Every NZ company must file an annual income tax return (IR4) with Inland Revenue, even if the company made a loss or had no income. This guide walks through what the IR4 requires, how to prepare it, and how to file through myIR.
The IR4 is the annual company income tax return. File by 7 July (no tax agent) or 31 March of the following year (with a registered tax agent). The IR4 includes total income, deductions, taxable income, and tax payable at 28%. Most companies use an accountant — the IR4 requires financial statements and is more complex than a personal return. File through myIR or via an agent. Late filing penalty is $250.
IR4 Due Dates
| Situation | IR4 due date |
|---|---|
| No registered tax agent | 7 July |
| Registered tax agent | 31 March of the following year |
| Company balance date other than 31 March | Different dates apply — check with IRD |
Most small companies use March balance dates (financial year ends 31 March). If your company has a different balance date (e.g., 30 June or 31 December), your IR4 due dates shift accordingly.
What the IR4 Requires
The IR4 is a multi-section return covering:
1. Income
- Trading income (gross revenue from your business)
- Interest income received
- Dividend income received (with imputation credits)
- Rental income
- Other income sources
2. Deductions
- Cost of goods sold
- Salaries and wages (including shareholder-employee salaries)
- Interest expense (on business loans)
- Rent and premises costs
- Depreciation (on business assets)
- Professional fees
- Marketing and advertising
- Insurance
- All other deductible business expenses
3. Taxable Income
Revenue − deductions = taxable income
4. Tax Calculation
Taxable income × 28% = income tax payable
5. Less: Credits
- Provisional tax paid during the year
- Imputation credits received on dividends
- RWT credits (from interest income)
6. Net Tax to Pay (or Refund)
Financial Statements Required
Most companies must prepare financial statements before completing the IR4:
- Profit and Loss Statement (or Income Statement)
- Balance Sheet (Statement of Financial Position)
These are produced by your accountant (or accounting software like Xero/MYOB). The IR4 summary figures come from these statements.
For companies with turnover under $1 million, you may also need to file an IR10 (Financial Statements Summary) if your accounts are not otherwise submitted to IRD.
Common Deductible Expenses
| Expense | Deductible? | Notes |
|---|---|---|
| Staff wages and salaries | Yes | Including shareholder salary |
| Rent / lease costs | Yes | Business premises only |
| Interest on business loans | Yes | Not on capital |
| Depreciation | Yes | On assets at IRD rates |
| Motor vehicle costs | Yes | Business use proportion |
| Repairs and maintenance | Yes | Not capital improvements |
| Advertising and marketing | Yes | All legitimate marketing |
| Software and subscriptions | Yes | Business tools |
| Travel (business) | Yes | With documentation |
| Meals and entertainment | Partial | 50% only |
| Home office costs | Yes | Proportion of actual use |
Depreciation in Company Accounts
Business assets (computers, vehicles, equipment, fit-out) are not fully expensed in year 1 — they are capitalised and depreciated over their useful life at IRD-approved rates.
Key rules:
- Assets under $1,000 (excluding GST) can be immediately expensed (low-value asset write-off)
- Assets over $1,000 are depreciated over their useful life
- Building depreciation was removed for residential buildings in 2011 but remains for commercial buildings
- Depreciation reduces taxable income each year
Provisional Tax and the IR4
When you file the IR4, you compare:
- Residual income tax (RIT): Tax payable after all credits
- Provisional tax paid during the year: Three instalments
If provisional tax paid < RIT = terminal tax to pay (due 7 April or 7 February) If provisional tax paid > RIT = refund (credited to your account)
How to File the IR4
Option 1: Via an accountant (most common) Your accountant prepares the IR4 from your financial statements and files it on your behalf via IRD’s gateway services. If they are a registered tax agent, your due date extends to 31 March.
Option 2: Via myIR directly
- Log in to myIR → Switch to your company’s account
- Income tax → File a return → IR4
- Work through the income and deductions sections
- Submit
For complex companies, DIY filing is not recommended without accounting knowledge.
Frequently Asked Questions
Does a dormant company need to file an IR4?
Yes — all registered NZ companies must file an IR4, even if they had no activity. A nil return is still required. Failure to file results in a $250 late filing penalty.
What if I cannot pay the tax owed by the due date?
File the IR4 on time regardless. Contact IRD to arrange a payment plan. A late IR4 filing incurs a $250 penalty; failing to pay incurs late payment penalties and use-of-money interest.
Can I claim a loss carry-back?
Yes — since COVID-era legislation, NZ companies can carry back losses to the immediately prior year (subject to continuity of ownership rules). This can generate a refund of prior-year tax paid.