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NZ GST Filing Frequency: Six-Monthly, Two-Monthly, Monthly

17 October 2026 · Guide · Not tax advice

Short answer: according to Inland Revenue (IRD), you choose your GST filing frequency when you register, and you can change it in myIR to another frequency you are eligible for. Six-monthly is for businesses with sales under $500,000 in any 12-month period; two-monthly is for sales under $24 million; monthly is required if sales are over $24 million (and anyone can choose monthly).

Match your balance date

IRD says your GST filing periods should align with your income tax balance date, usually 31 March. With a 31 March balance date, two-monthly filers file for periods ending in odd months (May, July, September, November, January, March) and six-monthly filers for periods ending 30 September and 31 March.

How to change

IRD says you can change your filing frequency in myIR, to one you are eligible for. SPS 17/02 says IRD notifies you in writing of the approved frequency and the start date, so wait for that confirmation before switching (our reading of the SPS).

When you must change

If your sales in any 12-month period change, you may no longer be eligible. IRD's standard practice statement SPS 17/02 (in force since 4 October 2017) says sales are measured excluding GST. If you become ineligible because your sales exceed $500,000 and you are not a seasonal filer, the SPS says to notify IRD within 21 days of the breach; it also says that a one-off breach does not force a change if you expect to stay under $500,000 over the next 12 months. The SPS has a second wording, under which turnover is checked when you file a return and you notify IRD if you expect it to continue; follow the one IRD confirms to you.

Seasonal six-monthly criterion

A business can also apply for six-monthly filing above $500,000 if 80% or more of its taxable supplies in an income year are made in a six-month period that ends on a day in the last month of its income year, and it has not used this seasonal criterion in the previous 24 months (SPS 17/02).

Example (made-up numbers)

A sole trader with 31 March balance date has $420,000 of sales and files six-monthly. A big contract lifts her 12-month sales to $540,000 and she expects that to continue. She would be expected to tell IRD and move to two-monthly filing.

Related

GST registration and filing dates; tax calendar.

FAQ

Is six-monthly better? IRD says it suits businesses with few sales and purchases, but accounting for six months at once can be a big job.

Can I pick any date? The period must align with your balance date.

What we could not verify

• Whether SPS 17/02 (dated 2017) has since been replaced: the current IRD pages read do not cite it.
• IRD's GST guide IR375 was only seen as a search extract; this page makes no claim based on it, such as the default frequency or the wait-for-confirmation rule.
• Whether thresholds change after October 17, 2026.
• The effect on payment dates and interest when you change period.

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