Tax Year NZ: Key Tax Dates for Sole Traders (2026–27)

Short answer: The New Zealand tax year runs from 1 April to 31 March and is named after the year it ends, so the 2027 tax year is 1 April 2026 – 31 March 2027. For a sole trader the fixed dates are 7 July (IR3 due if you have no tax agent), 7 February (end-of-year tax due, or 7 April with a tax agent’s extension), 28 August, 15 January and 7 May (provisional tax), and the 28th of the month after each GST period. For the 2026 tax year, the IR3 was due 7 July 2026 and the tax is due 7 February 2027.

The tax dates here come from Inland Revenue: its timelines at the end of the tax year and the IR328 tax due date calendar for 2026–27. They assume the standard 31 March balance date. For what you owe on those dates, see self-employed taxes in NZ; for the return itself, the IR3 explained.

When does the tax year start and end in NZ?

The tax year starts on 1 April and ends on 31 March, and Inland Revenue names it by the year in which it ends, so “the 2026 tax year” is mostly 2025.

Tax year name	Runs from	To	IR3 due (no tax agent)
2025 tax year	1 April 2024	31 March 2025	7 July 2025
2026 tax year	1 April 2025	31 March 2026	7 July 2026
2027 tax year	1 April 2026	31 March 2027	7 July 2027

As of October 2026 you are trading in the 2027 tax year. ACC levy years follow the same cycle, so the 2026–27 levy year is the 2027 tax year. A business can apply for a non-standard balance date, which shifts every date below; if you have never asked for one, yours is 31 March.

When is the tax return due for 2026 and 2027?

Your IR3 is due 7 July after the tax year ends if you file it yourself, or 31 March of the following year if you are the client of a tax agent with an extension of time.

Tax year	IR3 due, no tax agent	IR3 due, tax agent with extension
2026 (year ended 31 March 2026)	Tuesday 7 July 2026	Wednesday 31 March 2027
2027 (year ending 31 March 2027)	Wednesday 7 July 2027	31 March 2028

Employers, banks and other payers report their figures after 31 March, so Inland Revenue suggests you wait until June to file. You file an IR3 if you received more than $200 of income Inland Revenue was not told about, which covers almost any invoiced business income, even in a loss year.

When do I get my tax refund in NZ?

If Inland Revenue already has all your income information, it works out your tax for you. Automatic income tax assessments start going out from the last weekend in May and continue into June and July. Inland Revenue’s refunds and tax bills page says refunds are paid from late May to the end of July, as each assessment is processed.

That timetable is for people whose income was all reported to Inland Revenue, such as employees. A sole trader files an IR3, and any refund follows once it is processed. With no PAYE taken from your invoices, a bill is more likely than a refund.

When is end-of-year (terminal) tax due?

Tax left to pay after your IR3, called end-of-year or terminal tax, is due on 7 February after the tax year ends, or 7 April if you have a tax agent with an extension of time.

Tax year	No tax agent	Tax agent with extension
2026	7 February 2027	Wednesday 7 April 2027
2027	7 February 2028 (Waitangi Day is observed that Monday, so pay by Tuesday 8 February)	Friday 7 April 2028

7 February 2027 is a Sunday, and Waitangi Day (Saturday 6 February) is observed on Monday 8 February. When a due date lands on a weekend or public holiday, Inland Revenue accepts payment on the next working day, which points to Tuesday 9 February 2027. Check the due date shown in your own myIR account before relying on the extra days.

Filing in July does not mean paying in July, but put the money aside early: the tax on $60,000 of profit at current tax brackets is $10,220.50.

What are the provisional tax dates?

On the standard option, provisional tax is paid in three instalments on 28 August, 15 January and 7 May, according to Inland Revenue’s payment dates for provisional tax. You pay it if your residual income tax in your last return was more than $5,000.

Instalment	2027 tax year	2028 tax year
First	Friday 28 August 2026	28 August 2027 (a Saturday, so Monday 30 August)
Second	Friday 15 January 2027	15 January 2028 (a Saturday, so Monday 17 January)
Third	Friday 7 May 2027	7 May 2028 (a Sunday, so Monday 8 May)

Different dates apply if you file GST six-monthly, use the ratio or AIM option, or have a non-standard balance date. Provisional tax in NZ explains the options and why year two of a business is the expensive one.

Key NZ tax dates from October 2026 to September 2027

The next 12 months for a sole trader in one table. GST rows show the common periods; GST due dates lists every monthly, two-monthly and six-monthly date.

Date	What is due	Who it applies to
Wed 28 October 2026	GST return and payment for periods ending 30 September	Monthly, odd-month two-monthly (Aug–Sep) and six-monthly (Apr–Sep) filers
Mon 30 November 2026	GST for periods ending 31 October (28 November is a Saturday)	Monthly and even-month two-monthly filers
Fri 15 January 2027	Second provisional tax instalment, 2027 tax year; GST for periods ending 30 November	Provisional taxpayers; monthly and odd-month two-monthly GST filers
7 February 2027 (pay by Tue 9 February)	End-of-year tax for the 2026 tax year	Anyone with 2026 tax to pay and no tax agent
Mon 1 March 2027	GST for periods ending 31 January (28 February is a Sunday)	Monthly and odd-month two-monthly filers
Wed 31 March 2027	2027 tax year ends; 2026 IR3 due for tax agent clients with an extension	Everyone; agent clients
Wed 7 April 2027	End-of-year tax for the 2026 tax year	Tax agent clients with an extension
Fri 7 May 2027	Third provisional tax instalment, 2027 tax year; GST for periods ending 31 March	Provisional taxpayers; monthly, odd-month two-monthly and six-monthly GST filers
Wed 7 July 2027	IR3 for the 2027 tax year	Self-employed people with no tax agent
Mon 30 August 2027	First provisional tax instalment, 2028 tax year (28 August is a Saturday)	Provisional taxpayers
Around September 2027	ACC CoverPlus invoices, based on your filed IR3	Self-employed people

The ACC invoice is not a tax due date, but it lands soon after the August instalment and catches people out; ACC levies for the self-employed has the rates.

What should I do before 31 March?

The end of the tax year is a records deadline more than a tax deadline. These are easier before 31 March than in June:

• Bring your invoices up to date. You or your accountant will need a clean list of everything you invoiced in the year and what was still unpaid on 31 March.
• File your receipts and expenses. Self-employed expenses and receipts lists what to keep.
• Close off your vehicle log if you claim business travel; see kilometre rates and vehicle expenses.
• Consider a voluntary payment if you are in your first year and not yet a provisional taxpayer. Inland Revenue’s early payment discount rewards paying before the year ends if you qualify, and its published rate for the 2027 income year is 4.25%.

Inland Revenue’s record keeping rule is that you keep all records, including electronic ones, for at least 7 years.

What happens if I miss a tax date?

A late IR3 can bring a late filing penalty of $50 where net income is under $100,000, and a late GST return $50 on the payments basis or $250 on the invoice or hybrid basis. Paying late usually costs more. Inland Revenue’s late payment penalties are 1% of the unpaid tax the day after the due date and a further 4% seven days later, and use-of-money interest runs on unpaid tax at 8.97% a year from 16 January 2026. If you cannot pay in full, file on time anyway and ask Inland Revenue for an instalment arrangement before the date passes.

Keeping a year’s records ready, and where does Keel fit?

Tax dates are only stressful when the records behind them are scattered. With invoices, receipts and trips already in one place on 31 March, each return is an afternoon, not a week.

Keel: Invoice Maker & Receipts, an iPhone app by Ilura Technology OÜ, keeps those records. You create quotes that become invoices in one tap, send PDF invoices, capture receipts and expenses, log business mileage, and keep each item under the job and customer it belongs to. “Who owes you” shows unpaid invoices and prepares reminder drafts that you review and send yourself; nothing is sent automatically. Records stay on your iPhone, with no account, no bank connection and no cloud sync, and the App Store privacy label reads “Data Not Collected”.

Keel does not track tax due dates, file your IR3 or GST returns, calculate the tax you owe or connect to Inland Revenue. It is free with no invoice limit (free invoices carry a small “Made with Keel” footer), and Keel Lifetime is a one-time purchase of $249.99 USD (the App Store shows your local price) that adds custom branding, signature, premium templates and accountant-ready exports and reports. Keel on the App Store. More guides are on the New Zealand hub.

Frequently asked questions

When does the tax year start and end in NZ? The New Zealand tax year starts on 1 April and ends on 31 March. Inland Revenue names it after the year it ends in, so the 2027 tax year runs from 1 April 2026 to 31 March 2027. A business can apply for a non-standard balance date, but almost every sole trader uses 31 March.

When is the tax return due in NZ for 2026? The IR3 for the 2026 tax year (1 April 2025 – 31 March 2026) was due 7 July 2026 if you have no tax agent. Clients of a tax agent with an extension of time have until 31 March 2027. Any tax to pay is due 7 February 2027, or 7 April 2027 with a tax agent.

When do we get our tax refund in NZ? If Inland Revenue has all your income information, it sends an automatic income tax assessment from the last weekend in May, and refunds are paid into your bank account between late May and the end of July. If you are self-employed, you file an IR3 instead, and any refund follows once that return is processed.

When is terminal tax due in NZ? End-of-year (terminal) tax is due 7 February after the tax year ends, or 7 April if you have a tax agent with an extension of time. For the 2026 tax year that is 7 February 2027, a Sunday followed by the observed Waitangi Day holiday, so payment by Tuesday 9 February 2027 is on time. Check the date in myIR.

Is the GST year the same as the tax year? GST has its own periods, monthly, two-monthly or six-monthly, each due on the 28th of the following month, except periods ending 30 November (due 15 January) and 31 March (due 7 May). If you file monthly, six-monthly with a 31 March balance date, or two-monthly on the cycle ending in odd months, your last GST period of the year ends on 31 March, in step with the tax year.

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This article is general information, not tax advice. Consult a qualified New Zealand tax professional.