GST on invoices · Australia

Just registered for GST? What changes on your invoices

By Alex Lunnon · Updated 26 September 2026 · Checked against ATO guidance, September 2026

Day one: your registration date

When you register you nominate the date it takes effect, and everything hinges on it. Sales before that date have no GST; sales from it do. If you crossed $75,000 and registered within 21 days, the date is the day you were required to register. If you registered late, the ATO can set the date back to when you should have registered, and you'll owe GST on the sales since then even though you never charged it.

Your invoices

From the registration date, every invoice for a taxable sale is a tax invoice:

  • the heading Tax Invoice;
  • your name and ABN;
  • the date and an invoice number;
  • what you sold, with quantity and price;
  • the GST amount, or GST-inclusive prices with the words "Total price includes GST";
  • for sales of $1,000 or more, the buyer's name or ABN.

Open quotes need re-issuing. To a business, add "plus GST" and the GST amount. To a household, show the GST-inclusive total as the prominent figure. A job that started before the date and finishes after it is one to ask your accountant about; the general rule is that the date of the sale decides.

Your prices

Business clients claim the GST back, so adding 10% costs them nothing and they expect it. Households pay the extra 10% in full, so this is a real pricing decision: add it, absorb it (one-eleventh of the old price is now GST), or something in between. Whatever you decide, price lists, booking pages and your website must show consumers a total that includes GST.

Your BAS

Registration puts you on a Business Activity Statement cycle, quarterly for almost every small business. On it you report your total sales, the GST you collected, and the GST you paid on business purchases; you pay the difference, or receive a refund if you bought more than you sold. The standard due dates are 28 October, 28 February, 28 April and 28 July; a registered agent gets longer.

You also choose an accounting basis. Cash means GST is reported when money changes hands, which suits most small businesses because you never pay GST on an invoice that hasn't been paid.

Your GST credits

From the registration date you can claim the GST in what you buy for the business: equipment, software, materials, a share of your phone and car. Two conditions: it's for the business, and you hold a tax invoice for anything over $82.50. Keep them. Purchases before the date don't qualify; if there's a big one, the backdating question above is the one to raise with your accountant.

Worked example

Mara's registration takes effect on 1 October. Two identical $2,000 logo jobs:

Invoiced 28 September Invoiced 3 October
Heading Invoice Tax Invoice
Logo design $2,000.00 $2,000.00
GST — $200.00
Total $2,000.00 $2,200.00

Her first BAS covers October to December. She invoiced $24,000 plus $2,400 GST, and bought a $1,980 laptop that included $180 GST. She reports $2,400 collected, $180 paid, and pays the ATO $2,220.

Tell people

Your business clients first: they'll want tax invoices from now on and won't mind the 10%. Your accountant, who will set up the BAS lodgement. And every place your prices appear: the website, the booking page, the price list on the wall. The one thing that doesn't change is your ABN; the registration attaches to it.

Common questions

Do I add GST to invoices I sent before registering but haven't been paid for yet?

No. GST attaches to sales made from your registration date. An invoice issued before that date is a pre-registration sale, whenever it's paid.

Can I claim the GST on the laptop I bought last month?

Not through your BAS: credits start from your registration date too. The ATO can backdate a registration, up to four years, but then GST applies to your sales from that date as well. Talk to your accountant before asking for that.

Do my prices have to go up by 10%?

For business clients, add it: they claim it back, so it costs them nothing. For households it's a real price rise, so decide whether to add it, absorb it, or split the difference. Whatever you decide, the price you show a consumer must include the GST.

What's the first BAS like?

Quarterly by default, due 28 days after the quarter ends (later if an agent lodges it). You report total sales, GST on sales and GST on purchases; the ATO pre-fills the form and sends the due date. Keep a tax invoice for every purchase over $82.50, or the credit isn't claimable.

Does my ABN change?

No. GST registration attaches to your existing ABN. ABN Lookup will show "Registered for GST from" and the date.

Sources

  1. ATO — Registering for GST
  2. ATO — Tax invoices
  3. ATO — When you can claim a GST credit
  4. business.gov.au — How to invoice

General information from the maker of an invoicing app, not tax or legal advice. Rules change and your situation may differ; check the sources above or ask your accountant before relying on this page.