When Do You Need to Register
for GST in Australia?

For most businesses, the registration threshold is $75,000 in GST turnover. The important detail is that turnover means business income, with specific exclusions, rather than the profit left after expenses. You may also need to register based on expected sales before your actual sales reach the threshold.

Here’s how to approach the decision and what to have ready when you ask for help.

The GST registration threshold

You generally need to register when your business or enterprise reaches the $75,000 GST turnover threshold. For not-for-profit organisations, the threshold is $150,000.

There are exceptions. Taxi and ride-sourcing businesses must register regardless of turnover, and registration is also required if you want to claim fuel tax credits for your business. Once required to register, you generally have 21 days to do so. See the ATO’s GST registration guidance.

Having an ABN does not automatically mean you are registered for GST. They are separate registrations.

Turnover is different from profit

Imagine a small consultancy with $90,000 in relevant business sales and $30,000 in expenses. Its profit is $60,000, but its turnover for this simple example is $90,000. Looking only at profit could cause the owner to miss the registration requirement.

GST turnover excludes certain amounts, including GST in your sales and input-taxed sales. GST-free sales generally count, so selling GST-free goods or services does not automatically remove the need to register.

If you have different income streams, get the calculation checked rather than assuming every deposit counts in the same way.

You need to look backwards and forwards

The relevant periods are rolling 12-month periods, rather than simply the financial year:

• Current GST turnover: the current month and the previous 11 months.
• Projected GST turnover: the current month and the next 11 months.

If current turnover reaches the threshold but projected turnover is below it, registration may not be required, subject to the rules. Special exclusions also apply to projected turnover, including certain capital asset sales. The ATO explains the turnover calculation and tests.

For example, a new business wins ongoing work and reasonably expects $8,000 in relevant sales each month. That projects to $96,000 over 12 months. The owner should check registration now, rather than waiting until $75,000 has already arrived.

Can you register below the threshold

Eligible businesses can register voluntarily. It’s a decision worth discussing: registration may allow eligible GST credits, but it also brings reporting and recordkeeping responsibilities.

Your customers, expenses and pricing all matter. A consumer-facing business may need to think carefully about whether its advertised prices leave room for GST. The Australian Government’s GST registration overview sets out the basics.

What changes when you register

You’ll need to apply the correct GST treatment to sales, maintain supporting records and meet your reporting obligations. Registration does not mean every sale attracts GST: GST-free and input-taxed sales have different treatment.

Before your registration takes effect, review your prices, invoice templates, software settings and process for setting money aside. Check eligible GST credits rather than assuming every business purchase includes claimable GST.

Get clear on GST before it becomes a scramble

At Bookflow, we’re registered tax agents with the Tax Practitioners Board (TPB). We can help you understand whether registration is required and how to keep your bookkeeping organised as your business grows.

Our packages offer clear, easy pricing with regular direct debit payments, so the cost of agreed support is straightforward to plan for.

General information checked on 29 October 2026. GST registration and reporting requirements depend on your circumstances.