NZ Company GST Filing Periods: Monthly, 2-Monthly or 6-Monthly?

Choosing a GST Filing Period: What Every New NZ Company Director Needs to Know

When you register your new NZ company for GST, Inland Revenue will ask you to select a filing period. This decision affects your cash flow, compliance burden, and the timing of GST refunds. Most new directors pick 2-monthly without thinking about it - but the right answer depends on your business model.

The Three GST Filing Options

Monthly Filing (Every Month)

You file and pay GST every month. Returns are due by the 28th of the following month (or the next business day if the 28th falls on a weekend or public holiday).

Best for:

• Companies with high GST input credits (you regularly buy GST-inclusive goods and claim more back than you charge - e.g. construction companies buying materials)
• Companies with large GST liabilities that benefit from disciplined monthly cash reserving
• Businesses with turnover above NZ$24 million (required by IRD)

Downside: 12 returns per year. More compliance work, though accounting software makes this manageable.

Two-Monthly Filing (6 Times Per Year)

The most common choice for NZ SMEs. You file every two months, with returns due by the 28th of the month after the filing period ends.

Best for:

• Most service-based businesses with relatively even turnover
• Companies where GST timing is not a significant cash flow issue

Downside: If you are regularly in a GST refund position (more inputs than outputs), waiting 2 months to reclaim means a larger working capital cost than monthly filing.

Six-Monthly Filing (Twice Per Year)

Available to companies with annual taxable supplies under NZ$500,000. You file twice per year, with periods ending March 31 and September 30 (returns due by April 28 and October 28).

Best for:

• Small businesses with consistent monthly cash flow and no seasonal peaks
• Businesses where the owner handles their own bookkeeping and wants minimal compliance touchpoints

Downside: You pay a large lump sum twice per year. If you have not been setting aside GST each month, this can create a cash crisis. Also, IRD does not allow you to choose this option if your annual turnover is above NZ$500,000.

The GST Ratio Option (For Some Taxpayers)

If you use the ratio option (income tax instalment basis), your GST payments are calculated as a percentage of your income tax instalments rather than based on actual GST collected. This can smooth out GST payments for highly seasonal businesses. Most NZ accountants do not recommend this for new companies - it adds complexity without proportional benefit until you have at least one full year of trading history.

Cash Flow Tip: Reserve GST Separately

Regardless of which filing period you choose, set up a separate bank account and transfer the GST component of every invoice you receive into it immediately. Do not touch it. Many NZ company failures in years 1-3 involve GST liabilities that were spent on operations. IRD treats unpaid GST as a priority debt and can move quickly to appoint a receiver.

Changing Your Filing Period

You can ask IRD to change your GST filing period at the start of any new period. Log in to myIR and request the change. It takes effect from the next filing period. There is no penalty for changing.

When Should a New Company Register for GST?

GST registration is compulsory when your turnover crosses NZ$60,000 in a 12-month rolling period. However, many new companies register voluntarily from day one because:

• They can immediately claim back GST on business setup costs (laptop, software, professional fees)
• It signals credibility when dealing with other GST-registered businesses
• Avoiding the administrative scramble of compulsory registration mid-year

See our related guide: NZ Company GST Registration Threshold Guide 2026.

For Accountants: Reaching New Companies Before the GST Registration Decision

The GST registration decision - compulsory vs voluntary, monthly vs 2-monthly vs 6-monthly - is typically made in the first month after incorporation. Companies that get good advice at this point make the right choice and start a long accountant relationship. Companies that wing it sometimes end up in a mess that requires expensive remediation.

FreshFirms alerts NZ accountants and bookkeepers the moment new companies register in their region, so they can have this conversation early. Start a free 7-day trial.