IRD Key Dates 2026: NZ Tax Deadlines, Returns Due 7 July

Missing an IRD deadline in New Zealand can mean late filing penalties, use-of-money interest, or both. The 2025-26 tax year runs from 1 April 2025 to 31 March 2026, but many associated obligations fall after that date — sometimes well into 2027. This article sets out every key date you need to track, from provisional tax instalments during the year to terminal tax and the final return deadline.

The NZ Tax Year at a Glance

The New Zealand income tax year is not the calendar year. It runs 1 April to 31 March. For 2025-26 that means:

• Start: 1 April 2025
• End: 31 March 2026
• Returns due: July 2026 (standard) or later with a tax agent

This offset matters because payments and returns relating to the 2025-26 year can extend deep into calendar year 2026 and early 2027.

Individual Tax Returns (IR3)

Who needs to file an IR3?

Not every individual needs to file an IR3 return. You are generally required to file if you:

• Are self-employed or receive schedular payments
• Have rental income
• Earned income not taxed at source (interest, dividends over the withholding threshold)
• Have overseas income
• Were in business as a partner or shareholder earning salary, wages, or director’s fees
• Have a student loan and earned income from multiple sources

Most employees with only PAYE income will have their tax automatically calculated by IRD through the end-of-year process (the automatic assessment), and many will not need to file anything.

IR3 due dates for 2025-26

If you are unsure whether you need to file, log in to myIR and check whether IRD has issued an automatic assessment for your account. If an assessment has been issued and you agree with it, you can simply accept it. If it is wrong — for example because it does not include rental income — you should file an IR3 to correct the position.

Automatic Assessments

From April 2019, IRD has automatically assessed most wage and salary earners at the end of each tax year. For 2025-26, automatic assessments for the year ended 31 March 2026 are typically issued from May 2026 onward. You have until 7 July 2026 to dispute an automatic assessment if you believe it is incorrect.

Provisional Tax

Provisional tax applies to people whose residual income tax (RIT) — the income tax remaining after PAYE and other withholdings — exceeds $5,000. This most commonly affects self-employed people, landlords, and investors.

Standard Instalment Dates for 2025-26

Provisional tax for the 2025-26 income year is typically paid in three equal instalments. If your balance date is 31 March (the standard NZ balance date), the instalment dates are:

These dates apply under the standard uplift method and ratio method. If you use AIM (Accounting Income Method) software, you pay when you file each period’s accounting data — typically monthly or two-monthly.

Calculating Your Provisional Tax

Under the standard uplift method, each instalment is one-third of 105% of your prior year’s residual income tax (or 110% if you are two years ago’s RIT is used). Under the estimation method, you estimate what your current year’s RIT will be and pay one-third of that at each instalment.

Getting instalments significantly wrong can trigger use-of-money interest (UOMI) on underpaid amounts. IRD currently charges interest at 8.97% per annum on underpayments (effective from 16 January 2026, down from 9.89%). Credit interest is paid to taxpayers at 2.25% per annum on overpayments. Both rates are reviewed periodically by IRD to track market rates, so confirm the current figure at IRD — interest on overpayments and underpayments before relying on it for a large balance.

Terminal Tax

Terminal tax is the final top-up payment for the 2025-26 year — the difference between what you have already paid in provisional tax and what you actually owe.

If your actual tax liability for 2025-26 is less than your provisional tax payments, IRD will refund the overpayment — usually by direct credit to your bank account.

GST Filing Dates

GST filing frequency depends on your turnover:

There are two statutory exceptions to the 28th-of-the-following-month rule: a taxable period ending 31 March is due 7 May, and a period ending 30 November is due 15 January.

Key GST periods ending during the 2025-26 tax year (two-monthly filers on the March-aligned cycle):

Use our GST calculator to quickly calculate GST amounts for your invoices and returns.

PAYE Employer Obligations

Employers filing PAYE are on their own schedule, but key dates affecting the 2025-26 year include:

• Payday filing: Employers must file employment information with IRD within two working days (for electronic filers) of each payday throughout the year
• Employer monthly schedule: Small employers using paper filing submit by the 20th of the following month

KiwiSaver and Employee Contributions

• KiwiSaver and PAYE contributions are remitted to IRD on the same payday schedule as PAYE filing
• Government contribution payment for the 2025-26 KiwiSaver year (1 July 2025 – 30 June 2026): IRD pays by 15 August 2026

FBT (Fringe Benefit Tax)

Late Filing and Late Payment Penalties

Late filing penalties

If you are required to file an IR3 or IR4 and miss the deadline, IRD charges a flat late filing penalty set by your net income for the year (Tax Administration Act 1994, s 139A(3)):

IRD must give you at least 30 days’ notice before imposing the penalty, so a return filed promptly after the reminder is not penalised. IRD initially charges the $50 amount and adjusts it once your return shows your actual net income.

Late payment penalties

Late payments incur:

• 1% penalty on the day after the due date
• 4% penalty on the amount remaining unpaid at the end of the seventh day after the due date, calculated on the tax plus that 1%

The old 1% per month incremental penalty no longer applies to income tax or provisional tax for the 2017-18 and later income years, or to GST periods ending after 31 March 2017 — it still applies to other tax types and to older debt.

On a $10,000 underpayment you would owe $100 the day after the due date (1%), then a further $404 at day seven (4% of the now-$10,100 owing) — $504 in penalties, after which only use-of-money interest keeps accruing. Work out your own figure with the late filing penalty calculator.

Planning Tips

1. Diarise all three provisional tax dates — missing the August date is the most common oversight because it falls early in the year
2. Review your prior-year RIT in April — determine whether your income has grown significantly, which may mean the standard uplift underestimates your liability
3. Register with a tax agent before 31 January — this gives you access to the extended return deadline of 31 March 2027
4. Set up direct debit — IRD’s direct debit facility means you can schedule provisional tax payments in advance so deadlines are met automatically
5. Calculate asset depreciation before EOFY — Use our depreciation calculator to work out your eligible deductions before the 31 March year-end.

Summary

Key dates at a glance for the 2025-26 year: