Australian tax invoices, done properly

What the ATO expects on an Australian invoice

Australia's requirements are close to New Zealand's but not identical, and the difference that trips people up most is the ABN. If you do not quote your ABN on an invoice, the business paying you is generally required to withhold 47% of the payment and send it to the ATO. That is not a penalty for them — it is the law, and it means a missing eleven-digit number can cost you nearly half your invoice while you wait to claim it back at tax time.

Beyond that, an Australian tax invoice for sales under $1,000 must show that it is a tax invoice, your identity and ABN, the date, what you supplied and in what quantity, the GST amount (or the words "Total price includes GST"), and which items are taxable. Over $1,000 you also need the buyer's identity or ABN. This generator has a field for every one of them.

GST registration is compulsory once turnover reaches $75,000 a year. Under that threshold and not registered? Set the tax mode to No tax — the document heading becomes "Invoice" and no GST line appears, which is exactly right.

What a compliant tax invoice has to contain

An invoice is a request for payment. A tax invoice is also the document your client uses to claim back the GST they paid you — which is why tax authorities are specific about what has to appear on it, and why a missing field can hold up your money while an accounts department sends it back.

In New Zealand the rules were modernised in 2023 and the old requirement to hold a formal "tax invoice" was replaced by taxable supply information. The practical checklist did not really change:

• The words Tax invoice in a prominent place, or a clear indication that the document is one.
• Your registered business name and GST number.
• The date the invoice was issued.
• A description of the goods or services supplied, with quantities where relevant.
• The amount payable and the GST charged — either shown separately, or the GST-inclusive total with a statement that GST is included.
• For supplies over $1,000, the buyer's name and address as well.

If you are not GST registered

Do not charge GST, do not show a GST line, and do not call the document a tax invoice. Set the tax mode to No tax and the heading changes to "Invoice" automatically. Charging GST when you are not registered is a genuine problem, not a technicality — you would be collecting tax you have no right to collect.

Registration becomes compulsory in New Zealand once your turnover passes $60,000 in any twelve-month period, looking both backwards and forwards. Below that it is a choice, and it is not automatically the right one: registering means charging your customers 15% more and filing returns, which is worth it if your clients are businesses claiming it back, and often is not if they are consumers.

Invoice numbering, dates and getting paid faster

Your invoice numbers need to be unique and sequential. That is the whole rule. INV-0001 upwards is perfectly good; adding the year (2026-014) makes end-of-year filing easier; per-client prefixes (ACME-007) help if you invoice a handful of large accounts. What you must never do is reuse a number or leave gaps you cannot explain — both make a GST audit slower than it needs to be.

Payment terms are where most small businesses quietly lose money. Three things move the needle more than chasing:

1. Invoice the day the work finishes, not at the end of the month. Payment clocks start when the invoice arrives, so a week of delay on your side is a week added to your own wait.
2. Put the due date on the invoice as a date, not as "14 days". "Due 12 August 2026" is unambiguous; "payment terms: 14 days" invites a debate about when the clock started.
3. Make paying trivial. Bank account number, and a reference that matches the invoice number, on the invoice itself. Every extra step is another day.

If an invoice goes past due, a short factual email on day one beats a stern one on day thirty. Most late payment is administrative, not hostile — the invoice went to the wrong inbox, or it missed a payment run.