How to Create a Valid GST Invoice in New Zealand (2025 Guide)

Creating a valid GST invoice is crucial for any New Zealand business registered for GST. The Inland Revenue Department (IRD) has specific requirements that must be met to claim GST deductions. This guide covers the requirements, a worked GST example, a compliance checklist, and record-keeping basics.

What is a GST Invoice?

A GST invoice — formally called a document providing "taxable supply information" under current IRD rules — is the record that shows the GST component of a transaction. In New Zealand, GST is set at 15%.

Many businesses still use the term "tax invoice" on their documents, and that is fine — the label is optional as long as the required information is present. What matters is the content, not the heading. If you are GST-registered, you must provide taxable supply information when a customer requests it so they can claim the GST paid as an input tax credit.

When Do You Need to Register for GST?

You must register for GST if your business turnover is, or is expected to be, more than NZ$60,000 in any 12-month period. This is a rolling 12-month window — not just a financial year — so watch your cumulative revenue as you approach the threshold. You have 21 days from the date you exceed it to apply for registration through myIR.

You can also voluntarily register if your turnover is below this threshold — useful if you have significant GST-bearing expenses you want to claim back as input tax credits.

If you are not yet GST-registered: do not add GST to your invoices or display a GST number. Charging GST without being registered is not permitted. For more on when registration applies, see the NZ sole trader tax guide.

NZ GST Invoice Requirements: A Compliance Checklist

IRD updated invoicing rules in 2023. The required details depend on the value of the supply. Check the IRD taxable supply information page for current thresholds.

For most business-to-business invoices, a compliant NZ GST invoice should include:

• Your business or trading name
• Your GST registration number (the same as your IRD number — 8 or 9 digits)
• The date the invoice is issued
• The buyer's name (or trading name) — required above certain thresholds
• A description of the goods or services supplied
• The quantity or volume of goods or services (for higher-value supplies)
• The total amount payable
• The GST content shown separately, or a statement that GST is included and the GST rate (e.g. "GST included at 15%")

For the full detail on which fields are required at each invoice value tier, use the NZ tax invoice requirements guide.

Worked GST Calculation Example

Here is how the numbers look on a real invoice. A plumber completing a residential job itemises their work as follows (or use the GST calculator to check the maths instantly):

Subtotal (excl. GST): $715.00

GST at 15%: $715.00 × 0.15 = $107.25

Total payable (incl. GST): $715.00 + $107.25 = $822.25

The invoice shows each line excluding GST, the subtotal excluding GST, the GST amount separately ($107.25), and the total the client actually pays ($822.25). Both the GST-exclusive and GST-inclusive totals are visible so the client can clearly see what the GST component is.

Quick GST formulas to remember:

• To add 15% GST to an exclusive price: multiply by 1.15 (e.g. $715 × 1.15 = $822.25)
• To find the GST in a GST-inclusive total: divide the total by 1.15, then subtract from the original (e.g. $822.25 ÷ 1.15 = $715.00; $822.25 − $715.00 = $107.25 GST)
• To find just the GST component of a GST-inclusive total: multiply by 3 then divide by 23 (e.g. $822.25 × 3 ÷ 23 = $107.25)

Common GST Invoice Mistakes to Avoid

• Missing GST number: Include it on every invoice if you are registered. Without it, your client cannot claim the GST as an input tax credit.
• Wrong date: Use the invoice issue date. The date is required on a compliant invoice.
• Unclear GST treatment: Show GST separately or clearly state that GST is included and at what rate. "Total $822.25 incl. GST" without showing the GST amount separately may be acceptable for lower-value invoices — but showing it separately is clearer for everyone.
• Incorrect GST calculation: Double-check the 15% math. The most common errors are rounding mistakes on multi-line invoices — calculate at line level and then sum, rather than trying to estimate.
• Missing buyer details on higher-value invoices: Add the customer name when required.
• Charging GST when not registered: You cannot charge or collect GST if you are not registered. This is an offence.

Record-Keeping for GST Invoices

Good record-keeping protects you if IRD ever queries your GST returns and makes filing faster. The rules:

• Keep all invoices for at least 7 years — both the ones you issue (your sales) and the ones you receive (your purchases and expenses)
• Electronic copies are accepted by IRD — a digital folder system or cloud storage is fine
• Records must be in English or in a form that can be readily converted (e.g. scans of paper receipts)
• If you claim GST on expenses, you must hold the supplier's invoice or receipt showing their GST number and the GST amount

Invoicing software keeps your issued invoices organised automatically and produces the GST workings you need for each GST return period. Invio calculates 15% GST on every line and generates returns-ready totals. See how Invio handles GST.

Free GST Invoice Template Download

We've created a free, IRD-compliant GST invoice template that you can download and use today:

Download Free NZ GST Invoice Template (HTML)

The file opens in your browser so you can edit the yellow fields, then click Download or Print/PDF to keep your customised copy. For the full list of required fields, see the NZ tax invoice requirements guide. If you prefer a ready-to-use layout with your branding, open the NZ invoice template instead. For a step-by-step walkthrough of the whole invoicing workflow, the how to invoice as a sole trader guide covers everything from setup to sending.

Automate Your GST Invoicing with Invio

Tired of manually calculating GST and chasing payments? Invio automates everything:

• Automatic GST calculations at 15%
• GST invoices aligned with current IRD requirements
• Recurring invoices for subscription services
• Automated payment reminders
• NZD by default, built for Kiwi businesses

Start using Invio today — or compare plans. The free Starter plan covers up to 5 invoices per month.

Frequently Asked Questions

Can I use a quote as taxable supply information?

No. A quote is not taxable supply information. Issue an invoice with the required details once the goods or services have been supplied.

How long must I keep GST invoices?

You must keep records for at least 7 years. This includes both invoices you issue and those you receive.

What if a customer asks for an invoice but I'm not GST registered?

You can issue a regular invoice, but it should NOT include a GST number or state that GST is included (because you're not charging GST).

Do I need a GST number on every invoice?

Yes, if you're GST registered. Your 8 or 9-digit IRD number is your GST number.

What is the GST rate in New Zealand?

New Zealand GST is 15%. This rate has been in place since 1 October 2010.