IR3 Return Explained: Filing as Self-Employed in NZ (2026)

Short answer: Self-employed people in New Zealand file an IR3, the individual income tax return. For the 2026 tax year (1 April 2025 to 31 March 2026) it is due 7 July 2026 if you have no tax agent, and you file it in myIR or on paper. Your business profit goes in one place — Box 24, self-employed net income — usually with an IR10 financial statements summary attached. Tax to pay is due 7 February 2027.

The IR3 is not a business return. It is your personal tax return, and your business result is one line inside it. Every figure below comes from the IR3 2026 form, the IR3 guide (IR3G) or Inland Revenue’s own website, and applies to a sole trader with a standard 31 March balance date. Rates and dates move: check anything you are about to act on against IRD before you file. For the rates and thresholds behind the numbers you enter, see self-employed taxes in NZ; for what counts as a deductible cost, see expenses and receipts.

What is an IR3 return, and do I have to file one?

The IR3 is titled “Individual tax return”. The 2026 edition covers 1 April 2025 to 31 March 2026 — Inland Revenue names a tax year by the date it ends, so the “2026 tax year” is the one that finished this March.

You must file if you received more than $200 before tax of income Inland Revenue has not already been told about, even if that was only for part of the year. It is not a profit threshold, so a sole trader who broke even or made a loss still files. The IR3 guide also lists self-employed income, rental income and overseas income as reasons to file in their own right, so the $200 line is a floor rather than the only trigger. Wages, benefits and most bank interest are already reported to IRD by the payer; your invoicing income is not.

You use your personal IRD number. A sole trader does not get a second number for the business. If yours is an older 8-digit number, the form is explicit: it starts in the second box, which amounts to adding a leading zero.

When is my IR3 due, and when should I actually file it?

Situation	2026-year IR3 (year ended 31 March 2026)
No tax agent, no extension of time	7 July 2026
Client of a tax agent with a valid extension of time	31 March 2027

The instruction printed on the form reads: send us your return by 7 July 2026, unless you have an extension of time or a non-standard balance date. Non-standard balance dates exist but need IRD approval, and almost no sole trader has one.

The date to file and the date you should file are different. If anyone who paid you has to report those payments to Inland Revenue — an employer, a bank, a portfolio investment entity — that information does not land until well into May. IRD’s own guidance is that if anyone who paid you has to report those payments, you need to wait until June to file. A return started in April is built on an incomplete pre-populated income picture in myIR, and correcting it afterwards is more work than waiting.

How do I file an IR3 — myIR or on paper?

Three routes exist.

• myIR. Inland Revenue’s secure online portal. Salary, interest and schedular payment totals are pre-populated from what third parties have reported, and you fill in the rest. IRD states that returns completed in myIR are usually processed faster.
• Paper. Print the IR3, complete it and post it to Inland Revenue, PO Box 39090, Wellington Mail Centre, Lower Hutt 5045. Keep a copy.
• Through a tax agent or approved software. This is the route that carries an extension of time, which is the practical reason most self-employed people use an accountant.

There is no separate sole trader portal. myIR is the system for everything: the IR3, GST returns, provisional tax and payments.

Which parts of the IR3 does a self-employed person fill in?

Most of the form is questions you will answer “No” to. These are the boxes that matter to a one-person business.

Box	What it asks	What you do with it
1	IRD number	Your personal number; 8-digit numbers start in the second box
6	Business industry classification (BIC) code	The code for your trade, looked up at businessdescription.co.nz
8	Bank account	Where any refund is paid by direct credit
12A–12D	Schedular payments	Gross payments, tax already deducted, and related expenses at 12C
24	Self-employed net income	Your business profit for the year
28	Total income	Adds the income subtotal and Boxes 22H, 23, 24, 25B, 26 and 27
29	Other expenses claimed	Only costs not already claimed elsewhere in the return
30	Income after expenses	Box 28 minus Box 29
31	Net losses brought forward	Losses carried in from earlier years
32	Taxable income	Box 30 minus Box 31B
36A	Residual income tax	The figure that decides next year’s provisional tax
39	2027 provisional tax	Asks whether Box 36A is a debit of more than $5,000
42	Declaration	Also your statement of earnings for ACC purposes

Question 42 is worth reading rather than skimming. The declaration says the return is true and correct and is also a correct statement of your earnings under the Accident Compensation Act 2001. That is why an ACC invoice arrives weeks after you file: Inland Revenue passes your figures across.

How does my business profit get onto the return?

It arrives as one number at Box 24. Everything that produces that number happens before you open the form.

Net profit is your business income for the year less the expenses incurred in earning it, apportioned where there is private use. Vehicle claims have their own regime and their own arithmetic — kilometre rates and vehicle expenses covers the two-tier method and the logbook alternative.

Because Box 24 is a single figure, Inland Revenue asks for the workings alongside it. IRD lists a Financial statements summary (IR10) among the extra forms you may need for untaxed income from your business — in myIR it goes on as a secondary form; on paper you print, sign and attach it. The IR10 is a short-form set of accounts, and IRD’s own instruction is to “speed up the processing of your tax return” by completing one; use it and IRD does not need a set of accounts. It is not the only option — the IR3 guide says you can instead work from your own financial records or use the Business income (IR3B) schedule — but you still have to prepare and keep full accounts either way.

Watch the double-claim trap. Expenses already taken into account in your Box 24 profit must not be repeated at Box 29, and the form says so twice. Box 29 is for costs that have not been claimed anywhere else — the fee you paid someone to complete the return is the classic example.

What if tax was already deducted from my contracting income?

Contractors on schedular payments have tax withheld at source, at the rate elected on an IR330C. That does not remove the obligation to file — it changes where the income sits on the return.

Schedular payments go to Question 12, not Question 24: gross payments at 12B, tax already deducted at 12A, expenses related to those payments at 12C, and the net figure at 12D. If you have both withheld contract work and direct-invoiced work, they land in different places on the same return. Invoicing as a contractor in New Zealand covers what those invoices have to show. If you pick your own rate on the IR330C it has to be at least 10% when you are a New Zealand tax resident (15% for a non-resident on a temporary work or entry visa), and anything lower needs a tailored tax rate certificate. A rate elected near that 10% floor rarely matches a real marginal rate once ACC and the higher bands are added, which is why withheld contractors still commonly have tax to pay in February.

When and how do I pay the tax?

Filing and paying are separate events with separate dates. Filing on 7 July does not mean paying on 7 July.

Payment	Date
End-of-year (terminal) tax for the 2026 year, no tax agent	7 February 2027
Terminal tax, tax agent clients with a valid extension	7 April 2027
2027 provisional tax, standard option, first instalment	28 August 2026
Second instalment	15 January 2027
Third instalment	7 May 2027

Those dates all come from Inland Revenue’s tax due date calendar for 2026-27 (IR328). One wrinkle: 7 February 2027 falls on a Sunday, and the same calendar shows Waitangi Day (Saturday 6 February) observed on Monday 8 February. IRD’s rule is that a due date landing on a weekend or public holiday can be met on the next business day without penalty — which here points to Tuesday 9 February 2027, not the Monday. Check the due date shown in your own myIR account before you rely on it.

Question 39 is the provisional tax trigger. If Box 36A is a debit of more than $5,000, you may have to pay 2027 provisional tax, and you print the option used at 39A — S for standard, E for estimation, R for ratio. Question 38A lets you push a refund straight across to that provisional tax instead of taking the cash.

To pay, use myIR, your bank’s “pay tax” function, or one of the other methods listed on Inland Revenue’s ways of paying page. If the bill is more than you can meet, an instalment arrangement can be set up in myIR — arranging one before the due date beats missing it, because use-of-money interest runs on underpaid tax from the day after it was due.

One relief is easy to miss. Question 37 asks about the early payment discount. The rate is no longer fixed: from the 2025 income year Inland Revenue sets it as the use-of-money interest credit rate at 31 March of the previous tax year plus 2%. IRD’s published rates are 6.30% for the 2026 income year and 4.25% for the 2027 income year — check the current figure on IRD’s paying tax in your first year in business page before you count on it.

To qualify you must be self-employed, a partner in a partnership or an owner of a look-through company, get most of your income from the business, make a voluntary income tax payment before the income year ends (or use tax pooling funds), have no obligation to pay provisional tax in that year or in any of the 4 years before, and apply on or before the date your return has to be filed. It exists specifically to soften the year-two collision of last year’s tax and this year’s instalments.

What happens if I file the IR3 late?

Filing late without an extension of time can attract a late filing penalty, charged on top of any interest on unpaid tax.

Net income	Late filing penalty
Less than $100,000	$50
$100,000 to $1 million	$250
More than $1 million	$500

The penalty is charged at $50 initially and adjusted once the return is filed and your actual net income is known. The amounts are small next to the interest on an unpaid balance, but an unfiled return also means an unknown liability, and that is the one you fail to save for. If you know you will miss the date, apply for an extension before 7 July rather than after.

What records sit behind the return, and where does Keel fit?

Box 24 is one number, but Inland Revenue’s record keeping rule is that you keep all your records, electronic ones included, for at least 7 tax years — and that clock keeps running even if you stop trading. The IR10 is a summary; the invoices, receipts and trip logs underneath it are the evidence.

Keel: Invoice Maker & Receipts, by Ilura Technology OÜ, is built for that layer and nothing above it. It runs entirely on your iPhone: no account, no sign-in, no bank connection, no cloud sync. The App Store privacy label reads “Data Not Collected”.

The honest tradeoff is that nothing imports itself. There is no bank feed reconciling overnight — you create the invoice, you photograph the receipt (Apple Intelligence reads the merchant, total, tax and date on device), you log the trip. In exchange the records stay in your hands, the ledger is append-only and hash-chained, and at year end the Accountant Pack exports the whole year as a CSV plus a one-page summary PDF: the file your accountant turns into an IR10, or that you work from yourself in myIR.

The free tier gives you unlimited invoices, receipts and mileage, with a “Made with Keel” footer on invoices. Keel Pro is a one-time $249.99 Lifetime purchase, not a subscription. Keel: Invoice Maker & Receipts on the App Store.

Frequently asked questions

Do I have to file an IR3 if I am self-employed in New Zealand? Yes, if you received more than $200 before tax of income Inland Revenue has not already been told about. Invoiced business income is not reported to IRD by anyone else, so it meets that test almost immediately. The trigger is unreported income, not profit, so you file even in a year where the business made a loss.

When is the IR3 due for the 2026 tax year? 7 July 2026 for the year ended 31 March 2026, if you have no tax agent and no extension of time. Clients of a tax agent with a valid extension have until 31 March 2027. IRD suggests waiting until June to file, because employers and financial institutions report their information in May.

Which box on the IR3 do I put my business profit in? Box 24, self-employed net income, at Question 24. It takes your net profit for the year as a single figure. Do not include any income already shown on your Summary of Income there. You normally file a Financial statements summary (IR10) with the return to show how that profit was worked out.

Do I need to file an IR10 with my IR3? Inland Revenue lists a Financial statements summary (IR10) among the extra forms you may need for untaxed income from your business, and says completing one speeds up processing of your return. It is not strictly compulsory — the IR3 guide also lets you work from your own financial records or the IR3B business income schedule — but if you do file an IR10, IRD does not need a set of accounts as well. In myIR it is added as a secondary form; on paper you print, sign and attach it.

When do I pay the tax shown on my IR3? End-of-year tax for the 2026 year is due 7 February 2027 if you have no tax agent, or 7 April 2027 for tax agent clients with a valid extension. 7 February 2027 is a Sunday and Waitangi Day is observed on Monday 8 February, so the next business day rule moves the practical date on again — check yours in myIR. Filing in July does not mean paying in July. Pay through myIR, your bank’s pay tax function, or another method on Inland Revenue’s ways of paying page.

What is the penalty for filing an IR3 late in NZ? A late filing penalty of $50 where net income is under $100,000, $250 between $100,000 and $1 million, and $500 above that. It is charged at $50 first and adjusted once the return is filed. Use-of-money interest on any unpaid tax is separate and usually the larger cost.

---

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