How to Register for GST as a Sole Trader in Australia

Last update: Jan. 28, 2025

What Is GST and How Does It Affect Sole Traders?

Goods and Services Tax (GST) is a 10% tax applied to most goods and services sold in Australia. Once registered, you collect GST on behalf of the ATO — adding 10% to your taxable sales, periodically remitting the collected GST to the ATO, and offsetting it against any GST you have paid on legitimate business expenses (your GST credits).

For a sole trader, GST has three key practical impacts:

• Your prices increase by 10% for clients who are not GST-registered — a consideration for consumer-facing businesses
• You must issue proper tax invoices on all sales of $82.50 or more (including GST) — failure to do so is a compliance breach
• You must lodge BAS regularly — reporting GST collected, GST credits claimed, and any PAYG obligations to the ATO on a set schedule

The upside: once registered, you can claim GST credits on all eligible business expenses — equipment, software, professional services, vehicles, and more — reducing your net GST liability and improving cash flow management.

When Must a Sole Trader Register for GST?

The GST registration obligation is triggered by a single key figure: $75,000 in annual GST turnover. This is not your profit — it is your gross business income before expenses and before tax, measured on a rolling 12-month basis, not a financial year basis.

Critically, the obligation is triggered by either of the following:

• Current GST turnover: your total business income over the current month plus the previous 11 months has reached $75,000
• Projected GST turnover: your total business income over the current month plus the next 11 months is reasonably expected to reach $75,000

This rolling calculation is the most misunderstood aspect of GST for sole traders. Many assume they can wait until the end of the financial year to assess their position — but the threshold applies every single month on a rolling basis. A tradesperson in Brisbane who has a particularly strong quarter, or a freelancer in Melbourne whose client load suddenly doubles, may cross the threshold mid-year without realising it until it is too late.

The 21-Day Rule — Non-Negotiable

Once you know — or reasonably should know — that your GST turnover will reach $75,000, you have exactly 21 days to register for GST. The ATO does not accept "I didn't realise" as a defence once the numbers are clear. Late registration triggers backdated liabilities: the ATO can require you to pay GST on all income earned since you should have registered — even if you never charged your clients GST. That shortfall comes entirely out of your pocket.

Mandatory Registration Regardless of Turnover

There is one important exception to the $75,000 rule: if you provide ride-share, taxi, or limousine services (including platforms such as Uber), you must register for GST before your very first trip, regardless of your annual turnover.

Should You Register for GST Voluntarily Below $75,000?

Sole traders earning below $75,000 can choose to register for GST voluntarily — and in some circumstances, it is the strategically smarter move. However, voluntary registration is not right for everyone.

Reasons to Register Voluntarily

• You have significant GST-creditable expenses: if you spend heavily on equipment, subcontractors, software, or vehicles, claiming GST credits can meaningfully improve your cash flow
• Your clients are GST-registered businesses: B2B clients often prefer or expect GST-registered suppliers — it signals operational maturity and enables them to claim their own input tax credits
• You are approaching the threshold rapidly: if growth projections suggest you will cross $75,000 within a few months, registering early avoids a rushed last-minute application
• You operate in tender-based or contract work: some government contracts and large corporate procurement processes require GST registration as a condition of eligibility

Reasons to Wait Until Mandatory

• You serve consumers directly: adding 10% GST to your prices makes you less competitive against non-registered sole traders in consumer markets
• Your expenses are minimal: if you have few GST-creditable business costs, the benefit of claiming credits does not justify the BAS lodgement burden
• Your turnover is well below threshold with no growth trajectory: voluntary registration creates ongoing compliance obligations that may outweigh any benefit

What You Need Before Registering for GST

Before completing your GST registration, you must have these essentials in place:

• An active ABN — you cannot register for GST without one. If you do not yet have an ABN, register your ABN and GST simultaneously through ABN Registrar at abnregistrar.com.au/abn-tfn-gst-registration-form. This is always the most efficient approach.
• Your business activity details — including the nature of your services, your primary operating location, and an estimate of your current and projected annual turnover
• Your preferred BAS reporting frequency — most sole traders begin with quarterly reporting
• Your business bank account details — for ATO payment and refund purposes

Step-by-Step: How to Register for GST as a Sole Trader

Step 1 — Confirm Your GST Turnover Position

Calculate your current rolling 12-month GST turnover and your projected turnover for the next 12 months. Remember: GST turnover is your gross business income before expenses — not your profit. If either figure meets or will meet $75,000, you are required to register within 21 days.

Step 2 — Ensure Your ABN Is Active and Up to Date

Your ABN must be active and your business details current before GST registration can be processed. If you need to register your ABN as a sole trader first, do so through ABN Registrar — or register both your ABN and GST together in a single session to save time.

Step 3 — Complete Your GST Registration with ABN Registrar

Visit abnregistrar.com.au/abn-tfn-gst-registration-form to register for GST with expert support. ABN Registrar's team ensures your registration is submitted accurately, your reporting frequency is correctly selected, and your registration is aligned with your ABN and TFN records — eliminating the risk of processing errors that trigger ATO follow-up.

Step 4 — Select Your BAS Reporting Frequency

You will be asked to nominate how often you will lodge your Business Activity Statement:

• Quarterly (recommended for most sole traders): lodge four times per year; standard due dates are 28 October, 28 February, 28 April, and 28 July
• Monthly: required if your GST turnover exceeds $20 million; optional for others who prefer more frequent reconciliation
• Annually: only available for voluntarily registered businesses that meet specific ATO eligibility criteria

Step 5 — Receive Confirmation and Update Your Invoices

Once your GST registration is approved, your GST status is linked to your ABN and becomes publicly visible. From this point forward, you must add 10% GST to all taxable sales and issue compliant tax invoices on sales of $82.50 or more. Update all your invoice templates immediately — charging GST before registration or failing to charge it after registration are both ATO compliance breaches.

What Are Your Obligations After GST Registration?

GST registration is not a one-time event — it creates ongoing obligations that must be managed carefully to stay ATO-compliant.

Charging GST on Taxable Sales

Once registered, you must add 10% GST to the price of all taxable goods and services. For example: if you charge $1,000 for a service, your tax invoice must show $1,000 + $100 GST = $1,100 total. Your ABN must appear on all tax invoices.

Lodging BAS on Time

Your Business Activity Statement reports the GST you have collected from clients, minus the GST credits you have accumulated from business purchases, with the net amount either paid to or refunded by the ATO. Late BAS lodgement attracts Failure-to-Lodge (FTL) penalties of $330 per 28-day period (or part thereof), up to a maximum of $1,650 for small entities. These penalties accumulate quickly — a single missed quarter can generate significant fines.

Claiming GST Credits

For every legitimate business expense on which you have paid GST, you can claim a GST credit (also called an input tax credit) to offset your GST liability. Valid credits require a proper tax invoice from the supplier. Common creditable expenses for sole traders include:

• Business equipment and tools
• Software subscriptions and digital services
• Professional services (accounting, legal, consulting)
• Business vehicle costs (proportionate to business use)
• Office supplies and operating expenses

Record-Keeping for Five Years

The ATO requires all GST-registered businesses to retain records for a minimum of five years. This includes all tax invoices issued and received, BAS statements, bank records, and expense receipts. Digitising your records using cloud accounting software and attaching receipts directly to transactions is the most ATO-defensible approach in 2026.

What Counts as GST Turnover — and What Doesn't?

Correctly calculating your GST turnover is essential — and it is not simply your total income. Here is what to include and exclude:

Include in GST Turnover

• All taxable sales and services connected to your business
• GST-free sales (e.g., certain exported services, basic foods) — these count toward the threshold even though GST is not charged on them
• Gross income before expenses and before tax

Exclude from GST Turnover

• GST you collect from customers (the 10% component itself)
• Input-taxed sales (e.g., residential rent, certain financial supplies)
• Sales of personal assets not connected to your business
• Salary and wages if you are also an employee
• Hobby income that does not constitute a business enterprise

Important: high business expenses do not reduce your GST turnover. A sole trader who earns $100,000 and spends $80,000 on subcontractors still has a GST turnover of $100,000 — well above the registration threshold.

Common GST Mistakes Sole Traders Must Avoid in 2026

• Missing the rolling threshold. Tracking income annually rather than monthly is the most common mistake. The $75,000 threshold applies every month on a rolling basis — not just at 30 June.
• Charging GST before being registered. You cannot legally charge GST until your registration is active. Doing so without registration can trigger ATO penalties and require repayment of amounts incorrectly collected.
• Failing to set aside GST collected. The GST on your invoices is not your income — it belongs to the ATO. A dedicated GST holding account prevents the common trap of spending GST funds before BAS is due.
• Lodging BAS late or not at all. FTL penalties accumulate at $330 per 28-day period. Missing two consecutive quarters can cost a sole trader over $1,300 in penalties before a dollar of GST is even assessed.
• Claiming GST on personal expenses. Only expenses directly related to your business activity are eligible for GST credits. Mixing personal and business expenses is one of the leading triggers for ATO review.
• Not cancelling GST registration when eligible. If your turnover permanently drops below $75,000, you can cancel your GST registration and eliminate the BAS lodgement burden. Failing to do so means ongoing compliance costs with no benefit.

Frequently Asked Questions

When must a sole trader register for GST in Australia?

A sole trader must register for GST once their annual GST turnover reaches or is reasonably expected to reach $75,000 in any rolling 12-month period. Registration must be completed within 21 days of becoming aware the threshold will be crossed. Ride-share and taxi drivers must register regardless of turnover, before their very first trip. Missing the 21-day window exposes you to backdated GST liabilities — meaning you owe GST on income you may never have charged your clients.

Can a sole trader register for GST voluntarily below $75,000?

Yes. Sole traders can register for GST voluntarily even if their turnover is below the $75,000 threshold. This can be beneficial if you have significant GST-creditable business expenses or if your clients expect GST-registered invoices. However, voluntary registration creates full BAS lodgement obligations — quarterly reporting, tax invoice compliance, and five-year record-keeping — so the ongoing compliance commitment must be carefully weighed before registering below the mandatory threshold.

What is a BAS and how often do sole traders need to lodge one?

A Business Activity Statement (BAS) is the form used to report and pay GST, PAYG withholding, and PAYG instalments to the ATO. Most sole traders lodge BAS quarterly. The standard quarterly due dates are 28 October, 28 February, 28 April, and 28 July. Businesses with GST turnover exceeding $20 million must lodge monthly. Some very small businesses with ATO approval may lodge annually. Late BAS lodgement attracts Failure-to-Lodge penalties of $330 per 28-day period, so staying on schedule is non-negotiable.

Ready to Register for GST as a Sole Trader?

GST registration is one of the most consequential steps in your sole trader journey — get the timing wrong and you face backdated liabilities; get the process wrong and you face ongoing compliance headaches. Whether you are a builder on the Gold Coast approaching $75,000, a consultant in Sydney whose client base is growing fast, or a Melbourne-based contractor registering GST alongside your ABN, getting expert support from the outset makes all the difference.

Register your ABN, TFN, and GST together through ABN Registrar today — fast, accurate, and handled by experts who ensure your registrations are aligned and ATO-compliant from day one.

👉 Register Your GST Now — ABN Registrar