You must register for GST if your business or enterprise has a GST turnover of A$75,000 or more — the GST threshold — or A$150,000 or more per year if you run a non-profit organisation. Once you're required to register, you have 21 days to do it. Taxi and limousine travel for passengers, including ride-sourcing, must register regardless of turnover (ATO, Registering for GST, last updated 14 September 2026; checked 1 October 2026).
Before any of that, you need an Australian business number (ABN). Registering is not a separate decision you make after GST — it's the prerequisite.
What counts as GST turnover?
The ATO defines GST turnover as gross income from all businesses minus GST. The threshold isn't a calendar-year figure. It's measured either:
- looking back — the current month plus the previous 11 months; or
- looking forward — the current month plus the next 11 months, when you're projecting turnover.
That second measure is why a brand-new business can be caught immediately. If you're starting up and you project a GST turnover at or above the threshold in your first year of operation, you're required to register (ATO, Registering for GST, last updated 14 September 2026).
| Who | Threshold | Source and date |
|---|---|---|
| Business or enterprise | A$75,000 or more GST turnover | ATO, Registering for GST, updated 14 Sep 2026 |
| Non-profit organisation | A$150,000 or more per year | ATO, Registering for GST, updated 14 Sep 2026 |
| Taxi or limousine travel for passengers (incl. ride-sourcing) | No threshold — register regardless of turnover | ATO, Registering for GST, updated 14 Sep 2026 |
Why do taxi and ride-sourcing drivers have to register anyway?
Because the ATO applies a separate rule to them. If you provide taxi or limousine travel for passengers — ride-sourcing is explicitly included — you must register for GST regardless of your GST turnover. It applies to owner-drivers and to drivers who lease or rent a taxi. There is no A$75,000 entry point to wait for; the obligation attaches to the activity.
What is the 21-day rule, and when does it start?
The 21 days run from the point at which you become required to register — not from whenever you get around to it. In practice, that means the clock is tied to your turnover position: the moment your GST turnover reaches the threshold, or you project that it will, or you start providing taxi or ride-sourcing travel.
What do I need before I register?
An ABN. The ATO states plainly that before you register, you need to have an Australian business number. Applying for one through the Australian Business Register is free (business.gov.au, Register for an Australian Business Number; checked 1 October 2026).
You're entitled to an ABN if you're carrying on or starting an enterprise in Australia, making supplies connected with Australia's indirect tax zone, or you're a Corporations Act company (Australian Business Register, ABN entitlement, last modified 29 February 2024; checked 1 October 2026).
One boundary matters here: you're not entitled to an ABN for work you carry out as an employee, including as an apprentice, trade assistant or labourer, even if the arrangement is called contracting. An employer shouldn't ask you to get an ABN as a condition of employment.
What happens if I register without being entitled?
The ABR warns that you may face prosecution or criminal charges if you apply for an ABN, register for GST and claim GST refunds when you're not entitled. It also notes that it can review ABN entitlement at any time (Australian Business Register, ABN entitlement, last modified 29 February 2024).
That risk is what makes the employee-versus-contractor distinction worth settling before you register, rather than after.
How do I register?
The ATO's registration page is the starting point, and the sequence is short:
- Confirm you're entitled to an ABN and apply for one if you don't have it — free through the ABR.
- Work out your GST turnover using the 11-month look-back or look-forward test.
- Check whether the taxi or ride-sourcing rule applies to you, which overrides the threshold.
- Register within 21 days of becoming required to register.
FAQ
Do I need to register if my turnover is well under A$75,000?
Not on the strength of turnover alone. The ATO requires registration at A$75,000 or more of GST turnover — unless you provide taxi or limousine travel for passengers, including ride-sourcing, in which case turnover is irrelevant (ATO, Registering for GST, updated 14 September 2026).
Is the threshold different for a non-profit?
Yes. A non-profit organisation registers when its GST turnover is A$150,000 per year or more (ATO, Registering for GST, updated 14 September 2026).
How is turnover counted for a business that's just starting?
Using the current month plus the next 11 months. If that projection puts you at or above the threshold in your first year, you register.
Can I register for GST without an ABN?
No. The ATO requires you to have an ABN before you register.
What if I lease the taxi rather than own it?
You still must register. The ATO's rule applies to owner-drivers and to drivers who lease or rent a taxi.