GST registration catches out a lot of new businesses, because the trigger isn't the end of the financial year. It's the month your rolling 12-month turnover crosses $75,000, or the day you can see it's going to. Register late and you can owe GST on sales you never charged it on.
This guide explains exactly when you must register, how to measure GST turnover, the special rule for taxi and ride-share drivers, whether registering voluntarily makes sense, and the steps to register and get set up. The figures are current for 2026–27. The $75,000 threshold isn't indexed and hasn't changed since 2007.
When do I have to register for GST?
| Your situation | Do you have to register? | Deadline |
|---|---|---|
| Business with GST turnover of $75,000 or more | Yes | Within 21 days of reaching the threshold |
| Non-profit organisation with GST turnover of $150,000 or more | Yes | Within 21 days |
| New business that expects $75,000 or more in its first 12 months | Yes | From the start (within 21 days of knowing) |
| Taxi, limousine or ride-share driver carrying passengers for payment | Yes, regardless of turnover | Before your first paid trip |
| You want to claim fuel tax credits | Yes (registration is a condition) | Before claiming |
| Business with GST turnover under $75,000 | No, it's optional | Any time |
| Hobby, not a business | No, and generally you can't |
What is GST turnover?
GST turnover is your total business income, not your profit, after leaving out:
- the GST included in your sales
- input-taxed sales (for example, residential rent and most financial supplies)
- sales not connected with an enterprise you carry on
- sales not connected with Australia
- non-taxable sales to associates
GST-free sales, such as basic food, most medical services and exports, do count towards the threshold, even though you don't charge GST on them.
Current turnover and projected turnover
You reach the threshold if either test is met:
- Current GST turnover: this month plus the previous 11 months is $75,000 or more.
- Projected GST turnover: this month plus the next 11 months is likely to be $75,000 or more.
The projected test is what catches new and growing businesses. Sign a 12-month contract worth $90,000 and you're over the threshold today, even if you haven't invoiced a cent.
Projected turnover ignores sales of capital assets (selling your work ute, for example) and sales made because you're closing down or substantially reducing the business. And if your current turnover is over $75,000 but the ATO is satisfied your projected turnover will be under it (a one-off big job, say), you don't have to register.
Key point: If you're not registered, check your rolling 12-month and next-12-month turnover every month. The financial year doesn't matter for this test.
Worked example: a sole trader crossing the line
Hypothetical, round numbers.
Jess starts a mobile dog grooming business in July 2026. She isn't registered for GST.
| Month | Monthly sales | Rolling 12-month total |
|---|---|---|
| July to December 2026 | $5,000 a month | $30,000 by December |
| January to April 2027 | $7,000 a month | $58,000 by April |
| May 2027 | $8,500 | $66,500 |
| June 2027 | $9,000 | $75,500 |
Jess's current turnover reaches $75,000 in June 2027. But by April, with bookings growing and a council contract signed, her projected turnover for May 2027 to April 2028 was clearly over $75,000. In that case she was required to register in April and must apply within 21 days.
If she doesn't register until August, she can be liable for GST from the date she should have been registered: 1/11th of what she charged customers from then on, even though her prices didn't include GST. On about $26,000 of sales between April and August, that's about $2,360 she didn't collect, plus possible penalties. She can claim GST credits on her business purchases for the same period, which softens it, but she can't go back and charge her customers.
The fix is to register as soon as she can see it coming, and set her prices so the GST is covered.
Do taxi and ride-share drivers need to register for GST?
Yes. If you supply taxi travel, which includes ride-sourcing through Uber, DiDi, Ola and similar apps, you must register for GST from your first paid trip, whatever your turnover. That applies whether you own, lease or rent the car.
As a registered driver you:
- need an ABN before you start
- report GST on your fares (the platform usually issues the tax invoices and gives you a summary)
- claim GST credits on the business share of your car costs, fuel, phone and platform fees
- lodge a BAS, usually quarterly
Delivering food or parcels isn't taxi travel. Delivery drivers follow the normal $75,000 rule. Drivers who do both ride-share and food delivery must register (because of the ride-share), and then GST applies to all their business income, including delivery fees.
Should I register for GST voluntarily?
Under $75,000, registration is your choice. Once registered, you generally have to stay registered for at least 12 months.
| Register voluntarily if | Stay unregistered if |
|---|---|
| Most of your customers are GST-registered businesses (they claim the GST back, so your prices don't effectively rise) | Most of your customers are consumers who can't claim GST back |
| You have big start-up costs and want the GST credits back (fit-out, equipment, stock) | Your costs are mostly wages, rent on a home office, or things without GST |
| You'll pass $75,000 within a year or two anyway | You're well under the threshold and it isn't growing |
| You want to look established to corporate clients | You don't want the BAS admin |
| Your sales are mostly GST-free (exports, basic food) and you'd get refunds | Your sales are mostly taxable and your margins are thin |
Registering also affects your instant asset write-off: a GST-registered business tests the $20,000 limit on the GST-exclusive cost, so equipment priced up to about $22,000 including GST can still qualify. Our instant asset write-off guide explains.
Worked example: is it worth it?
Hypothetical, round numbers.
A graphic designer earns $50,000 a year, all from business clients, and spends $8,000 a year on software, equipment and contractors that include GST.
- Registered: she charges $5,000 GST on top of her fees (clients claim it back), pays it to the ATO, and claims about $727 in GST credits on her costs. She's roughly $727 a year better off, less the time spent on four BAS.
- Not registered: no BAS, no GST, and she can't claim back the $727.
For her, registering is marginally worthwhile. Change her clients to consumers and the answer flips: adding $5,000 GST to her prices would cost her work, or come out of her income.
How do I register for GST?
- Get an ABN if you don't have one. Apply through the Australian Business Register. If the GST requirement already applies, you can register for GST in the same application.
- Register for GST through the ATO's Online services for business, by phone, or through your registered tax or BAS agent. Choose your effective date carefully: it's the date you must start charging GST.
- Choose your accounting method. Cash or accruals (see below).
- Choose how often you'll report. Quarterly is the default for businesses under $20 million. Voluntarily registered businesses under $75,000 can choose annual GST reporting.
- Update your prices, quotes and invoices. Your invoices become tax invoices: they need your ABN and the words "tax invoice", and must show the GST. If a business customer asks for a tax invoice for a sale over $82.50 including GST, you must provide it within 28 days.
- Set up your software. In Xero, set GST rates on every account and item, and turn on GST for the right start date. Most GST errors come from the set-up. Our Xero setup service does this properly from day one.
- Put GST aside. A separate account, topped up as customers pay, means your BAS is never a surprise.
- Diarise your BAS dates. See our BAS due dates guide for every 2026–27 date.
The ATO confirms your registration and effective date in writing.
Can I backdate my GST registration?
Yes. You can ask the ATO to backdate registration by up to four years. You'd do this if you should have registered earlier, or if you want to claim GST credits on start-up costs incurred before you registered. Backdating means you owe GST on sales from the backdated date, so work out both sides before asking.
Cash or accruals: which GST accounting method?
| Cash basis | Accruals (non-cash) basis | |
|---|---|---|
| GST on sales reported | When you're paid | When you issue the invoice (or are paid, if earlier) |
| GST credits claimed | When you pay | When you receive the invoice (or pay, if earlier) |
| Who can use it | Aggregated turnover under $10 million (and some others) | Anyone |
| Best for | Businesses whose customers pay slowly | Businesses that pay suppliers slowly, or that want GST matched to their accounts |
Most small businesses choose the cash basis. It means you don't pay the ATO GST on money you haven't collected yet. If you're owed money at the end of a quarter, that's a real cash flow advantage.
When can I cancel my GST registration?
You can cancel if you're no longer required to be registered, for example because your turnover has fallen and is expected to stay under $75,000, or because you've sold or closed the business. If you registered voluntarily, you generally need to have been registered for at least 12 months.
Two things to know before you cancel:
- You may have to repay some GST credits. When you cancel, you generally make an adjustment for assets you still hold that you claimed GST credits on. The repayment is worked out on their market value at cancellation.
- Lodge a final BAS and make sure the cancellation date matches when you stopped charging GST.
If you're selling the business, the sale itself may be GST-free as a going concern. See our selling a business service.
Mistakes we see with GST registration
- Waiting for the end of the financial year to check turnover.
- Ignoring projected turnover when a big contract is signed.
- Ride-share drivers who don't register because they only drive a few hours a week.
- Leaving out GST-free sales when measuring turnover. They count.
- Registering voluntarily with consumer customers and then absorbing 10% of every sale.
- Setting the wrong effective date in the registration, so the first BAS doesn't match the books.
- Charging GST without being registered. If you aren't registered, you can't charge GST, and you can't issue tax invoices.
- Forgetting to cancel after a business shrinks, then lodging nil BAS for years.
How BPAG helps with GST registration
We check your turnover against both tests, tell you whether and when you need to register, model whether voluntary registration pays, and handle the registration and Xero set-up. Then our BAS pre-lodgement check agent reviews your GST coding before every BAS: missing tax invoices, GST claimed where none was charged, and mixed-up GST-free and input-taxed items. Your client manager reviews every BAS before it's lodged. The agent drafts and checks; a qualified accountant signs off. See our BAS and GST service.
If you're deciding on a structure at the same time, it's worth getting both right together, because GST registration follows the entity. Our sole trader vs company vs trust guide covers the choice, and our page for ecommerce and retail businesses covers GST on online sales.
If you're a sole trader comfortably under $75,000 with consumer customers, the simplest answer is often to stay unregistered and keep an eye on your rolling turnover each month. We'll tell you if that's your answer.
Frequently asked questions
Do I need to register for GST if I only earn $30,000 a year driving for a food delivery app?
Food and parcel delivery isn't taxi travel, so the normal $75,000 threshold applies. Below it, registration is optional. Ride-share driving that carries passengers is different: you must register from your first trip, regardless of how much you earn.
Does rent from my investment property count towards the $75,000?
Residential rent doesn't, because it's an input-taxed supply. Commercial rent does count, and a commercial property owner whose rent reaches $75,000 a year must register and charge GST on the rent. Owning a commercial property through a trust or SMSF doesn't change that.
If I register for GST, do I have to put my prices up by 10%?
No, but you have to account for 1/11th of your GST-inclusive price to the ATO. Whether you raise prices depends on your customers. Other businesses can usually claim the GST back, so a 10% increase costs them nothing. For consumers, it's a real price rise, and many sole traders choose to absorb some of it.
I have two small businesses as a sole trader. Do I add them together?
Yes. GST registration is for the entity, so a sole trader's GST turnover includes all their business activities under their ABN. Two businesses run through two different companies are measured separately, but splitting a business between entities to stay under the threshold can be caught by anti-avoidance rules.
Do I need an ABN to register for GST?
Yes. You need an Australian Business Number first. You can apply for an ABN and register for GST at the same time through the Australian Business Register, or register for GST later through the ATO's online services or your tax agent.
Can I register for GST and use cash accounting?
Yes, if your aggregated turnover is under $10 million. Cash accounting means you report GST on sales when you're paid and claim GST credits when you pay, which is usually simpler and better for cash flow if your customers pay slowly.
Official sources
General information only, current as at 18 October 2026. It is not personal tax, legal or financial product advice and doesn't take your circumstances into account. Talk to us before you act. Where a recommendation needs a licensed financial adviser or a solicitor, we work alongside them.