The seven things every tax invoice needs
For a taxable sale of less than $1,000, the ATO says a tax invoice must clearly show all of the following:
- That the document is intended to be a tax invoice
- The seller's identity — your business or trading name
- The seller's ABN
- The date the invoice was issued
- A brief description of what was sold, including the quantity where that applies, and the price
- The GST amount payable — either shown separately, or as a statement reading "Total price includes GST" if the GST is exactly one eleventh of the total
- The extent to which each sale is taxable — in practice, which lines carry GST and which do not
Nothing on that list requires special software or a particular layout. A tax invoice can be a Word document, a PDF from an app, or a printed page from a book — what matters is that all seven items are on it.
What changes once the sale hits $1,000
For sales of $1,000 or more, everything above still applies, plus one more field: the buyer's identity or their ABN. So a $600 job can be addressed to "Unit 4 tenant" and still be valid, while a $6,000 job needs the customer's actual business name or ABN on the document.
When you have to issue one
- If a customer asks for a tax invoice, you must give them one within 28 days of the request.
- For sales of $82.50 including GST or less, you are not required to issue a tax invoice at all — though there is no harm in doing so.
- A tax invoice does not have to be paper. Emailing a PDF is fine, provided the document contains everything in the list above.
If you are not registered for GST
You must register for GST once your turnover reaches $75,000 — measured either over the last twelve months or projected over the next twelve — and you have 21 days to do it once you cross the line. Below that threshold, registering is optional.
If you are not registered, you cannot charge GST and cannot issue a tax invoice. You issue a plain invoice instead: same details, but headed "Invoice" rather than "Tax invoice", with no GST line. Charging GST while unregistered is the single most expensive invoicing mistake a new business makes, because the ATO can require you to hand over the GST you collected.
The mistakes that get invoices sent back
| Mistake | What it causes |
|---|---|
| No ABN on the document | Customer can't claim the GST credit, and may be required to withhold 47% of the payment |
| Headed "Invoice" while charging GST | Not a valid tax invoice — customer's bookkeeper will ask you to reissue |
| GST-free items lumped in with taxable ones | The extent of the taxable sale isn't clear, so the GST claim is unsupported |
| Buyer details missing on a $1,000+ invoice | Invalid above the threshold, even though it would have been fine at $900 |
| Duplicate or reused invoice numbers | Reconciliation breaks and BAS figures stop matching your records |
How to make this automatic
Every field above is either a business detail that never changes or a number that comes out of the job. Software should be filling all of it in for you: your ABN and trading name from settings, the customer from the client record, the line items and GST from the quote you already wrote.
That is what JASC does — quotes convert to invoices, GST is applied per line item with a toggle for GST-free work, and the document that lands in your customer's inbox has all seven required fields on it. If you would rather do the arithmetic yourself first, start with how to calculate GST.
Source
Requirements on this page come from the ATO's guidance on tax invoices and registering for GST. This is general information, not tax advice — check with your accountant for your situation.