GST and BAS basics for Australian tradies
ONARA Ops · 5 min read · Updated 2 July 2026
GST and BAS sound scarier than they are. For most tradies it comes down to a few simple rules and good records. Get those right and the paperwork mostly looks after itself.
This is a plain overview to help you understand the basics. It is general information, not tax advice, so check with the ATO or a registered tax or BAS agent for your own situation.
Do you need to register for GST?
In Australia you generally must register for GST once your business turnover reaches $75,000 a year, or if you expect it to. Below that it is optional, though some tradies register anyway so they can claim GST back on tools and materials.
Once registered, you charge 10% GST on top of your prices and send that portion to the ATO. You can also claim back the GST you paid on business purchases.
What GST means for your invoices
If you are registered, your invoices need to be valid tax invoices: your ABN, the words 'Tax Invoice', the GST amount, and the total. Customers, especially other businesses, will expect this.
If you are not registered, you must not charge GST or call your document a tax invoice. Our guide on what to put on a tradie invoice covers the details either way.
What is a BAS?
A Business Activity Statement, or BAS, is how you report and pay your GST to the ATO, usually each quarter. It sums up the GST you collected on sales, minus the GST you paid on purchases, and the difference is what you pay or get back.
If you have staff, your BAS may also include PAYG withholding. The key to a painless BAS is simply keeping your income and expenses recorded as you go, rather than in a shoebox at quarter's end.
Keep records as you go
The tradies who dread BAS time are usually the ones catching up on months of paperwork at once. The ones who do not are just recording each invoice and expense as it happens.
Keep your tax invoices, log your expenses, and hold onto receipts. Good, current records turn BAS from a weekend of dread into a quick check.
Make it easier with the right tools
You do not have to do this in spreadsheets. Software that tracks your income and expenses as you invoice can work out your GST and give you the figures for your BAS automatically.
ONARA Books, the optional add-on to ONARA Ops, does exactly that: GST and BAS worked out each quarter, expenses, a mileage logbook and profit per job, alongside your jobs. It is a tool to help you, not a registered tax or BAS agent, so always check the figures or have your accountant review them.
Frequently asked questions
At what income do I have to register for GST?
Generally once your business turnover reaches $75,000 a year, or you expect it to. Below that, registering is optional. Check the current threshold with the ATO.
How often do I lodge a BAS?
Most small businesses lodge quarterly, though some lodge monthly or annually depending on their situation. The ATO tells you your cycle when you register.
Is ONARA Books a replacement for an accountant?
No. ONARA Books helps you keep records and work out your GST and BAS figures, but it is not a registered tax or BAS agent and does not give tax advice. Use it alongside a qualified professional.
GST and BAS, sorted as you go
ONARA Books works out your GST and BAS each quarter from the invoices you are already sending, plus expenses, mileage and profit per job. First month free.
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