Guide · Updated 17 August 2026
GST registration: when you must, and when you shouldn't
The thresholds, the exceptions that catch people out, and how to decide whether to register voluntarily.
When do you have to register for GST?
When your GST turnover reaches $75,000 in a 12-month period — either the past 12 months, or where you expect to reach it in the next 12. Non-profit bodies have a $150,000 threshold. Two exceptions matter: taxi travel and ride-sourcing (Uber and similar) require registration from the first dollar regardless of turnover, and businesses wanting fuel tax credits must be registered. You must register within 21 days of becoming required to, and registration is backdated to the date the requirement arose — not the date you noticed.
- $75,000 threshold ($150,000 non-profits)
- Ride-sourcing: register from the first dollar
- Register within 21 days of the requirement
- Cash or accrual basis available under $10m turnover
How turnover is measured
GST turnover is your gross business income excluding GST, input-taxed sales and sales not connected with Australia. It's tested on a rolling 12-month basis, both backwards and forwards — so a single large project that will push you over means you register now, not at the end of the year.
The consequence of late registration is uncomfortable: registration is backdated, so you owe GST on sales already made at prices that didn't include it. Effectively you fund one-eleventh of that revenue yourself.
Should you register voluntarily?
Yes, usually, if your customers are businesses. They claim the GST back, so your prices are effectively unchanged, and you claim credits on tools, equipment, stock and vehicle costs. For a new trade business buying a ute and tools, the first-year credits alone often justify it.
Probably not if your customers are households and your inputs are small. Registering effectively raises your prices by 10% against unregistered competitors while giving you little to claim back — plus quarterly BAS obligations.
Cash or accrual, and reporting cycle
Businesses under $10 million turnover can choose cash accounting for GST — you account for GST when money moves rather than when invoices are issued. For businesses that invoice on 30-day terms, cash basis materially improves cash flow, because you're not remitting GST on invoices you haven't been paid for.
Most small businesses report quarterly. Monthly reporting is required above $20 million turnover and optional below it — occasionally worthwhile for businesses in a persistent refund position, such as exporters.
Frequently asked questions
What happens if I registered late?
Registration is backdated to when you were required to register, and you owe GST on sales from that date. Penalties and interest can apply. Voluntary disclosure before the ATO contacts you produces a materially better outcome, and sometimes suppliers can be re-invoiced.
Can I cancel my GST registration?
Yes, if your turnover falls below the threshold and you're not in a category requiring registration. You'll need to account for GST on assets you keep, and you must cancel within 21 days of ceasing business. Cancelling and re-registering repeatedly attracts attention.
Do I charge GST on exports?
Exports of goods are generally GST-free where they leave Australia within the required time and you keep evidence. Services to non-residents can also be GST-free depending on the circumstances — worth checking rather than assuming.
I'm an Uber driver under $75,000 — do I register?
Yes. Ride-sourcing is treated as taxi travel, so GST registration applies from the first dollar. Food-delivery-only riders are subject to the ordinary $75,000 threshold.
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