Calculator
Add or remove 15% GST.
Self-Employment Tax
Income tax, ACC, and provisional tax.
Tax Refund Estimator
Compare PAYE withheld vs actual tax.
Late Filing Penalty Calculator
Missed a date? Penalties and interest on what you owe.
IRD UOMI Interest Rates
Every published use-of-money interest rate and date.
Need the deeper deadline guide?
For late-payment penalties, terminal tax detail, automatic assessment timing, and tax-agent extensions, see IRD Key Dates 2025-26 & 2026-27.
Sources: IRD — Payment dates for provisional tax, IRD — Filing GST, IRD — IR328 tax due date calendar 2026-27 (PDF), IRD — Late filing penalties, IRD — Late payment penalties, IRD — Interest on overpayments and underpayments, IRD — Timelines at the end of the tax year. Last updated August 2026.