If you run a small business in Australia, GST and your Business Activity Statement (BAS) will come up sooner or later. Here is how they work, without the jargon.
Do I need to register for GST?
You must register for GST once your GST turnover reaches $75,000 a year (or you expect it to). Many businesses register earlier, because it lets them claim back the GST included in their business purchases.
What is a BAS?
It is the form you use to report and pay GST, and sometimes PAYG instalments and PAYG withholding. Most small businesses lodge quarterly.
Quarterly BAS due dates for 2026–27
July to September: 28 October 2026
October to December: 28 February 2027
January to March: 28 April 2027
April to June: 28 July 2027
Lodging through a registered tax or BAS agent may give you extra time.
Common mistakes
Claiming GST without a valid tax invoice
Mixing personal and business spending
Leaving bookkeeping until the due date
Missing the deadline because there was no cash set aside for it
Keep your books up to date monthly and set aside the GST you collect, so the BAS is a routine task and not a scramble.
If you are unsure whether you should be registered, or you are behind on lodgements, speak to a registered tax agent early. It is usually easier to fix than to ignore.
General information only. It does not consider your circumstances.