How to File Your NZ Tax Return (IR3): Step-by-Step Guide
A step-by-step guide to filing an IR3 individual tax return in New Zealand — who needs to file, what information you need, and key deadlines.
Published 5 February 2026
Most New Zealand salary and wage earners don’t need to file a tax return — IRD handles their tax through PAYE. But if you earn income outside of regular employment, you’ll likely need to file an IR3 individual tax return. Here’s how.
Who Needs to File an IR3?
You must file an IR3 if you earned any of the following during the tax year:
- Self-employment or business income
- Rental property income
- Overseas income (including foreign investments)
- Partnership or look-through company income
- Shareholder-employee salary from a close company
- Estate or trust income not already taxed
- Income from taxable property sales (e.g., bright-line rule)
If you only earned salary/wages and interest or dividends, IRD usually issues an automatic income tax assessment — you don’t need to file.
Key Deadlines (2025-26 Tax Year)
| Deadline | Date |
|---|---|
| Tax year ends | 31 March 2026 |
| IR3 due date (without tax agent) | 7 July 2026 |
| IR3 due date (with tax agent) | 31 March 2027 |
| Terminal tax due | 7 February 2027 (or 7 April 2027 with tax agent) |
Using a registered tax agent gives you a significant extension on filing and payment deadlines.
What Information You Need
Before starting your IR3, gather:
- IRD number
- Income summaries from employers (available in myIR)
- Bank interest certificates and dividend statements
- Records of self-employment income and expenses
- Rental property income and expense records
- Any overseas income details
- Donation receipts (for tax credits)
- Records of any tax already paid (e.g., provisional tax, RWT)
Step-by-Step: Filing Online
1. Log In to myIR
Go to my.ird.govt.nz and log in with your myIR credentials. If you don’t have an account, you’ll need to register first.
2. Start Your IR3
Navigate to the income tax section. IRD pre-fills information it already holds — salary, interest, dividends, and PAYE paid.
3. Add Other Income
Enter any income not pre-filled:
- Self-employment net profit (from your financial statements)
- Rental income (total rent received minus allowable expenses)
- Overseas income (converted to NZD)
- Any other taxable income
4. Claim Deductions and Credits
Add eligible deductions such as:
- Income protection insurance premiums
- Donation tax credits
- Independent earner tax credit (if applicable)
5. Review and Submit
Check all figures carefully. The system calculates your tax liability and compares it to tax already paid. You’ll see whether you have tax to pay or a refund due.
6. Pay Any Tax Owing
If you owe terminal tax, pay by the due date to avoid interest and penalties. Payment options include direct debit, bank transfer, or credit card through myIR.
Common Mistakes to Avoid
- Missing income sources: IRD receives information from banks and employers — they’ll know if you’ve left something out
- Claiming non-deductible expenses: Personal expenses, commuting costs, and capital expenditure generally aren’t deductible
- Late filing: Penalties apply for late returns, starting at $50 and increasing over time
- Incorrect overseas income conversion: Use the IRD-approved exchange rates for converting foreign income