GST Registration Threshold Calculator
This calculator checks your business turnover against New Zealand's $60,000 GST registration threshold, the point at which registering with Inland Revenue stops being optional and becomes compulsory. Because the rule under section 51 of the Goods and Services Tax Act 1985 is not a simple annual figure, the tool runs both tests Inland Revenue actually uses. The retrospective test looks at your actual taxable turnover over the past 12 months, and the prospective test looks at what you reasonably expect to earn over the next 12 months, either of which can trigger the obligation on its own. Enter your turnover for each period and the calculator instantly tells you whether registration is required now, and by how much headroom or excess you sit either side of the line. A third field lets a new or growing business enter a steady monthly turnover figure, which projects an annualised run-rate and estimates how many months of trading it would take to reach $60,000 in cumulative turnover, useful when you do not yet have 12 months of real figures behind you. It updates instantly as you type, with no submit button. This is built for sole traders, contractors, and small business owners deciding whether to register now, and for anyone weighing up voluntary registration below the threshold. Figures are indicative only, so confirm your specific position with Inland Revenue or your accountant before relying on it.
Legislation: Section 51 of the Goods and Services Tax Act 1985.
Two tests: Retrospective (turnover already exceeded $60,000 in the past 12 months) or prospective (reasonable grounds to expect turnover will exceed $60,000 in the next 12 months). Either one triggers mandatory registration.
Last verified: 26 July 2026, against current Inland Revenue guidance and the most recent IRD Tax Information Bulletins.
Source data: Goods and Services Tax Act 1985, section 51; central rate file
gst-data.js (REGISTRATION_THRESHOLD).
How the two tests actually work
Section 51 of the Goods and Services Tax Act 1985 sets out two separate ways registration can become compulsory, and you only need to meet one of them.
- The retrospective test: your taxable turnover for the past 12 months, looking back from today, has already exceeded $60,000. This is a backward-looking, purely factual test based on what has actually happened.
- The prospective test: you have reasonable grounds to believe your taxable turnover for the next 12 months will exceed $60,000. This is forward-looking, and it can require registration on day one of a new venture if the expected scale of the work is clearly large enough, even with $0 actually banked yet.
Because the rule is rolling rather than tied to the 31 March tax year, you need to check both tests at any point your circumstances change materially, such as landing a large new contract, not just once a year.
Worked example: Priya's landscaping business
Priya has been running a small landscaping business as a sole trader. Over the past 12 months her actual taxable turnover was $45,000, which sits comfortably under $60,000, so the retrospective test does not require her to register yet. In June, however, she signed two new commercial maintenance contracts that lift her expected turnover for the next 12 months to $65,000.
Because $65,000 is at or above $60,000, the prospective test now applies to Priya even though she has not yet earned that amount. She has reasonable grounds to expect she will exceed the threshold, so she must register for GST now, not wait until her bank statements actually show $60,000 of income.
To sanity-check the new contracts, Priya also looks at her steady monthly turnover, which now averages around $5,500 a month. Annualised, that is $5,500 × 12 = $66,000, which confirms the prospective trigger independently of the contract paperwork. It also shows that, on the retrospective test alone, cumulative turnover at that pace would reach $60,000 in roughly 11 months ($60,000 ÷ $5,500 = 10.9, rounded up), so even without the prospective test she would cross the line before the year was out. Priya registers through myIR, chooses a two-monthly filing frequency, and starts charging 15% GST on her invoices from her registration date.
What counts toward the $60,000
Only taxable turnover counts. That includes standard-rated sales of goods and services, and zero-rated supplies such as exports, where GST is charged at 0% but the sale still counts as taxable activity. It does not include GST-exempt supplies such as residential rent or most financial services, one-off sales of capital assets like a work vehicle, wages or salary from employment, or private, non-business transactions. If you run more than one business as the same sole trader, Inland Revenue combines the turnover from both when testing the threshold, because the test applies to you as the registered person, not to each trading name separately.
Voluntary registration below $60,000
Sitting under the threshold does not mean registration is off the table. Voluntary registration tends to make sense when you have meaningful GST-bearing expenses, such as materials, tools or stock, that you would like to claim back, or when most of your customers are GST-registered businesses who can claim back the GST you charge them, making it close to cost-neutral. It tends to make less sense when most of your customers are private individuals who cannot claim GST back, since registering effectively adds 15% to the price they pay, or when you have very few GST-bearing costs to offset. Weigh the extra compliance, regular returns and GST-specific recordkeeping, against the cashflow and pricing effect before deciding either way.
What happens if you register late
If you exceed $60,000 and do not register, Inland Revenue can backdate your registration to the date you should have registered and assess GST on your taxable supplies from that date, whether or not you actually charged your customers GST at the time. Shortfall penalties, which can range from 20% to 150% of the GST owed depending on your behaviour, and use of money interest on the unpaid amount, can also apply. Voluntarily telling Inland Revenue before they identify the issue themselves generally reduces any penalty significantly, so if this calculator shows you have already crossed the line, acting promptly is worth more than waiting.
Who this calculator is for and what it assumes
This tool is for sole traders, contractors and small business owners who want a quick, honest check against the $60,000 threshold, whether they are already trading or just starting out. It assumes the figures you enter are genuine taxable turnover, not a mix of taxable and exempt income, and that the "steady monthly turnover" projection is a simplification, real turnover rarely arrives in perfectly even monthly amounts. Results are indicative and rounded for display; always confirm your actual registration obligation with Inland Revenue or a registered tax agent before you decide.
Frequently Asked Questions
What is the GST registration threshold in New Zealand?
The threshold is $60,000 of taxable turnover in any rolling 12-month period. Once you exceed it, retrospectively or prospectively, registration is compulsory under section 51 of the Goods and Services Tax Act 1985.
What is the difference between the retrospective and prospective test?
The retrospective test looks backward: if your actual taxable turnover for the past 12 months already exceeds $60,000, you must register. The prospective test looks forward: if you have reasonable grounds to expect your turnover will exceed $60,000 over the next 12 months, you must register now, even before you have actually earned that much.
Does the $60,000 threshold reset every financial year?
No. It is a rolling 12-month test, not tied to the 31 March financial year. You can breach it at any point during the year, and the obligation to register does not disappear if turnover later drops back down.
Should I register for GST voluntarily below $60,000?
It depends on your customers and expenses. Voluntary registration often suits businesses with significant GST-bearing costs to claim back, or with mostly GST-registered business customers. It suits you less if most customers are private individuals who cannot claim GST back, since your prices effectively rise by 15%.
What counts toward the $60,000 taxable turnover figure?
Standard-rated sales and zero-rated supplies such as exports count. Exempt supplies (residential rent, most financial services), one-off capital asset sales, wages, and private transactions do not count.
What happens if I do not register when I should have?
Inland Revenue can backdate your registration and assess GST on all taxable supplies from that date, even though you did not charge customers at the time, plus possible shortfall penalties and use of money interest.
Can I use this calculator if my business has no trading history yet?
Yes. Use the steady monthly turnover field to see your annualised run-rate and how many months it would take to reach $60,000 in cumulative turnover, which helps you plan ahead before you have a full 12 months of figures.
Is the $60,000 figure GST-inclusive or GST-exclusive?
GST-exclusive. The threshold is measured on taxable turnover before any GST is added, because GST is not chargeable until you are registered.
Related NZ GST and Tax Calculators
Calculate.co.nz maintains over 150 calculators, all reviewed and updated in line with current New Zealand legislation. These related tools cover the calculations that typically follow a registration decision:
- GST Calculator: add or remove 15% GST from any amount once you are registered.
- Reverse GST Calculator: extract the GST content from a GST-inclusive total using the IRD 3/23 method.
- Business GST Calculator: net GST payable across multiple sales and expense lines.
- GST for Tradies: practical registration and invoicing guidance for builders, electricians and subcontractors.
- GST Due Dates 2026/27: filing and payment deadlines once you are registered.
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): registering for GST and the $60,000 turnover threshold
- New Zealand Legislation: Goods and Services Tax Act 1985, section 51
- Inland Revenue (IRD): GST overview and how GST works
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