Terminal Tax Due Date Calculator NZ 2026/27

Worked examples

Example 1, standard balance date, no tax agent: Aroha is a self-employed physiotherapist with the standard 31 March balance date. She files her own return and does not use a tax agent. For the 2025/26 tax year, which ended 31 March 2026, her terminal tax nominally falls due 7 February 2027. Because 7 February 2027 is a Sunday, Inland Revenue moves her actual due date to Monday 8 February 2027.

Example 2, standard balance date, with a tax agent: Michael, a self-employed builder, has the same 2025/26 tax year, but works with a registered tax agent who holds a current extension of time arrangement. His terminal tax is due 7 April 2027 instead, a Wednesday, so no weekend adjustment applies. That gives him almost two extra months beyond Aroha's date to finalise his accounts and pay.

Example 3, non-standard balance date: Southern Fisheries Ltd has Inland Revenue approval to use a 30 June balance date instead of the standard 31 March, to align with an overseas parent company's year end. Because 30 June falls between 31 March and 30 September, it is grouped with the standard 31 March cohort, so for its year ended 30 June 2026 its terminal tax without a tax agent is nominally due 7 February 2027. That date is a Sunday, so the actual payment date moves to Monday 8 February 2027. With a tax agent's extension of time it would instead be 7 April 2027. Because non-standard balance dates can carry individually agreed schedules, the company still confirms this date in myIR before relying on it.

What terminal tax actually is

Terminal tax is the final settling-up between what you actually owed in income tax for the year and what you had already paid along the way, whether that was through PAYE deducted from wages, provisional tax instalments, or withholding tax on schedular payments. If your prepayments added up to less than your final tax bill, the shortfall is your terminal tax payment, due on your terminal tax date. If you prepaid more than you owed, you receive the difference back as a refund instead. Terminal tax applies whether or not you were required to pay provisional tax during the year, since anyone with an income tax return can end up owing, or being owed, money once the year is finalised.

The terminal tax date is not the same as your filing deadline

A common source of confusion is treating the return filing deadline and the terminal tax due date as the same thing. They are not. If you file your own return without a tax agent, Inland Revenue requires it to be filed by 7 July following the end of the tax year. The terminal tax due date, the date your actual payment or refund is settled, falls much later, on 7 February of the year after that. In practice this means most self-filers finish and file their return in the middle of the year, then have several more months before the tax itself needs to be paid. Building your return earlier does not bring your payment date forward, and leaving your return until closer to July does not push your payment date back either. The two dates are set independently.

How a tax agent changes your terminal tax date

Registered tax agents can hold what Inland Revenue calls an extension of time, or EOT, arrangement, which lets the agent spread their whole client list's return filing across the year instead of everyone filing by 7 July. When you are linked as a client to an agent with a current EOT arrangement, your own terminal tax due date generally moves from 7 February to 7 April, two extra months. This is one of the most concrete, quantifiable reasons small business owners and contractors use a tax agent or an accounting service instead of filing solo: it is not just about getting help with the numbers, it directly extends the calendar. If you already have a tax agent and are not sure whether your EOT is currently active, for example if you changed agents partway through the year, ask your agent to confirm, since the terminal tax date only extends while a valid arrangement is in place.

What happens if you miss your terminal tax date

Tax that remains unpaid after your terminal tax due date starts attracting use of money interest, which Inland Revenue calculates daily and which compounds over time, and can also attract separate late payment penalties on top of that interest. The longer a balance sits unpaid, the more it grows, so the cost of missing the date by a few weeks is meaningfully different from missing it by several months. If you know in advance that you cannot pay in full, contacting Inland Revenue before the due date to arrange an instalment plan is generally far better than paying late with no arrangement in place, since a plan can reduce or stop further penalties even though interest still applies. Our Use of Money Interest Calculator lets you estimate what a specific overdue amount could cost over time.

Non-standard balance dates

Most individuals, sole traders and small companies use the standard 31 March balance date, but some businesses, often those with an overseas parent company or a seasonal trading pattern, have Inland Revenue approval to use a different balance date instead. For terminal tax, Inland Revenue groups balance dates into two camps. Balance dates from 31 March to 30 September are treated like the standard 31 March cohort, so their terminal tax is due 7 February the following year, or 7 April with a tax agent, exactly as it is for a 31 March filer. Balance dates from 1 October to the end of February instead fall due on the seventh day of the eleventh month after the balance date, or the thirteenth month with a tax agent. This calculator applies those rules to whichever balance date you choose. That said, Inland Revenue can and does set individual schedules for some non-standard balance dates, so treat the result here as a strong estimate and confirm your exact date in myIR or with your tax agent before relying on it for a large payment.

What this calculator assumes

• Your terminal tax date follows the standard Inland Revenue pattern of 7 February without a tax agent, or 7 April with a tax agent holding a current extension of time arrangement, for a 31 March balance date.
• For other balance dates, the same general 11-month and 13-month rule is applied, consistent with this site's Provisional Tax Due Date Calculator.
• A due date falling on a Saturday or Sunday is moved forward to the following Monday, matching Inland Revenue's confirmed approach.
• Public holidays are not modelled, since that requires a full calendar for each specific year, so confirm your exact date in myIR if it falls close to Waitangi Day, Easter or another holiday.
• Non-standard balance date schedules can be set individually by Inland Revenue, so the figure shown for a non-standard balance date is a strong estimate, not a guarantee.

Who this calculator is for

This calculator is for anyone who needs to know exactly when their New Zealand terminal tax payment is due: self-employed people and contractors, small business owners, landlords with rental income, and the accountants and bookkeepers who manage due dates on their behalf. It is equally useful for working out what having a tax agent's extension of time is actually worth in extra time, for checking a date already given to you by an accountant or software package, and for planning ahead so a tax bill never arrives as a surprise.

Related calculators

• Provisional Tax Due Date Calculator: your provisional tax instalment dates through the year, alongside the same terminal tax logic.
• Provisional Tax Calculator: the actual instalment amounts to pay under the standard, estimation and AIM methods.
• Terminal Tax Calculator: the wash-up amount itself, what you owe or are owed once the year is finalised.
• Use of Money Interest Calculator: what a late or underpaid terminal tax payment could cost in interest and penalties.
• Tax Reserve Per Invoice Calculator: how much to set aside from every invoice so your terminal tax payment is never a scramble.

Official NZ sources

This calculator is built from primary New Zealand sources. Always confirm current figures against the official source for your situation:

• Inland Revenue (IRD): 7 February terminal tax reminder
• Inland Revenue (IRD): extension of time arrangements for tax agents
• Inland Revenue (IRD): income tax overview