What an Australian Tax Invoice Must Show and When You Must Issue One

The direct answer: who must issue a tax invoice and what it must show

A tax invoice is the document a GST-registered business gives a buyer so the buyer can support a GST credit claim. Under section 29-70 of the A New Tax System (Goods and Services Tax) Act 1999 (the GST Act), the supplier must issue it, it must be in an approved form, and it must carry the supplier's ABN and the price. The Australian Taxation Office (ATO) applies that section through its ruling GSTR 2013/1, which sets out the information requirements in detail.

The fields you need depend on the total you charge including GST. The ATO's list for sales under A$1,000 has seven items. Once the total reaches A$1,000 or more, one more item is added. The table below sets out the full picture.

The timing rule is separate from the fields. If a taxable sale is above A$82.50 including GST and the buyer asks for a tax invoice, the seller must give one within 28 days of the request. Sales of A$82.50 or less do not need a tax invoice even when asked. The 28-day rule also appears in subsection 29-70(2) of the GST Act. The ATO's own guidance on tax invoices confirms the same threshold.

You can use the free calculator on this page to check the GST figure and which fields apply to your sale.

How the A$82.50 and A$1,000 figures are worked out

The two thresholds are both measured against the total price including GST. They are not measured against the price before GST. The A$82.50 figure is simply A$75 plus 10 per cent GST, so it works out to the same number of dollars as the GST-free price of A$75 once GST is added.

1. Add up the total you will charge the buyer, including GST, for the taxable items on the invoice.
2. If the total is A$82.50 or less, no tax invoice is needed on request. You should still keep a record of the sale.
3. If the total is above A$82.50, and the buyer asks for a tax invoice, issue one within 28 days of the request.
4. Work out the GST. GST is one-eleventh of the GST-inclusive price, so divide the total by 11. The GST component is the result, and the price before GST is the total minus that figure.
5. If the total is A$1,000 or more, add the buyer's name or the buyer's ABN to the invoice.

Step 4 is the step most people get wrong. Dividing by 11 gives the GST, not 10 per cent of the total. For a total of A$825, the GST is A$75, and the price before GST is A$750. The division is exact because the GST rate is 10 per cent.

Worked example: a repair job at A$1,650 including GST

Suppose your business is GST-registered and completes a fixed-price repair for a commercial client. The agreed price before GST is A$1,500. GST at 10 per cent is A$150. The total you charge is A$1,650.

Here is how the invoice is checked. The total is above A$82.50, so if the client asks for a tax invoice you must provide one within 28 days. The total is also A$1,000 or more, so the invoice must show the client's business name or ABN in addition to your own identity and ABN. The invoice must show the words that mark it as a tax invoice, the date, the description of the repair with quantity and price, the GST of A$150, and a statement that the total includes GST.

Now change the job to a total of A$660, made up of A$600 before GST and A$60 GST. The buyer's identity is no longer required, because the total is under A$1,000. The other fields still apply, and the buyer can still ask for a tax invoice because the total is above A$82.50.

Cases that change the answer

Several situations change what the invoice must contain or whether it is needed at all.

Sales of A$82.50 or less. These do not need a tax invoice on request. Many businesses still issue a standard invoice or receipt with the same core details because it helps with their own records.

Mixed sales. Some invoices include items that are taxable, GST-free or input-taxed. The ATO treats the last two as non-taxable. The invoice must show clearly which items are taxable, and the GST must be shown only on the taxable items.

The seller is not registered for GST. The GST turnover threshold is A$75,000. Once your GST turnover reaches that level, you must register, and you must register within 21 days of exceeding the threshold, according to business.gov.au. A business below the threshold can register voluntarily. A business that is not registered must not add GST to its prices and must not show GST on its invoices. Its invoices must not carry the words tax invoice. Its invoice should say that no GST is included, and the buyer cannot claim a GST credit on it.

GST groups. If the buyer belongs to a GST group, the invoice must identify the buyer in one of the ways the ATO accepts. These include the buyer itself, the GST group, or the representative member.

Recipient created tax invoices. In some arrangements, the buyer prepares the tax invoice for the supplier. Section 29-70 of the GST Act treats a document of that kind as a tax invoice if it meets the rules. The arrangement generally needs a written agreement and must be in a class the Commissioner has accepted. The ATO explains this in its ruling GSTR 2000/10.

Documents that are read together. Subsection 29-70(1A) of the GST Act allows a buyer to treat an earlier document as a tax invoice if the missing details can be found in another document the seller gave. This is a fallback, not a plan. Your invoice should be complete on its own.

Common mistakes

• Leaving the supplier's ABN off the invoice. The ABN is required by the GST Act and by the ATO's guidance on tax invoices.
• Calling a standard invoice a tax invoice when the business is not registered for GST.
• Showing GST on GST-free items, or leaving out the GST on taxable items.
• Writing vague descriptions such as misc services, which makes the GST hard for the buyer to reconcile.
• Forgetting the buyer's identity or ABN on invoices of A$1,000 or more. Point of sale software often does not capture this unless it is set up to do so.
• Missing the 28-day deadline after a buyer's request. The clock starts from the request, not from the day the buyer receives the invoice.

What to check with your accountant or a lawyer

Some decisions need a professional with your full records. Ask your accountant to confirm your GST turnover over the current and projected twelve-month periods, because the ATO tests both. Ask whether any of your sales are GST-free or input-taxed, and how they should appear on your invoices. If you use a recipient created tax invoice arrangement, or belong to a GST group, have the agreement or group setup reviewed before you rely on it. Ask a lawyer about any dispute over whether a document is a valid tax invoice.

Where AI workers fit

Routine invoice work is a good fit for automation. An AI worker can read each sale from the billing or accounting system, apply the thresholds and field checks described above, and prepare a draft invoice with the required details. It can flag missing buyer identity on sales of A$1,000 or more and stop GST from appearing on invoices for a business that is not registered. A person still approves each invoice, decides on GST treatment, and handles disputes. This explains the rule in general terms; it is not legal or tax advice for your case.