GST and ABN on Invoices: The Australian Rules

An ABN and GST registration are not the same thing. You can have an ABN and still not be registered for GST. If you are not registered, you generally issue an ordinary invoice and do not add GST just because your ABN appears on it. If you are registered for GST and the sale is an ordinary taxable supply, you generally issue a tax invoice that includes the GST information required by the ATO. That is the practical rule most businesses need to apply day to day.

If you want a simple starting format for the non-GST side of that decision, an ABN invoice template can help you lay out seller details, client details, service dates and payment instructions clearly.

ABN and GST registration answer different questions

Your ABN identifies the business or entity supplying the goods or services. GST registration determines whether GST may need to be charged on relevant sales. The ATO and Australian Government guidance treat those as separate issues, not as one automatic package.

That distinction matters because three common shortcuts cause avoidable invoice mistakes:

Mistake	Why it is wrong
“I have an ABN, so I must charge GST.”	An ABN alone does not mean you are GST-registered.
“If I do not charge GST, I should leave off my ABN.”	You may still include your ABN on an ordinary invoice.
“GST-free means the same thing as not GST-registered.”	It does not. GST registration status and the treatment of a particular sale are different questions.

For official background, see the ATO guidance on when GST registration is needed and the ATO tax invoice rules.

When to use an invoice and when to use a tax invoice

If you are not registered for GST, the usual document is an ordinary invoice. It should still clearly identify the seller, the buyer, what was supplied, the dates and the amount due.

If you are registered for GST and the sale is an ordinary taxable supply, the document should generally be a tax invoice. The ATO says a tax invoice needs key information such as seller identity, seller ABN, date, what was sold, the price, the GST payable and wording that makes it clear the document is a tax invoice. For sales of at least A$1,000, buyer identity or ABN is also required.

That gives you a simple document-choice test:

Your position	Usual document
Not GST-registered	Invoice
GST-registered and making an ordinary taxable supply	Tax Invoice

This article is about choosing the correct document and understanding the ABN/GST distinction. If you want a build guide, see How to Create a Tax Invoice in Australia (Step by Step). If you want a final review list before sending, see Australian Tax Invoice Checklist: What to Check Before Sending.

What should appear on the document

The exact format can vary, but the practical basics are consistent. The Australian Government’s invoicing guidance says invoices should clearly identify the seller, buyer, what was sold, when, how much is payable and how to pay.

On either an invoice or a tax invoice, include:

seller name or business name
seller ABN if held; required on a tax invoice
seller contact details
client name and contact details
invoice number
issue date
item or service description
service date or supply period
amount due in Australian dollars
payment terms and payment instructions

For a tax invoice, add the GST information and make it clear the document is a Tax Invoice. If you are not registered for GST, a plain statement such as “GST is not included because the supplier is not registered for GST” helps prevent confusion.

If you want a reusable layout for that ordinary-invoice version, start with an ABN invoice template and adapt the wording to your actual registration status.

Worked example: same service, different document

This fictional example keeps the work the same and changes only the supplier’s GST registration position.

Field	Supplier not registered for GST	Supplier registered for GST and making an ordinary taxable supply
Supplier	Northbank Studio	Northbank Studio
ABN	[your ABN]	[your ABN]
Client	Riverfront Retail Pty Ltd	Riverfront Retail Pty Ltd
Invoice date	9 September 2026	9 September 2026
Service date	1–5 September 2026	1–5 September 2026
Service	Brand review and copy edits, 8 hours	Brand review and copy edits, 8 hours
Rate used for example	A$125.00/hour	A$125.00/hour
Subtotal	A$1,000.00	A$1,000.00
GST	A$0.00	A$100.00
Total due	A$1,000.00	A$1,100.00
Heading on document	Invoice	Tax Invoice

The arithmetic is:

8 hours × A$125.00 = A$1,000.00
If GST applies in this example, 10% of A$1,000.00 = A$100.00
Total due = A$1,100.00

The important point is that the same service and the same ABN field do not decide whether GST appears. GST registration status, and the treatment of the particular sale, decide that.

Two edge cases that cause confusion

1. You have an ABN but are below GST registration level

This distinction is easy to miss. Having an ABN does not by itself mean you should add GST. The registration question depends on the GST rules, including turnover rules and specific exceptions. The ATO guidance explains that the standard registration threshold is A$75,000 for most businesses and A$150,000 for non-profits, with a different rule for taxi and ride-sourcing providers regardless of turnover. It also explains that GST turnover is not the same as profit.

In practice, that means your invoice can still show your business identity, your ABN, the service dates, the amount due and payment details, while making it clear that GST is not included because you are not registered.

2. You are GST-registered, but not every sale is handled the same way

Being GST-registered does not mean every sale should automatically be invoiced in exactly the same GST way. The ATO tax invoice guidance deals with taxable sales, but GST treatment can differ depending on the transaction.

So if a client says, “You have an ABN, just add GST,” that is not a complete instruction. Likewise, if you think you invoiced a sale incorrectly, do not simply replace the old PDF and move on. Check the actual facts and, if needed, confirm the treatment using current official guidance or an accountant.

Practical wording you can adapt

For an ordinary invoice where you are not registered for GST:

Supplier ABN: [your ABN]
Invoice date: [insert date]
Service date or period: [insert date or range]
GST is not included because the supplier is not registered for GST.
Total due: A$[insert amount]

For a tax invoice where you are GST-registered and the sale is an ordinary taxable supply:

Tax Invoice
Supplier ABN: [your ABN]
Invoice date: [insert date]
Service date or period: [insert date or range]
Subtotal: A$[insert amount]
GST: A$[insert amount]
Total due: A$[insert amount]

Those are drafting aids only. Before sending, replace all bracketed fields and make sure the wording matches your real registration status and the actual sale.

A simple check before you send

Before issuing the document, separate the decision into three parts:

Check	Question
Identity	Is the seller name and ABN correct?
Document type	Should this be an invoice or a tax invoice?
GST treatment	Should GST appear on this sale at all?

That approach avoids the most common confusion: assuming the presence of an ABN answers the GST question.

Official sources to rely on

For Australian businesses, the safest starting point is the official guidance:

The core rule is straightforward: an ABN does not automatically create GST obligations on an invoice. First identify whether you are GST-registered for the sale in question. Then choose the correct document: an ordinary invoice if you are not registered, or a tax invoice if you are registered and the sale is an ordinary taxable supply.