GST Registration for Tradies: When You Need It and How It Works

Most tradies do not think about GST until the work starts coming in thick and fast. Then comes the question everyone puts off for too long: do I actually need to register for GST yet, and what happens if I already should have?

GST registration for tradies is one of the most misunderstood obligations in Australian tax. This guide covers the threshold, the timeline, what registration means for your invoices and cash flow, and when it might actually make sense to register before you are required to.

What Is GST and Who Does It Apply To?

GST stands for Goods and Services Tax. It is a 10% tax applied to most goods and services sold in Australia. As a registered tradie, you add 10% to your invoices, collect that amount on behalf of the government, and pass it on to the ATO through your Business Activity Statement (BAS).

The key thing to understand is that GST is not your money. It passes through your account on its way to the ATO. Tradies who treat that 10% as income run into serious cash flow problems at BAS time.

The $75,000 Threshold: What It Means for Tradies

The rule is straightforward. Once your GST turnover reaches $75,000, you must register for GST. Turnover means your gross business income, not your profit. It is what comes in before expenses.

There are two things that catch tradies out every year.

First, the threshold applies to any rolling 12-month period, not just the financial year. You do not wait until 30 June to tally things up. If you have earned $75,000 in any 12-month window, the clock starts. A tradie who has a strong run from October through September can hit the threshold well before EOFY and not realise it.

Second, once you cross $75,000 you have 21 days to register. Miss that window and the ATO can backdate your registration to the date you crossed the threshold. That means GST is owed on every invoice you sent from that date onwards, even the ones where you never charged the client GST. You absorb that cost out of your own pocket.

The safer habit is to check your rolling turnover each month, not once a year at tax time.

Should You Register Voluntarily Before You Hit the Threshold?

If your turnover is under $75,000, registration is optional. But it is worth thinking through, because there is a genuine upside to registering early.

Once you are registered, you can claim back the GST you pay on business purchases. Tools, materials, fuel, subcontractors, safety gear: if there is GST on the invoice, you can claim it back through your BAS. For tradies who are spending on materials and equipment regularly, those credits add up.

There are also practical reasons around how you present to clients. Some commercial clients and government bodies expect their suppliers to be GST-registered. Arriving at a tender without a GST-registered ABN can cost you work.

The downside is the admin. Once you register, you lodge BAS, you issue tax invoices, and you keep proper records. That is ongoing work. Speak to a tax professional about your situation before deciding, because the right answer depends on your spend level, your client base, and where your turnover is heading.

How to Register for GST

Registering for GST is free. You do it through the ATO’s Online services for business, myGov, or through a registered BAS agent or tax agent who can do it on your behalf. For most sole traders, registration happens through your existing ABN.

Here is what the process looks like from start to finish:

1. Confirm your GST turnover has reached $75,000, or that you want to register voluntarily.
2. Log into myGov and access your ATO online services, or contact a registered agent.
3. Select “Register for GST” and enter your business details, ABN, and preferred BAS lodgement cycle.
4. The ATO confirms your registration and GST start date.
5. From that date, add 10% GST to all taxable invoices and keep records of every purchase with GST included.

Registration is usually processed quickly when done online, though timing can vary.

What Changes Once You Are Registered

Once you are registered, three things change immediately.

Your invoices need to show GST. Every tax invoice must include your ABN, the GST amount (or a statement that the total includes GST), and a description of what was supplied. If you send an invoice without these details, your client cannot claim the GST credit on their end.

You lodge a BAS. The Business Activity Statement is how you report and pay your GST to the ATO. Most tradies with turnover under $20 million lodge quarterly, as set out on the ATO’s BAS due dates page. If you lodge through a registered BAS or tax agent, you may be eligible for an extended deadline.

You keep records for five years. Every tax invoice, receipt, and BAS needs to be kept for a minimum of five years from the date you lodge.

The Biggest GST Mistake Tradies Make

The most common problem we see is tradies spending the GST before the BAS is due.

You invoice $11,000 for a job, bank $11,000, and spend it. Three months later your BAS arrives and $1,000 of that payment belongs to the ATO. Multiply that across a quarter’s worth of invoices and the bill gets very uncomfortable very quickly.

The fix is simple: every time you get paid, set aside the GST portion, one-eleventh of what you’re paid, into a separate account. Treat it as money that was never yours to begin with, because it wasn’t. The same discipline applies to the bookkeeping that sits behind the BAS. When your records are kept properly throughout the quarter, there are no surprises at lodgement time.

At ABBS Tax, our BAS and bookkeeping services are handled by the same team that lodges your tax return, so the numbers that flow into your BAS match your books exactly. There is no gap between your records and what gets reported to the ATO.

Need help with GST registration or your BAS? When you work with ABBS Tax on your sole trader tax return, GST obligations are reviewed as part of the process. You can also see our full range of tax and compliance services or get in touch to talk through your situation. This article is general information only, not tax advice. Speak to a tax professional about your specific situation.