Do I need to register for GST?
The $75,000 turnover test, who must register regardless, and what changes once you're registered.
Last updated 3 November 2026
If you’re running a business or side hustle, there’s one number that decides whether GST applies to you: $75,000. Here’s when you have to register, when you don’t, and what changes once you do.
The $75,000 turnover test
You must register for GST if any of these apply:
- Your GST turnover is $75,000 or more (current or projected).
- You’re a non-profit organisation with turnover of $150,000 or more.
- You provide taxi or ride-share travel — you must register regardless of turnover, even from the first dollar.
- You want to claim fuel tax credits.
Below $75,000 and not in those categories, registering is optional.
What “turnover” actually means
GST turnover is your gross business income (excluding any GST), not your profit. The ATO tests it two ways:
- Current turnover: this month plus the previous 11 months.
- Projected turnover: this month plus the next 11 months.
If either reaches $75,000, you need to register — so a fast-growing business may need to register based on where it’s heading, not just where it’s been. You have 21 days to register once you’re required to.
What changes once you’re registered
- You add 10% GST to most of your sales.
- You can claim GST credits on the GST in your business purchases.
- You lodge a business activity statement (BAS) and pay the net GST to the ATO.
- You must issue tax invoices for sales over $82.50 (including GST).
Should you register voluntarily?
If you’re under $75,000, registering early lets you claim GST credits on purchases — handy if you have big start-up or equipment costs. The downside is adding 10% to your prices (which can matter if your customers are everyday consumers) and the ongoing BAS admin. For a small side business under the threshold, staying unregistered is often simpler.
Work out the GST
Once you’re registered, our GST calculator adds or removes the 10% GST on any amount, so you can price correctly and check what GST is inside a total.
Thresholds and rules are set by the ATO and can change — confirm the current position on ato.gov.au or with a registered tax agent before registering.
Work out your own numbers
Frequently asked questions
When do I have to register for GST?
You must register once your GST turnover reaches $75,000 or more ($150,000 for non-profit organisations), or if you expect it to. You also must register if you drive taxi or ride-share, regardless of turnover. Below the threshold, registration is optional.
How is GST turnover measured?
By your gross business income (excluding GST), not profit. The ATO looks at both 'current' turnover — this month plus the previous 11 — and 'projected' turnover — this month plus the next 11. If either reaches $75,000, you need to register.
What happens once I'm registered for GST?
You add 10% GST to most sales, can claim GST credits on business purchases, and lodge business activity statements (BAS) to report and pay the net GST. You also need tax invoices for sales over $82.50 including GST.
Should I register for GST voluntarily?
You can register below $75,000 if you want to claim GST credits on purchases — useful if you have significant business expenses. The trade-off is adding 10% to your prices and the admin of lodging BAS. For many small side businesses under the threshold, staying unregistered is simpler.