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When will you cross the GST threshold?

Registration stops being optional at $75,000 of GST turnover, and the clock that starts then is 21 days, not a financial year. Project when you get there, then read what actually changes.

Project when you get there

Enter what you have invoiced so far this year and roughly how fast it is growing. The projection is an estimate to plan against, not a substitute for your own books.

Business income so far this year

Total invoiced by your trade business since 1 July, GST exclusive

Expected monthly growth

Slow 5% Moderate 10% Fast 15%

Your recent trend, not a target

Progress towards $75,000 67%

$0 $75,000 threshold $200,000+

Your registration timeline

Enter your income above

Expected to reach $75,000

21 days after that

Registration deadline

You have time to prepare before GST registration becomes compulsory. Getting your records in order beforehand is what makes the first BAS a check rather than a scramble.

Month by month

Month	Projected income	Cumulative total	Status
The month-by-month projection appears here once the figures above are entered.

Contents

Key takeaways

The threshold is $75,000 of GST turnover, which is gross income, not profit.
It is a rolling test on the current and projected twelve months, not a financial year total.
Once you reach it, or expect to, you have 21 days to register.
Register late and the liability backdates, but your clients have already paid you a price without GST in it.
Registering early buys you credits on purchases and costs you 10% on every price a householder pays.
Once registered you report each quarter, with the next BAS due 28 October 2026.

What counts towards the $75,000#

Two things about the threshold catch people, and both of them cost money rather than time.

It is turnover, not profit. Gross income from the business before any expense comes off it. A year that grossed $80,000 and left $25,000 after materials, fuel and insurance is over the line.
Materials you bill on are in. If you invoice the client for the materials, that is your turnover. What you paid the supplier is an expense and does not net off against it.
It is a rolling twelve months, not a financial year. The test is the current month plus the previous eleven, or the current month plus the next eleven if you expect to reach it.

ATO: registering for GST

The 21 days, and what starts them#

The clock starts the moment your GST turnover reaches $75,000, or the moment you form a reasonable expectation that it will. Not at quarter end, not when your accountant tells you, and not when you get around to checking.

You reach the threshold, or expect to

On the rolling twelve-month test, either looking back or looking forward.
You have 21 days to register

Through the ABR, ATO online services, or your registered agent.
You start charging GST

From your date of registration. Every invoice from then carries 10% and has to meet the tax invoice rules.
You start claiming credits

On business purchases from that date, where you hold the supplier tax invoice.

Registering late does not get you out of it. The ATO can backdate registration to the day you were required to register, and you owe the GST on sales made since. The problem is not the rule, it is the arithmetic: you cannot go back and add 10% to invoices your clients have already paid, so that GST comes out of money you have already spent.

Crossing it mid-year#

Here is the situation the tracker above is really about: a business that is going to cross, and has a choice about when it finds out.

A sole trader growing steadily

Invoiced in the first six months	$42,000.00
Running at roughly	$7,000.00 a month
Projected to reach $75,000 in	Month eleven
Registration deadline	21 days after that
GST on the remaining work once registered	Charged on top of the price

Seeing this in month six rather than month eleven is the whole value of projecting it: there is time to tell clients the price is going up 10%, and time to bring forward a tool purchase so the credit lands in the first quarter.

The same business, found out afterwards

Crossed the threshold in	Month eleven
Noticed at year end, four months later	Registration backdated
Invoiced in those four months	$31,000.00
GST now owed on that work (divide by 11)	$2,818.18
Out of pocket, because those clients already paid	$2,818.18

The clients paid a price with no GST in it and are under no obligation to pay more. The shortfall is the business owner's, and it is roughly a month of income.

Should you register before you have to?#

Below the threshold it is a choice, and the answer turns almost entirely on who pays your invoices rather than on how organised you are.

Voluntary registration, decided on who your customers are.
	Mostly business clients	Mostly householders
Do they feel the 10%?	No, they claim it back	Yes, it is a real price rise to them
Effect on your quotes	Neutral against registered competitors	You are 10% above an unregistered competitor
Credits on tools and materials	Yes, once registered	Yes, once registered
Extra work	A BAS every quarter	A BAS every quarter
Usual answer	Register early, it costs you nothing	Wait unless you are about to buy something substantial

The exception in both columns is a big purchase. If a $30,000 vehicle or a plant upgrade is coming, registering first means claiming the GST on it, which is a real number. ATO: when you can claim a GST credit.

What changes the day you register#

Less than people fear, and in a specific list.

Every invoice carries 10%, and may be headed Tax invoice with your ABN on it. Before registration you may not use that heading at all.
You can claim credits on business purchases where you hold a valid supplier tax invoice.
You lodge a BAS each quarter. The next one falls due 28 October 2026.
The GST you collect stops being yours the moment it arrives, which is the habit worth building before you need it.

Chippie calculates and shows GST on every quote and invoice line as you write it, heads the document correctly, puts your ABN on it, and keeps a running quarterly position with a BAS-readiness score. Lodgement goes through you, your accountant, or Xero. ATO: tax invoices.

The GST threshold: common questions#

Is the $75,000 threshold based on profit or turnover?

Turnover, meaning gross income from your business before any expenses. A business that invoiced $80,000 and cleared $25,000 after materials and fuel is over the threshold, not under it.

Is it measured per financial year?

No, and this is the part that catches people. It is a rolling test: your turnover for the current month plus the previous eleven, or the current month plus the next eleven if you expect to reach it. You can cross in February on a twelve-month window that started the previous March.

What happens if I register late?

The ATO can backdate your registration to the date you were required to register, which means you owe GST on sales made since then. You cannot go back and add 10% to invoices your clients have already paid, so that GST comes out of money you have already spent.

Does my materials spend count towards the threshold?

Only if you invoice it. Turnover is what you charge, so materials you bill on to the client are in. What you paid the supplier is an expense and does not reduce the turnover figure.

What if I go over once and then drop back?

If you are registered and your turnover falls below the threshold you may cancel, but you generally have to have been registered at least twelve months. Cancelling and re-registering repeatedly is not the intent, and there are adjustments on assets you claimed credits for.

Should I register before I have to?

It depends who pays your invoices. Business clients claim the GST back and do not feel it. Householders cannot, so your price effectively rises 10% against an unregistered competitor. Against that, registering lets you claim credits on tools, materials and vehicle costs.

Stop doing this in a spreadsheet

Chippie does the quoting, the invoicing and the GST maths for you.

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