GST Registration Threshold in Australia: The $75,000 Line
When you must register for GST: the short answer
You must register for GST once your business has a GST turnover of $75,000 or more a year. GST turnover is your gross business income, not your profit, and it excludes the GST itself. Two separate tests can trip the threshold: your turnover over the last 12 months (current GST turnover) and your expected turnover over the next 12 months (projected GST turnover). If either reaches $75,000, you have to register, and you have 21 days to do it. Non-profits use a higher $150,000 figure, and taxi, limousine and rideshare drivers must register from the first dollar.
This guide walks through how the ATO measures that turnover, the two-part test most people only half-remember, the special thresholds, and the part worth getting right: what it costs if you cross the line and register late.
What counts as GST turnover (and what does not)
GST turnover is the number that matters, and it is not the number most sole traders check. Per business.gov.au, GST turnover is your business income minus certain sales, and it is not your profit. An online store that sells $80,000 of clothing has to register even if its profit after costs is only $40,000, because the $80,000 is what the test looks at.
A few things are left out of the figure. You exclude the GST you have charged, any sales that are input-taxed (such as residential rent or some financial supplies), sales that are not for payment and not taxable, and sales not connected with running your business. The ATO's guidance on working out your GST turnover also leaves the one-off sale of a capital asset, such as a van or a piece of equipment, out of the projected figure, so selling a vehicle does not by itself push you over.
The practical upshot: add up your sales income, strip out any GST already in those figures, and that running total is what you measure against $75,000.
The two-part turnover test
The ATO does not wait for a tax year to end before the threshold bites. It runs two rolling 12-month tests, and you register if either one reaches $75,000.
| Test | The 12 months it covers | What it asks |
|---|---|---|
| Current GST turnover | The current month plus the previous 11 | Has turnover already reached $75,000? |
| Projected GST turnover | The current month plus the next 11 | Is turnover likely to reach $75,000? |
The projected test is the one people miss. You do not get to wait until your books show $75,000 banked. If you sign a contract in March worth $80,000 over the coming year, your projected GST turnover crosses the line in March, and the clock starts then. The ATO suggests checking each month whether you are likely to go over, rather than reviewing once a year.
Worked example. You invoice about $7,000 a month as a sole trader. For the first few months your current turnover sits well under $75,000, so you are not required to register yet. By month 11 your rolling current turnover reaches roughly $77,000 ($7,000 × 11), which is over the threshold, and you must register within 21 days of the month it crossed. If instead you had landed a single $90,000 project in month one, your projected turnover would have crossed $75,000 immediately, and you would have had to register straight away.
The thresholds: $75,000, $150,000, and $0
The $75,000 figure is the standard one, but it is not the only line.
| Who you are | Register when GST turnover reaches |
|---|---|
| A business or sole trader | $75,000 |
| A non-profit organisation | $150,000 |
| A taxi, limousine or rideshare driver | $0 (register regardless of turnover) |
The rideshare rule catches people out. If you drive for Uber, DiDi or any ride-sourcing service, or provide taxi or limousine travel, you must be registered for GST no matter how little you earn from it, per business.gov.au. A side gig driving on weekends does not get the $75,000 head start that other side gigs do. You also have to register, regardless of turnover, if you want to claim fuel tax credits.
If you are starting out, the test is forward-looking from day one: register if you expect your GST turnover to reach $75,000 in your first year of trading.
The 21-day rule and what late registration costs
Once either turnover test crosses the threshold, you must register for GST within 21 days. The deadline runs from when you become aware, or could reasonably expect, that your turnover will exceed $75,000, not from the day the money arrives.
Miss it, and the cost is real. If you were required to register and did not, the ATO can backdate your registration to the date you crossed the threshold. From that date you are liable for the GST on your sales, which is one-eleventh of each GST-inclusive sale. The sting is that you probably did not add GST to those prices at the time, so you pay that one-eleventh out of your own pocket rather than passing it on. The ATO also warns you may have to pay penalties and interest on top.
Put a number on it. If you kept trading for a year past the point you should have registered and made $90,000 of sales in that window, the backdated GST is about $8,182 ($90,000 ÷ 11) that you now owe but did not collect from customers. You can claim GST credits on your business purchases over the same backdated period, which softens the blow, but the net bill is usually still a nasty surprise. This is why the projected-turnover test matters: it is designed to get you registered before you start making sales you forgot to add GST to.
Should you register voluntarily under $75,000?
You can register for GST before you have to. Whether it is worth it depends on who your customers are and what you buy.
Registering voluntarily lets you claim GST credits on your business purchases, which is money back on the GST built into your laptop, your tools, your software and your stock. If you spend heavily on GST-inclusive inputs, that can add up. It also looks established to business customers, who often expect a tax invoice with GST on it.
The trade-offs are concrete. Once registered, you must add 10% GST to most of what you sell, which either raises your prices or eats into your margin if your customers are consumers who cannot claim it back. You also have to lodge a business activity statement on a schedule and keep GST records that stand up to review. And there is a lock-in: if you register voluntarily, you generally must stay registered for at least 12 months before you can cancel, per the ATO. For a sole trader selling services to other GST-registered businesses, voluntary registration often pays off. For one selling to the public with few GST-inclusive costs, it often does not.
What changes the day you register
Registration flips three things on at once. You register against your ABN through ATO online services for business, through a registered tax agent, or by phoning the ATO on 13 28 66.
From your registration date you must add 10% GST to your taxable sales, issue tax invoices that meet the ATO's requirements, and report it all on a BAS. In return you claim GST credits on your business purchases, so the GST you pay on inputs comes back to you. The BAS nets the two: GST collected on sales, minus GST credits on purchases, equals what you pay the ATO (or what it refunds you).
Common mistakes
Measuring profit instead of turnover. The threshold is gross income, not what is left after expenses. A business with slim margins can sail past $75,000 of turnover while feeling like it is barely breaking even, and it still has to register.
Ignoring the projected test. Waiting until your bank statements show $75,000 banked is the classic error. If a contract or a run of orders makes it likely you will reach the threshold in the coming 12 months, you are required to register now, not at the end of the year.
Forgetting the rideshare rule. Drivers for Uber, DiDi and similar services, and taxi and limousine operators, must register from the first fare. There is no $75,000 cushion for ride-sourcing income.
Not tracking turnover month to month. The test is a rolling 12 months, checked monthly, not a once-a-year calculation. If you only look at the figure when you do your tax return, you can discover you crossed the line months ago and owe backdated GST.
How SparkReceipt helps you watch the line
The hard part of the threshold is not the rule, it is knowing where your rolling turnover sits before it is too late. SparkReceipt keeps your income and expenses in one place so the number stays up to date: it reads receipts and invoices, applies the right tax treatment for the receipt's country (GST, VAT, HST), and files each one as a categorised, GST-aware expense or income record. Its reports total your sales and tax by date range, so checking whether your rolling 12-month turnover is nearing $75,000 is a filter, not a spreadsheet afternoon. Once you do register, the GST on every receipt is already captured and ready for your BAS, and the records sit where the ATO's record-keeping rules expect them. See pricing for plan details, including the free accountant seat.
Frequently asked questions
What is the GST registration threshold in Australia? $75,000 of GST turnover a year for a business or sole trader. Non-profit organisations register at $150,000, and taxi, limousine and rideshare drivers must register regardless of turnover.
Is the $75,000 threshold based on profit or turnover? Turnover. GST turnover is your gross business income, excluding GST and certain sales, not your profit after expenses. A business with $80,000 of sales and $40,000 of profit still has to register.
How long do I have to register once I pass the threshold? 21 days from when you become aware, or could reasonably expect, that your GST turnover will reach $75,000. That includes the projected test, so a large contract can start the clock before the money arrives.
What happens if I register for GST late? The ATO can backdate your registration to the date you crossed the threshold. You then owe GST on sales from that date, one-eleventh of each sale, usually out of your own pocket because you did not charge it at the time, and possibly penalties and interest. You can claim GST credits on purchases over the same period.
Should I register for GST voluntarily if I earn under $75,000? It depends. Voluntary registration lets you claim GST credits on business purchases, which helps if you buy a lot of GST-inclusive inputs or sell to other registered businesses. But you must charge 10% GST, lodge a BAS, and generally stay registered for at least 12 months.
Do Uber and rideshare drivers have to register for GST? Yes. Taxi, limousine and ride-sourcing drivers must register for GST regardless of how much they earn, so the $75,000 threshold does not apply to that income.
Key takeaways
- You must register for GST once your GST turnover reaches $75,000, measured as gross business income excluding GST, not profit.
- Two tests apply and either triggers registration: current turnover (the current month plus the previous 11) and projected turnover (the current month plus the next 11).
- Special thresholds: $150,000 for non-profits, and $0 for taxi, limousine and rideshare drivers, who register regardless of turnover.
- You have 21 days to register after crossing the line, and the deadline runs from when you could reasonably expect to reach it, not from when the money lands.
- Registering late is expensive: the ATO backdates your registration and you pay one-eleventh of past sales as GST, often from your own pocket, plus possible penalties and interest.
- Voluntary registration below $75,000 can be worth it for GST credits, but it commits you to charging GST, lodging a BAS, and staying registered for at least 12 months.