In everyday commercial practice, the words invoice and tax invoice are often used interchangeably. They are not the same thing. The distinction is created by the A New Tax System (Goods and Services Tax) Act 1999 (Cth) and has practical consequences for both the issuer and the recipient — and for what happens when a debt is disputed or referred for recovery.
What makes an invoice a tax invoice
Under the GST Act, a tax invoice must contain specific information: it must be issued by the supplier, identify the supplier's ABN, state that it is a tax invoice (either with those words or by clear implication), describe the supply, show the consideration and the GST amount (or indicate that the stated price includes GST). For supplies over $1,000, the recipient's identity must also appear.
An invoice that does not contain all of these elements is a plain invoice — it creates an obligation to pay, but it does not allow the recipient to claim an input tax credit (ITC) on the GST component. For a GST-registered business, this matters: they need a valid tax invoice to claim the credit.
When you must issue a tax invoice
If your business is registered for GST and the supply is taxable, you are required to issue a tax invoice on request. A recipient who is GST-registered and requests a tax invoice must receive one within 28 days. Failing to provide one is technically a breach of the GST Act, though the ATO rarely pursues individual failures of this kind.
The ABN requirement
Every tax invoice must show the supplier's ABN. An invoice without an ABN is not a valid tax invoice. It is also relevant to withholding obligations: under the Tax Administration Act 1953 (Cth), if a payer receives a supply from an entity that does not quote its ABN, the payer may be required to withhold 47% of the payment. In practice, many businesses overlook this obligation for small supplies, but it is technically on the record.
Why it matters in a recovery
In debt recovery, documentation quality directly affects outcomes. An invoice that is missing ABN, GST disclosure, or the words tax invoice will still evidence the debt — but a debtor with a competent accountant may dispute the amount on the basis that the GST component was not properly disclosed, or argue that the obligation to pay is unclear. A valid, correctly formatted tax invoice removes that avenue.
It also affects any GST adjustment claim you make. If you write off the debt as bad, you can claim back the GST remitted on the unpaid supply — but you need to demonstrate that a valid tax invoice was issued and that the GST was included in a return that has been lodged.
Practical checklist for every invoice
- Your business name and ABN
- The words "Tax Invoice"
- Date of issue
- Description of the goods or services supplied
- Total price and GST amount (or "includes GST")
- For supplies over $1,000: recipient's name or ABN
If your standard invoice template is missing any of these, fix it before the next invoice goes out — not when a debt is already in dispute. Speak to Merion if you have a recovery where the documentation is in question.