When do I need to register for GST in Australia?

Within 21 days of your GST turnover reaching A$75,000 (A$150,000 for a non-profit). GST turnover is measured two ways: your sales for the current month plus the previous 11 months, or the sales you expect for the current month plus the next 11 months. Reaching A$75,000 on either test means you must register.

Do I need to register for GST as a sole trader?

Only once your GST turnover reaches A$75,000, the same threshold as any other business. Your wages from a job don't count, but sales from all your businesses do, added together. Below A$75,000 you can choose to register. Sole traders who drive for Uber or another ride-sharing service must register from their first fare.

Do overseas sales count towards the A$75,000 GST threshold?

Yes. GST-free sales, including goods you export and services to overseas customers, count towards your GST turnover even though you don't charge GST on them. Input-taxed sales, such as residential rent, don't count, and nor does the GST itself or the sale of your business assets.

Do I need an ABN to register for GST?

Yes, if you're an Australian business. You apply for an Australian business number (ABN) free through the Australian Business Register, and you can register for GST in the same application. Overseas businesses that sell to Australian consumers can use simplified GST registration instead, which gives them an ATO reference number rather than an ABN.

What happens if I register for GST late?

The ATO registers you from the date you should have been registered, and you owe GST on your taxable sales from that date, even if you didn't charge customers for it. On a GST-inclusive price that's one-eleventh of the sale. You may also face penalties and the general interest charge. Registering as soon as you notice limits the damage.

Can I register for GST if I earn less than A$75,000?

Yes. Voluntary registration lets you claim back the GST on your business purchases and charge GST to business customers who can claim it themselves. The downsides are the extra paperwork and 10% on top of your prices for consumers. Once registered voluntarily, you generally have to stay registered for at least 12 months.

Register for GST in Australia: When and How

Short answer: you must register for GST within 21 days of your GST turnover reaching A$75,000 (A$150,000 for non-profits), measured over the last 12 months or the next 12. All your sales count, including GST-free exports. You need an ABN first, and you can apply for both at once on the Australian Business Register. Below A$75,000, registering is optional. Overseas businesses use a separate, simplified registration.

This guide is for Australian sole traders, partnerships and companies selling online or in person. It’s current as of 12 November 2026.

Do you need to register for GST? Find your situation

You are…	Register for GST?	When
A sole trader or company with GST turnover under A$75,000, and not expecting to reach it	No, unless you choose to	Optional
At A$75,000 or more over the last 12 months	Yes	Within 21 days of reaching it
Expecting to reach A$75,000 over the next 12 months (a new contract, a big launch)	Yes	Within 21 days of expecting it
A non-profit under A$150,000	No, unless you choose to	Optional
A taxi, Uber or other ride-sharing driver	Yes, whatever your turnover	Before your first fare
Claiming fuel tax credits	Yes, whatever your turnover	Before you claim
An overseas business selling to Australian consumers	Yes, once those sales reach A$75,000	See selling from overseas
Earning wages from a job, plus a small side business	Only the side business’s sales count	When they reach A$75,000

The two A$75,000 tests

The ATO looks at your GST turnover two ways, and reaching A$75,000 on either means you must register:

Test	Which months	Example
Current GST turnover	This month plus the previous 11	In November 2026: December 2025 to November 2026
Projected GST turnover	This month plus the next 11	In November 2026: November 2026 to October 2027

The current test catches steady growth. The projected test catches a jump: if you sign a A$90,000 contract or launch with A$100,000 of pre-orders, you must register now, not a year later when the sales have happened.

Check both every month. The 12-month window rolls, so a strong November and December can push you over even when your financial year’s total is lower.

What counts towards GST turnover

Counts	Doesn’t count
Sales from all your businesses, added together	The GST itself, once you’re registered
Taxable sales in Australia (at the price before GST)	Input-taxed sales, such as residential rent and financial services
GST-free sales, including exports and services to overseas clients	Sales of your business’s capital assets, such as equipment or a vehicle
Sales through Shopify, Etsy, Amazon, eBay and markets	Sales made only because you’re closing the business down
Wholesale and business-to-business sales	Wages, interest, gifts and hobby income

Worked example: two sole traders in Brisbane

Ava sells handmade jewellery on Etsy and her own Shopify store. Her rolling 12-month sales are A$68,000: A$52,000 in Australia and A$16,000 to the US, UK and New Zealand. All of it counts, so she’s at A$68,000, under the threshold. If December lifts her 12-month figure past A$75,000, she has until 21 January to register.

Sam is a freelance web developer earning A$40,000 a year from Australian clients. In March he signs a 10-month A$5,000-a-month retainer with a London agency. His projected turnover for the next 12 months is now about A$90,000 (A$40,000 + A$50,000), so he must register within 21 days, even though the London work is GST-free. Registering lets him claim GST back on his laptop and software, and he only adds 10% to his Australian clients’ invoices.

What you need before you start

An ABN (Australian business number). It’s free, from the Australian Business Register. You can tick GST in the same application.
Your tax file number (TFN), and for a company its ACN.
A Digital ID (myID) to use the ATO’s online services, linked to your business through Relationship Authorisation Manager (RAM) if you’re a company or partnership.
The date you reached, or will reach, A$75,000. That’s your date of effect.
Your choices for how often to report (quarterly for most) and whether to account for GST on a cash or accruals basis.

How to register for GST

Apply for an ABN if you don’t have one, and register for GST in the same application on abr.gov.au.
If you already have an ABN, register for GST through the ATO’s online services (myGov for sole traders, Online services for business for companies and partnerships), by phone on 13 28 66, or through a registered tax or BAS agent.
Choose your date of effect. If you’re registering because you reached A$75,000, it’s the date you reached it. You can backdate.
Pick your reporting period. Quarterly is the default for businesses under A$20 million. Choose monthly if you expect regular refunds, for example as an exporter.
Pick cash or accruals. Under A$10 million turnover you can report GST when you’re paid (cash), which keeps you from paying GST on invoices customers haven’t settled.
Wait for confirmation. The ATO confirms your registration and your first BAS appears in your online services account.

After you register: what to set up

Turn on GST in your store. In Shopify, WooCommerce or BigCommerce, switch on GST collection for Australia and enter your ABN. Decide whether your prices already include GST (most consumer brands keep round prices) or go up by 10%.
Update your invoices. Business customers need a tax invoice showing your ABN for anything over A$82.50.
Keep overseas orders at 0%. Exports stay GST-free. Make sure your store doesn’t add GST to orders shipped outside Australia.
Diarise your first BAS. See BAS due dates.
Claim GST on your costs from your registration date, keeping tax invoices for purchases over A$82.50.

Registering late

If you should have registered and didn’t, the ATO registers you from the date you should have. You then owe GST on every taxable sale since that date, whether or not you charged it. If your prices didn’t include GST, the ATO treats them as if they did: you owe one-eleventh of each sale.

Example: Ava (above) should have registered from 1 January 2026 but notices in October. Her taxable Australian sales since January are A$44,000, so she owes A$4,000 (A$44,000 ÷ 11), less GST credits on her purchases since then, plus the general interest charge. Telling the ATO yourself, before it contacts you, usually means lower penalties.

Voluntary registration: worth it?

Register voluntarily if…	Stay unregistered if…
Most of your customers are GST-registered businesses that claim the GST back	You sell mainly to consumers, who’d pay 10% more
You export a lot and pay GST on your costs (you’d get refunds)	Your costs are low and mostly GST-free
You’ve just started and expect to pass A$75,000 within the year	You’re comfortably under A$75,000 and don’t want a BAS

Once registered voluntarily, you generally have to stay registered for at least 12 months, and you can lodge your GST annually instead of every quarter while you’re under A$75,000.

Cancelling your GST registration

If you close or sell the business, you must cancel within 21 days.
If your turnover drops below A$75,000, you can cancel, after at least 12 months registered if you joined voluntarily.
Lodge a final BAS, and pay back GST credits you claimed on stock and assets you still hold when you cancel.

Official sources

Registering for GST, Australian Taxation Office
Apply for an ABN, Australian Business Register
Due dates for lodging and paying your BAS, Australian Taxation Office