GST Registration in NZ: When You Have to, When You Should, How to Do It

GST is a 15% tax on most goods and services sold in New Zealand. If your business is registered, you charge GST on what you sell, claim back the GST you pay on business expenses, and file returns with the IRD. The decision to register isn't always voluntary — there's a turnover threshold that triggers compulsory registration.

This guide is educational only. Your numbers, your supply chain, and your customer base all matter. Treat this as the framework for your conversation with a chartered accountant, not a substitute for one.

When GST registration is compulsory

Under the rules in effect 2026, you must register for GST if either of these is true:

• Your business turnover (excluding GST) was over $60,000 in the past 12 months, OR
• You expect your turnover to exceed $60,000 in the next 12 months

The $60,000 figure is gross turnover, not profit. It includes all your taxable supplies — GST-applicable sales — even if your costs eat most of that.

If you cross the threshold mid-year, you have 21 days to register. Missing the deadline doesn't undo the GST you should have charged — the IRD can claim it from you anyway.

When voluntary registration makes sense

Even if you're under $60,000, you can register voluntarily. It's worth doing if any of these apply:

• Your customers are mostly GST-registered businesses (they claim the GST back, so charging it doesn't cost them anything)
• Your input costs include large GST-bearing expenses (you can claim GST credits)
• You're investing in equipment or stock now to support a growing business
• You want to look bigger to your customers (some take "GST registered" as a sign of professionalism)

Voluntary registration is harder to walk back later — you must stay registered for at least two years before deregistering.

When voluntary registration doesn't help

If your customers are mostly the general public — direct consumers — voluntary GST registration usually makes you more expensive than your competitors who aren't registered. Adding 15% to your price isn't a tax you absorb; it's a price increase your customer feels.

Based on these inputs, if 80%+ of your customers are individuals (not businesses), staying under the threshold and not registering voluntarily often nets you more take-home than registering does.

Filing frequency: monthly, two-monthly, six-monthly

When you register, you choose how often you file:

Frequency	Who can use it	Cash flow effect
Monthly	Anyone, mandatory if turnover > $24m	Tighter cash, faster refund cycle
Two-monthly	Default for most	Standard for established businesses
Six-monthly	Turnover under $500k	Easiest for small operators

For most small businesses, six-monthly is the lightest-touch option — two filings a year instead of six. The trade-off is that if you're due GST refunds (e.g., you're investing in equipment), you wait longer to get them back.

The practical registration steps

1. Get a myIR account if you don't already have one
2. Inside myIR, choose "Register for GST"
3. Provide your IRD number, business start date, expected turnover, and chosen filing frequency
4. Choose accounting basis: payments basis (you account for GST when money moves) or invoice basis (when invoices are issued — usually for businesses with turnover over $2 million)
5. Wait for IRD confirmation, usually within 10 business days

Once registered, every invoice you issue must include your GST number, the GST amount, and a clear statement that GST is included. Every business expense you claim a GST credit on must be backed by a tax invoice meeting the IRD's requirements.

What you actually do each filing period

At the end of each filing period:

• Total your taxable sales (output GST)
• Total your business expenses you have tax invoices for (input GST)
• Pay the difference to IRD, OR claim the difference back if input exceeded output
• File the return through myIR by the 28th of the month following the period (with some exceptions for January and May)

Late filing or late payment attracts penalties and use-of-money interest. The IRD doesn't usually start with prosecution for first-time small misses, but the costs add up fast if you ignore them.

What to do next

If you're approaching $60,000 turnover, the question isn't whether to register — it's when. Register before you cross the threshold to avoid the 21-day scramble. If you're well under and most of your customers are consumers, hold off and review every six months.

Talk to a chartered accountant before voluntary registration if your business model is unusual (exports, mixed-use assets, second-hand goods). The default rules don't always fit, and the wrong call here costs real money.

This is educational content, not personalised tax advice. For your situation, talk to a qualified NZ accountant.