How to Register for GST in Australia (and the $75,000 Threshold)

Short answer: You must register for GST within 21 days once your GST turnover reaches $75,000, whether that’s your last 12 months or what you expect over the next 12 ($150,000 for non-profits). Taxi, limousine and ride-sourcing drivers must register before their first trip, whatever they earn. You need an ABN first, and registering is free: do it through the Business Registration Service, ATO Online services for business, by phoning the ATO on 13 28 66, or through a registered tax or BAS agent. From your registration date you add 10% GST to taxable sales, issue tax invoices, claim GST credits and lodge a BAS.

The ATO sets the registration rules, and the threshold and 10% rate are the same for the 2025–26 and 2026–27 income years. This guide is for sole traders and small businesses deciding whether, when and how to register. If GST itself is new to you, start with what GST is. If you don’t have an ABN yet, apply for one first.

When do you have to register for GST?

You have to register within 21 days of reaching the GST turnover threshold, which is $75,000 for most businesses. Some businesses must register whatever their turnover.

Situation	Do you have to register?
Current GST turnover (this month plus the previous 11) is $75,000 or more	Yes, within 21 days
Projected GST turnover (this month plus the next 11) is $75,000 or more	Yes, within 21 days
Non-profit organisation with GST turnover of $150,000 or more	Yes, within 21 days
You provide taxi, limousine or ride-sourcing travel	Yes, before your first trip, regardless of turnover
You want to claim fuel tax credits	Yes, GST registration comes first
GST turnover under $75,000	No, but you can register voluntarily

The test runs month by month, not by financial year, so check your turnover every month while you’re unregistered. There’s one relief: if your current GST turnover is at or above $75,000 but your projected GST turnover is below it, you don’t have to register.

How do you work out your GST turnover?

GST turnover is your total business income, not your profit, minus a few specific items.

The ATO’s definition takes your gross business income and leaves out:

• GST included in your sales
• input-taxed sales, such as residential rent
• sales not connected with an enterprise you run
• sales to associates that aren’t for payment and aren’t taxable
• sales not connected with Australia

GST-free sales, such as exports or most medical services, still count towards your turnover.

Example: current turnover. An electrician invoiced $68,400 between August 2025 and June 2026, then $7,900 in July 2026. On 31 July her current GST turnover is $76,300, so she has reached the threshold and must register within 21 days. It doesn’t matter that her profit was about half that.

Example: projected turnover. In October 2026 a software tester signs a 12-month contract at $6,500 a month, starting that month. October plus the next 11 months comes to $78,000, so his projected GST turnover has reached the threshold and he must register within 21 days, even though he hasn’t billed anything yet.

Should you register for GST voluntarily?

Register voluntarily if most of your clients are GST-registered businesses or you have large business purchases. Think twice if you sell mainly to households.

	Registering below $75,000
For	You claim GST credits on tools, equipment, software and fuel
For	GST-registered clients claim back the GST you charge, so it costs them nothing in the end
For	You can choose annual GST reporting while you stay under $75,000
Against	Household customers pay 10% more, or you absorb one-eleventh of your price
Against	You issue tax invoices and lodge a BAS or annual GST return
Against	You generally have to stay registered for at least 12 months

Two sole traders on $50,000 a year show the difference. A graphic designer whose clients are all GST-registered businesses adds $5,000 of GST, which her clients claim back, and she claims the GST on her $3,300 laptop. A dog groomer who serves households either raises prices by 10% or keeps them and hands about $4,545 a year to the ATO ($50,000 ÷ 11), less whatever credits he can claim on his purchases. For the designer, registering costs almost nothing; for the groomer, it’s a real cost.

How do you register for GST?

Register through one of four free channels once you have an ABN.

1. Check your ABN. You need one before you can register for GST. If you don’t have one, you can apply for an ABN and GST together.
2. Choose how to register. Use the Business Registration Service, ATO Online services for business if you already have an ABN, the ATO’s business enquiries line on 13 28 66, or your registered tax or BAS agent.
3. Choose the date your registration starts. If registration became compulsory, use the date you reached the threshold. If you’re registering voluntarily, choose the date you want to start charging GST.
4. Choose your accounting method. On a cash basis, open to businesses with aggregated turnover under $10 million, you report GST in the period you’re paid. On a non-cash (accruals) basis, you report it in the period you invoice or are paid, whichever comes first.
5. Choose how often you report. Quarterly is the usual choice for a sole trader, and you can opt for monthly. Annual reporting is open only to voluntary registrants under the threshold. Ride-sourcing drivers can’t choose annual reporting.
6. Keep the confirmation. Your GST status then shows on ABN Lookup, where clients can check it.

What if you should have registered earlier?

The ATO can backdate your registration to the date it became compulsory, by up to four years. You then owe GST on your sales from that date, even though you didn’t charge it.

Because you didn’t add GST, the ATO treats the GST as one-eleventh of what you charged. Say a plumber reached the threshold in March but didn’t register until September, and invoiced $44,000 in between. He owes $4,000 of GST out of money he has already banked. Backdating works both ways, so he can also claim GST credits on business purchases from the backdated date, provided he holds the tax invoices. Penalties and interest can apply on top, so register as soon as you notice, and talk to a registered tax agent if you’re well past the date.

What changes on your prices and invoices?

From your registration date, you include GST in the price of taxable sales and issue tax invoices. You’ll also need to decide whether to raise your prices or absorb the GST.

• Prices. A $2,400 job becomes $2,640 if you pass the GST on. When you advertise to consumers, the total price must include GST, so update your website and price lists. For quotes a client has already accepted at a set price, check whether the quote said “plus GST” before you add it, and talk to the client if it didn’t.
• Invoices. Your invoices become tax invoices. For a sale under $1,000, a tax invoice must show that it’s intended to be a tax invoice, your identity and ABN, the date, what you sold with quantity and price, the GST amount and how much of each sale is taxable. For $1,000 or more, add the buyer’s identity or ABN. If a customer asks for a tax invoice, you must provide one within 28 days, unless the sale was $82.50 or less including GST. How to invoice as a sole trader has the full checklist, and how to calculate GST covers the maths and rounding.
• Purchases. Ask your suppliers for tax invoices. You need one to claim a credit on any purchase over $82.50 including GST.

What changes at BAS time?

You start lodging a business activity statement, usually quarterly, due on 28 October, 28 February, 28 April and 28 July.

On each BAS you report your total sales at G1, the GST on sales at 1A and the GST credits on purchases at 1B, then pay the difference or receive a refund. You only account for GST on sales from your registration date, so a registration that starts on 15 August puts about six weeks of sales on your July–September BAS. Set aside one-eleventh of every payment you receive as you go. What a BAS is explains the form, and how to do a BAS walks through a quarter.

If your turnover later falls below the threshold, you can cancel your GST registration. That’s subject to the 12-month minimum if you registered voluntarily.

What do you need to keep, and where does Keel fit?

Once you’re registered, every GST figure has to be backed by an invoice you issued or a tax invoice you received, kept for five years.

Keel: Invoice Maker & Receipts, by Ilura Technology OÜ, is an iPhone app for those records. You write estimates, and an accepted estimate becomes the invoice in one tap. Invoices are PDFs, and every quote, receipt, expense and invoice is kept under its job, with your business mileage alongside. A “who owes you” list drafts reminders that you review and send yourself. Records stay on your iPhone: no account, no bank connection, no cloud sync, and the App Store privacy label reads “Data Not Collected”.

Keel doesn’t register you for GST, work out what you owe, lodge your BAS or connect to the ATO. It keeps the documents those tasks depend on. It’s free with no invoice limit, and free invoices carry a small “Made with Keel” footer. Keel Lifetime is a one-time purchase ($249.99 USD; the App Store shows your local price) that adds custom branding, a signature, premium templates and accountant-ready exports. Keel on the App Store. More in the Australia guides.

Frequently asked questions

Do I need to register for GST as a sole trader? Only once your GST turnover reaches $75,000, counting either this month plus the previous 11 or this month plus the next 11, or if you drive a taxi, limousine or ride-sourcing vehicle. You then have 21 days to register. GST turnover is gross business income, not profit. Below the threshold, registering is optional.

Is it free to register for GST? Yes. Registering through the Business Registration Service, ATO Online services for business or the ATO’s 13 28 66 line costs nothing. A registered tax or BAS agent may charge for their time. Websites that charge a fee just to submit the form aren’t the government.

Can I register for GST without an ABN? No. You need an ABN before you can register for GST. If you don’t have one, you can apply for an ABN and GST at the same time through the Business Registration Service at register.business.gov.au.

Do rideshare drivers need to register for GST? Yes. Anyone providing taxi, limousine or ride-sourcing travel must be registered for GST before their first trip, regardless of how much they earn. The $75,000 threshold doesn’t apply. Ride-sourcing drivers also can’t choose annual GST reporting, so they lodge a BAS each quarter or month.

What happens if I don’t register for GST on time? The ATO can backdate your registration to the date it became compulsory, by up to four years. You then owe GST on your sales from that date, worked out as one-eleventh of what you charged, even though you never added it. Penalties and interest can apply.

Can I register for GST if I earn less than $75,000? Yes. Voluntary registration is open to any business with an ABN. You’ll charge GST, claim credits, issue tax invoices and report to the ATO, and you generally have to stay registered for at least 12 months. If your turnover stays under $75,000, you can choose to report GST once a year instead of quarterly.

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This article is general information, not tax advice. Consult a qualified Australian tax professional.