GST Number NZ: What It Is, the Format and How to Check One

Short answer: In New Zealand your GST number is your IRD number: once you register for GST, the same 8 or 9 digits become your GST number, usually written like 123-456-789. You must show it on taxable supply information for sales over $200. To check whether a business is GST registered, look for its GST number on its invoice, search the NZBN register (which shows a GST number only if the business chose to add it), and contact Inland Revenue if something does not add up.

The rules here are Inland Revenue’s, from its register for GST and taxable supply information pages, and apply in the 2027 tax year (1 April 2026 – 31 March 2027). If you still need to register, GST registration in NZ covers the $60,000 threshold and the myIR steps, and GST in NZ explains how the tax itself works.

What is a GST number in NZ?

A GST number is the number Inland Revenue uses to identify you as registered for GST, and in New Zealand it is your IRD number. It tells customers and suppliers that you charge GST and file GST returns.

You get it by registering for GST. Inland Revenue’s register for GST page says your GST number will be the same as your IRD number, and in most cases you get immediate confirmation of your GST number and registration details when you register in myIR. There is no separate number to apply for.

Registration is compulsory once your turnover was at least $60,000 in the last 12 months, or you expect it to be at least $60,000 in the next 12, and you then have 21 days to register, under Inland Revenue’s registering for GST rules. Below that, it is voluntary.

Is a GST number the same as an IRD number?

Yes, for whoever is registered. Which IRD number becomes the GST number depends on who is in business:

Who is registered	Their GST number
Sole trader	Your personal IRD number: you do not get a second number for the business
Company	The company’s own IRD number, often issued with its GST number at incorporation
Partnership or trust	The partnership’s or trust’s own IRD number

The difference is status, not digits. Most people who earn income here have an IRD number; only people and organisations registered for GST can call that number a GST number and charge GST. If you are not registered, do not put your IRD number on an invoice as a GST number. What is a sole trader explains why a sole trader and the business share one number.

What does a NZ GST number look like?

A New Zealand GST number has 8 or 9 digits, because it is an IRD number. Inland Revenue’s help page on problems with IRD numbers explains that IRD numbers can contain 8 or 9 digits: a 9-digit range was added in June 2008, and older numbers have 8.

Format	Example	Notes
9 digits	123-456-789	The current range; usually written in three groups of three
8 digits	12-345-678	Older numbers; still valid
8 digits entered into a system	012-345-678	Inland Revenue says to add a leading zero when entering an 8-digit number

The hyphens are only for readability; 123456789 and 123-456-789 are the same number. A number with fewer than 8 or more than 9 digits is not a valid IRD number, and a quick count of digits is the first check worth doing on a supplier’s invoice.

The examples above are made up. Do not copy a “sample” GST number onto a real invoice.

Where must my GST number appear?

On every record that carries GST details for a sale over $200, and on corrections to them. Inland Revenue’s taxable supply information rules set the tiers:

Document	Must it show your GST number?
Sale of $200 or less (incl. GST)	No taxable supply information has to be provided to the buyer, though many businesses show the number anyway
Sale over $200	Yes: name or trading name, GST number, date, description and the GST
Sale over $1,000	Yes, plus the buyer’s name and one identifier if the buyer is GST registered
Credit note (supply correction information)	Yes: your name and GST number, the date, the original invoice it corrects, and the correction
Quotes and pro formas	Not required, but showing it tells the customer GST will be added

For sales over $200, you must provide the information to a GST-registered buyer within 28 days of a request. The simplest way to stay compliant is to print your GST number on your invoice template once, near your name, as the NZ invoice template does.

How do I check if a business is GST registered in NZ?

Start with the documents they give you, then use the public NZBN register, and contact Inland Revenue if you still have doubts.

1. Look at the invoice. A GST-registered seller must show its GST number on taxable supply information for any sale over $200. If you are being charged GST on a sale over $200 and there is no GST number, ask for one. A GST-registered buyer can request the information, and the seller must provide it within 28 days.
2. Check the format. Count the digits: 8 or 9. Anything else is wrong.
3. Search the NZBN register. The New Zealand Business Number register, searchable at nzbn.govt.nz, covers companies and also sole traders, partnerships and trusts that have an NZBN. The Companies Office’s NZBN page explains that businesses can add optional public details, and a GST number is one of them. If it is listed, compare it with the invoice; if it is not, that proves nothing, because adding it is voluntary.
4. For companies, start from the Companies Register. You can search the Companies Register by company name, number or NZBN, then use the NZBN to look the company up on the NZBN register.
5. Ask Inland Revenue. If a number looks wrong or a supplier will not provide one, contact Inland Revenue before you claim the GST.

In practice the NZBN register is the closest thing to a public GST number search, and it only works when the business has chosen to list its number. For most day-to-day purchases, the GST number on a proper invoice is the evidence you rely on.

What if a supplier charges GST but has no GST number?

Do not claim that GST until it is sorted out. A business that is not registered must not charge GST: Inland Revenue’s rules say that adding GST to your prices means you must register, whatever your turnover. Ask the supplier for their GST number and a corrected invoice. If they are not registered, ask for an invoice without GST and pay the GST-free price.

On your own side, the same rule applies. Until your registration is confirmed, invoice without GST and without a GST number, and if you quoted before registering for work you will invoice afterwards, agree in writing whether GST is added. How to invoice as a contractor in NZ covers the switch-over.

GST number, IRD number, NZBN and company number: what is the difference?

Four numbers get mixed up, and only one of them belongs in the GST field on an invoice.

Number	Who issues it	What it is for	On your invoice?
IRD number	Inland Revenue	Your tax identity, for income tax and everything else	Only as your GST number, if you are registered
GST number	Inland Revenue, on GST registration	Shows you are GST registered; same digits as your IRD number	Yes, for sales over $200
NZBN	The Companies Office, which runs the NZBN register	A business identifier others can look up	Optional
Company number	Companies Office	Identifies an incorporated company	Optional

Keeping GST details right on every invoice, and where does Keel fit?

Once your GST number is on your invoice template, the remaining work is keeping each invoice, credit note and receipt where you can find it for your GST return and for the 7 years Inland Revenue’s record keeping rules require.

Keel: Invoice Maker & Receipts, an iPhone app by Ilura Technology OÜ, keeps those records together on your phone. You create estimates that become invoices in one tap, send PDF invoices, capture receipts and expenses, and keep each item under its job and customer. “Who owes you” shows unpaid invoices and prepares reminder drafts that you review and send yourself; nothing is sent automatically. Records stay on your iPhone, with no account, no bank connection and no cloud sync, and the App Store privacy label reads “Data Not Collected”.

Keel is a record keeper, not a compliance tool: it does not register you for GST, check other businesses’ GST numbers, file GST returns or connect to Inland Revenue, so check that your GST number appears on every invoice over $200. It is free with no invoice limit (free invoices carry a small “Made with Keel” footer), and Keel Lifetime is a one-time purchase of $249.99 USD (the App Store shows your local price) that adds custom branding, signature, premium templates and accountant-ready exports and reports. Keel on the App Store. More guides are on the New Zealand hub.

Frequently asked questions

What is a GST number in NZ? It is your IRD number, once you are registered for GST. Inland Revenue does not issue a separate number: the same 8 or 9 digits identify you for income tax and, after registration, for GST. You show it on invoices for sales over $200.

How do I find my GST number? If you are registered, it is your IRD number, shown in myIR and on your GST registration confirmation. A sole trader’s GST number is their personal IRD number; a company’s is the company’s IRD number. If you are not registered for GST, you do not have a GST number.

How can I check if a company is GST registered in NZ? Check that its invoice shows a GST number with 8 or 9 digits, then search the NZBN register, where businesses can choose to list their GST number. You can find a company’s NZBN on the Companies Register. If the number is missing or does not match, contact Inland Revenue before claiming the GST.

What format is a NZ GST number? Eight or nine digits, usually written in groups such as 123-456-789. Nine-digit numbers have been issued since June 2008; older numbers have eight. When entering an 8-digit number into a system, Inland Revenue says to add a leading zero.

Do I need a GST number on my invoice? Only if you are GST registered and the sale is over $200. At $200 or less no taxable supply information has to be provided to the buyer, although showing your number does no harm. If you are not registered, leave it off and do not charge GST.

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This article is general information, not tax advice. Consult a qualified New Zealand tax professional.