A complete invoice needs the word Invoice (or the words Tax Invoice if you are registered for GST), your business name and ABN, a unique invoice number, the invoice date, the client details, an itemised list of what you sold, the total due, and clear payment details. Get these elements right and the invoice is easy to read, faster to pay, and ready to stand up if the Australian Taxation Office ever asks questions.
Here is the full checklist to work through every time.
- Heading: Use the word Invoice at the top. If you are registered for GST, the document must instead be headed Tax Invoice, because that exact wording is one of the things the ATO looks for on a valid tax invoice.
- Your business details: Show your business or trading name, your ABN, and a contact method such as an email, phone number, or address. The ABN matters because if you do not quote one, some customers may be required to withhold tax from your payment.
- Unique invoice number: Give every invoice its own sequential number, for example 0001, 0002, and so on. This keeps your records clean and lets you and your client refer to a single document without confusion.
- Invoice date and due date: State the date you issued the invoice and a clear due date. A due date written as a calendar date, such as due 15 July 2026, removes any argument about when payment is expected.
- Client details: Add the client name and, for larger jobs, their business name or address. Under ATO rules, once a tax invoice is for a sale of 1,000 dollars or more, it must also show the buyer identity or their ABN, so it is sensible to capture this whenever the total is significant.
- Itemised description: List each product or service on its own line with a description, the quantity, the rate or unit price, and the line amount. Itemising builds trust and reduces back and forth queries.
- Subtotal, GST, and total: Show the subtotal before tax. If you are registered for GST, show the GST as a separate line (or state that the total includes GST), then show the final total amount due in one obvious place.
- Payment terms and payment details: Spell out the terms, for example payment within 14 days, and include exactly how to pay, such as a BSB and account number or a PayID.
A quick note on the GST point. You only need to head a document Tax Invoice and charge GST if your business is registered for GST. If you are not registered, you simply issue a regular invoice with no GST line. Either way, InvoiceSonic is a free invoice generator that lays these fields out for you in the right order, so you can produce a tidy, compliant looking invoice without building a template from scratch. This is general information only and is not tax advice, so check your own circumstances with a registered tax agent or the ATO if you are unsure.