An invoice that isn’t a valid tax invoice is your customer’s problem before it’s yours — and that’s exactly why it becomes yours. Their bookkeeper can’t claim the GST credit on a purchase over $82.50 without one, so a document that’s missing a field doesn’t get queried, it gets parked. You find out three weeks later, when you ring about the money.
The requirements are short, they haven’t changed in years, and most invoices that fail do it on the same two or three lines.
The seven things every tax invoice needs
For a taxable sale under $1,000, the ATO asks that a buyer can clearly work out seven things from the document:
- That it’s a tax invoice. The words have to be on it. An invoice headed “Invoice” is not a tax invoice, however much GST is on it.
- Who sold it — your business name, as your customer knows you.
- Your ABN.
- The date you issued it.
- What you sold — a description of the items, with the quantity and the price.
- The GST payable, either as an amount or as a statement that the total price includes GST.
- Which lines are taxable. Obvious when everything is. Not obvious the moment one line isn’t.
In practice that’s a header block and a table of lines:
TAX INVOICE
Kembla Electrical Pty Ltd
ABN 12 345 678 901
Invoice 1042 · Issued 14 July 2026
Four lines, and three of the seven are already done.
What changes once a sale reaches $1,000
One more field: the buyer’s identity or their ABN. Their trading name is enough — you don’t need to chase an ABN for a homeowner — but the invoice has to say who it was for, not just where the work happened.
The cheapest way to get this wrong is a job that grows. A $900 quote plus two variations is a $1,400 invoice, and the template that was fine in the morning isn’t by knock-off.
“Total price includes GST” is a shortcut with a condition
If every line on the invoice is taxable, GST is exactly one-eleventh of the total, and the statement “Total price includes GST” satisfies requirement six on its own. You don’t have to print the dollar figure.
The condition is the whole sentence. The moment one line isn’t taxable, the shortcut stops working: you have to show the GST amount, and show which lines it applies to. Since that’s a decision you’d have to make correctly every time, showing the GST amount on every invoice is the version that can’t catch you out. It also saves your customer’s bookkeeper a subtraction, which is not nothing when they’re deciding whose invoice to process first.
Two numbers worth committing to memory
$82.50. Under that, including GST, your customer doesn’t need a tax invoice to claim the credit — a receipt will do. Over it, they do. Most of what you send is over it.
28 days. If a customer asks you for a tax invoice, you have to give them one within 28 days of the request. That one is a legal obligation, not a courtesy, and it’s a good reason to be able to reissue an invoice without rebuilding it.
The parts the ATO doesn’t ask for, and your cash flow does
Compliance gets the invoice accepted. These get it paid:
- A due date, in words. “Net 14” means nothing to half the people who read it. “Due 28 July 2026” means one thing.
- How to pay, on the invoice itself. BSB and account number, on the document they’re looking at, not in the email it arrived with.
- Their reference. The purchase order number, the work order, the site address they know the job by. An invoice their system can’t match goes to the bottom of the pile no matter how correct it is.
- Variations itemised separately from the quoted work. Bundled into one line, a variation reads as a price rise. Listed with what was approved and when, it reads as a record — and nobody argues with a record.
The version that’s right every time
None of this is hard. It’s just seven things, on every invoice, every time, usually at the end of a long day — and that’s the part people lose.
Worksted builds the invoice from the job rather than from a blank template. The words Tax invoice, your ABN, GST broken out on its own line, and your BSB and account number are on it because that’s how invoices are made here, not because somebody remembered. The lines come from work that already happened: the hours your crew logged on site, the supplier receipts they photographed at the counter, the variations someone approved before they were done. Nothing is typed twice, which is also why nothing is typed wrong.
See how invoicing works, or put one of your own jobs through it and see what comes out the other end.