One of the first tax questions most sole traders face is whether they need to register for GST. Get it wrong in either direction and there are consequences: fail to register when you should have, and you'll owe the ATO GST you never collected. Register when you don't need to, and you've added compliance obligations you didn't need yet.

This guide covers the $75,000 threshold, the situations where registration is mandatory regardless of income, how to register once you've decided (or been required), and what changes the moment you're registered.

Quick answer: You must register for GST if your GST turnover is $75,000 or more in any 12-month period (current or projected). There's one critical exception: if you provide ridesharing services (Uber, Ola, Didi), you must register from dollar one — no threshold applies. You need an ABN first, then you can register through ATO online services, by phone, or through a registered tax or BAS agent.

This is general information, not tax advice — see your registered tax agent for your specific situation.

The $75,000 Threshold Explained

The GST registration threshold is $75,000 in annual GST turnover. This is not your net profit — it's your gross revenue from sales of goods and services connected with Australia.

Source: ato.gov.au — Registering for GST

Current vs Projected Turnover: Two Tests

The ATO applies two tests, and you must register if you cross the threshold under either:

Test 1 — Current 12 months: Your GST turnover in the current 12 months (not the financial year — the current month plus the previous 11 months) is $75,000 or more.

Test 2 — Projected 12 months: Your GST turnover for the current month plus the next 11 months is likely to be $75,000 or more.

The projection test catches people out. You can be required to register before you've actually earned $75,000, if it's reasonable to expect you will.

Practical Example: Sarah the Cleaner

Sarah runs a residential cleaning business. In March 2026, her revenue has been consistently $6,500 per month for the past four months.

Projected annual revenue: $6,500 × 12 = $78,000

That's above the $75,000 threshold. Sarah must register for GST now — not when she hits $75,000 in accumulated receipts, but once she can reasonably project crossing the line.

She should register within 21 days of becoming aware she will exceed the threshold.

What Counts as GST Turnover?

GST turnover is your total business income (not your profit), excluding the GST you charged. Taxable and GST-free sales both count. It excludes:

  • Input-taxed supplies (residential rent, financial supplies)
  • Sales not connected with Australia
  • Sales to associates that aren't for payment, and sales not connected with an enterprise you run

When working out your projected turnover, you also leave out sales of capital assets and sales made only because you are closing the business or substantially and permanently reducing its size.

It does NOT subtract your expenses. A cafe doing $300,000 in sales but $280,000 in costs still has $300,000 in GST turnover.

When Registration Is Mandatory Regardless of Turnover

There's one major exception to the $75,000 rule that catches people every year:

Ridesharing Services: GST from Dollar One

If you provide ridesharing or ride-sourcing services — driving for Uber, Ola, Didi, or any similar platform — you must register for GST before you accept your first fare. The $75,000 threshold does not apply.

This is explicit in ATO guidance. The ATO's rule is that anyone providing taxi or limousine travel for passengers must register regardless of turnover, and ride-sourcing is included in that category.

Food delivery is different. Delivering for DoorDash, Uber Eats or Menulog is not ride-sourcing — it's a courier service. The standard $75,000 threshold applies. However, if you're already registered because of ridesharing, you must report and pay GST on all your business income under that ABN, including food delivery.

Non-Profit Organisations

The threshold for non-profits is $150,000 (not $75,000). This doesn't affect most sole traders, but worth knowing if you run a side charitable activity.

Should You Register Voluntarily?

Even if your turnover is below $75,000, you can choose to register for GST voluntarily. There are genuine reasons to do this.

Reasons to Register Voluntarily

Claim input tax credits: Once registered, you can claim back the GST you pay on business purchases. If you're spending $15,000/year (GST-inclusive) on tools, equipment and software from GST-registered suppliers, that's $1,364 in input tax credits you're currently leaving with the ATO.

Look more established: Some clients — particularly larger businesses — prefer to work with GST-registered suppliers. It signals you're running a real operation.

Smooth the transition: If you're growing toward $75,000, registering early means no scramble when you cross the line.

Reasons to Wait

Extra compliance burden: Once registered, you must charge GST on your taxable sales, lodge a BAS (quarterly for most businesses, though annual lodgment is an option if you're voluntarily registered with GST turnover under $75,000), keep records for five years, and generally stay registered for at least 12 months. That's real admin overhead.

Price perception: If your clients are mainly consumers (not businesses), adding 10% GST to your prices can affect competitiveness.

The general rule: if your clients are mostly other businesses who can claim the GST back anyway, voluntary registration often makes sense. If they're mostly consumers, think carefully about whether the input tax credit benefit outweighs the compliance cost.

How to Register for GST

Before you can register for GST, you need an ABN. If you don't have one, apply for an ABN first.

Registering online

  1. Log in to ATO Online services for business (you'll need a Digital ID such as myID)
  2. Go to your tax registrations and choose to add a registration
  3. Select GST and follow the prompts
  4. Provide your business details, expected turnover and start date
  5. You'll receive a confirmation with your GST registration date

Registering by phone

Once you have an ABN, you can phone the ATO's Business enquiries line and register over the phone.

Registering via a BAS or Tax Agent

If you'd rather have someone handle it, any registered BAS agent or tax agent can register you. Ask about their fee before they start.

The ATO will confirm in writing the date your registration takes effect. If you should have registered earlier, you can phone the ATO to ask for your registration to be backdated (backdating is limited to 4 years, except in cases of fraud or evasion).

What Changes After Registration

The day your GST registration takes effect, several things change.

You Must Charge GST on Taxable Sales

Every invoice you issue for a taxable supply must include 10% GST. You need to add it to your prices or absorb it from your existing price — either way, you need to track it separately.

Your Invoices Must Be Tax Invoices

If a customer asks for a tax invoice for a taxable sale over $82.50 (GST-inclusive), you must provide one within 28 days. For sales under $1,000, it must clearly show:

  • Your identity (your name or business name) and your ABN
  • That it's intended to be a tax invoice (printing "Tax Invoice" at the top is the simplest way)
  • Date of issue
  • A brief description of what you sold, including quantity (if applicable) and price
  • The GST amount, shown separately, or (if GST is exactly one-eleventh of the total) the statement "Total price includes GST"
  • The extent to which each item is a taxable sale

For sales of $1,000 or more, the invoice must also show the buyer's identity or ABN.

You don't have to provide a tax invoice for sales of $82.50 or less (GST-inclusive), but give a receipt or invoice anyway: business customers need one to support their GST credit claims on small purchases.

You Must Lodge BAS Quarterly

From registration you'll lodge a BAS quarterly (monthly if your GST turnover is $20 million or more, or annually if you're voluntarily registered with GST turnover under $75,000). See our full BAS lodgment guide for due dates and process.

You Must Keep Records for Five Years

All tax invoices, receipts for business purchases, and BAS lodgment records must generally be kept for five years from when you prepared or obtained the record, or completed the transaction, whichever is later.

How to Deregister from GST

If your turnover drops and stays below $75,000 — and you don't expect to exceed it — you can cancel your GST registration. If you registered voluntarily, you generally need to stay registered for at least 12 months.

To deregister:

  • Cancel through Online services for business, through your registered tax or BAS agent, or by phoning the ATO on 13 28 66
  • Choose your cancellation date: it should be the last day you want to be registered
  • You can't choose a date that falls in a period you've already lodged a BAS for, or a date after which you kept trading as GST-registered

Note: You cannot cancel your GST registration if you're still required to be registered (i.e., your turnover is at or above $75,000 or you're a rideshare provider).

After cancellation, you stop charging GST on sales. You'll only keep getting a BAS if you have other obligations, such as PAYG withholding or PAYG instalments. You'll still need to lodge a final BAS for the period up to your cancellation date.

This is general information, not tax advice. GST registration thresholds and rules can change, and the right answer for your business depends on your specific turnover, business activities and structure. Speak to a registered tax agent or BAS agent before registering or deregistering. Verify current ATO guidance at ato.gov.au before acting.

Tools That Make This Easier

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FAQ

Q: I've exceeded $75,000 but forgot to register. What should I do?

A: Register immediately, then contact a registered tax or BAS agent about your back-dated liability. The ATO can require GST on taxable sales made from when you were required to register, plus general interest charge on the unpaid amount, even if you did not charge GST to customers. Voluntary disclosure before an ATO compliance contact is generally treated more favourably than late disclosure during a review.

Q: Does the $75,000 threshold apply to each financial year, or is it rolling?

A: It's rolling: the current month plus the previous 11 months (current turnover), or the current month plus the next 11 months (projected turnover). It's not reset at 1 July. If you crossed $75,000 between October and October, you need to register regardless of where that period falls in the financial year.

Q: I'm a rideshare driver who earns less than $10,000 a year. Do I still need to register for GST?

A: Yes. The $75,000 threshold does not apply to ride-sourcing services. You must register for GST before you take your first fare, regardless of how much you earn.

Q: If I'm GST-registered but have a GST-free side income (like fresh food sales), do I include that in my turnover calculation?

A: GST-free supplies are included in your GST turnover for the registration threshold test, even though you don't charge GST on them. However, you still lodge a BAS showing those supplies as GST-free.

Q: Can I claim GST back on purchases I made before I registered?

A: Generally no. The ATO's guidance is that you can't claim GST credits for purchases made before you registered for GST. The exceptions are narrow (for example, some pre-establishment costs of a new company), so ask a registered BAS or tax agent before you lodge your first BAS after registering.

Q: I work two jobs — employed part-time and run a side business. Does my employment income count toward the $75,000 threshold?

A: No. The GST threshold applies only to your business (enterprise) income from taxable and GST-free supplies. Your salary as an employee is not included.

Q: What's the penalty for not registering when I should have?

A: The ATO can impose penalties and charge back-dated GST liabilities plus general interest charge on the unpaid amount. The longer you leave it, the larger the liability. If you tell the ATO about the problem yourself (a voluntary disclosure), it takes that into account when deciding penalties.

Q: Do I need to register for GST if I'm a freelancer invoicing overseas clients?

A: Exports of services to overseas clients are generally GST-free, but they still count toward your GST turnover for the registration threshold test. Once registered, you'd show them on your BAS as GST-free supplies. Whether you actually need to register depends on your total turnover.