ABN and GST for personal trainers Australia: the basics

Nobody gets certified as a personal trainer because they love tax administration, but the moment you start earning money independently, ABN and GST become part of the job whether you’re ready for them or not.

The good news: for most newly certified fitness professionals, sorting out an ABN for fitness instructor work is simpler than the acronyms suggest. This guide covers the basics in plain English: what an ABN is, when GST actually kicks in, and how to keep yourself out of trouble without needing an accounting degree. If you’re mapping out what else to sort early on, see the full next-steps guide for newly certified fitness professionals.

One important note up front: this is general information, not personal tax advice. Everyone’s situation is different, and for anything specific to your circumstances, a registered tax agent or accountant is the right person to ask, not a blog post.

Quick answer

Independent fitness professionals in Australia who are carrying on a business (rather than working purely as an employee) generally need an Australian Business Number (ABN), which is free to apply for at abr.gov.au. GST registration is only required once your GST turnover reaches $75,000 in a rolling 12-month period (current or projected); below that, registration is optional. Once GST-registered, you must add 10% GST to your prices, issue tax invoices, and lodge Business Activity Statements (BAS). This is general information only. Consult a registered tax agent or accountant for advice specific to your situation.

Do independent fitness trainers need an ABN?

Generally, yes. An Australian Business Number is an 11-digit identifier the ATO uses to recognise you as running a business, rather than being someone’s employee. If you’re training clients independently, taking payment directly, or contracting your services to a studio or gym (as opposed to being on their payroll), you’re carrying on a business in the ATO’s eyes and should register.

It’s worth doing before your first invoice. If you invoice a business without an ABN, that business is required to withhold 47% of the payment as “no-ABN withholding” and send it to the ATO on your behalf. Say you cover a few classes for a studio and invoice them $300 — without an ABN, they'd have to hold back $141 and pay you $159, not the full $300. You can eventually claim that $141 back when you lodge your tax return, but until then it's sitting with the ATO instead of in your account; getting your ABN sorted early avoids this entirely.

Applying is free, done directly through the Australian Government at abr.gov.au, and approval is often instant. If your details can’t be verified immediately, though, the Australian Business Register may take up to 20 business days to review your application (as at July 2026), so it’s worth applying well before you need to invoice anyone. Avoid third-party sites that charge a fee to “process” your ABN application: the official channel doesn’t charge for the ABN itself.

GST: the $75,000 threshold

This is the number that causes the most confusion, so here it is plainly: you’re only required to register for GST once your GST turnover reaches $75,000 in a 12-month period. Below that, registration is optional.

The $75,000 figure is your gross income before expenses, not your profit.
It’s calculated on a rolling 12-month basis, not a financial year: it’s your current month plus the previous 11 months, or your current month plus the projected next 11, whichever hits the threshold first.
If you cross it (or reasonably expect to), you have 21 days to register.
Below the threshold, you can still register voluntarily. Some sole traders do this so they can claim back GST on business purchases like equipment. It doesn’t automatically mean more frequent reporting either: voluntarily registered businesses under $75,000 turnover can generally elect to lodge their BAS annually rather than quarterly, so check your reporting options with the ATO or a tax agent when you register.

For most newly certified trainers building a client base from scratch, GST won’t be an immediate concern: you’re unlikely to hit $75,000 in your first few months. But it’s worth checking your rolling total periodically once you’re established, rather than assuming a financial-year reset will save you; the ATO doesn’t calculate it that way.

What changes once you’re GST-registered

You add 10% GST to your prices, or absorb it into your existing price and treat it as GST-inclusive. Deciding this deliberately matters for how you price your sessions, so it’s worth doing on purpose rather than by accident.
You issue tax invoices instead of ordinary invoices. These need specific details, including your ABN and the GST amount.
You lodge a Business Activity Statement (BAS) regularly (usually quarterly) reporting GST collected and GST paid on business expenses.
You can claim GST credits on eligible business purchases: insurance, equipment, a booking platform, professional development.

Income tax: the part that’s separate from GST

Most trainers in the industry are registered as a sole trader. As a sole trader, there’s no separate “business tax rate.” Your business profit is simply added to your individual income and taxed at your normal marginal rate. If you’re also doing some employed or contract hours elsewhere, your fitness income stacks on top of that for tax purposes, so it helps to understand both sides: see our guides to employed vs self-employed work for fitness professionals and to what personal trainers and fitness instructors actually earn in Australia.

The habit that saves the most stress

Set aside a portion of every payment you receive as it comes in, rather than treating your full invoice total as spendable income. Many sole traders start with a rule of thumb around 20–30%, then adjust once they know their actual marginal rate. It’s the single most common regret independent trainers report: spending the tax portion before BAS or tax time arrives.

A simple starting checklist

Register for your ABN at abr.gov.au before your first invoice.
Track your rolling 12-month turnover so you know when you’re approaching $75,000.
Decide upfront whether your listed prices are GST-inclusive or exclusive (once registered).
Set aside a consistent percentage of every payment for tax as it lands, in a separate account.
Keep records of income and business expenses (insurance, First Aid renewals, equipment, a booking/payment platform). Most are deductible, but a tax agent can confirm what applies to you.
Talk to a registered tax agent once your income becomes regular, even briefly. An hour of their time upfront is cheaper than getting it wrong later.

Frequently Asked Questions

When do I have to register for GST as a fitness instructor?

Once your GST turnover reaches, or you reasonably expect it to reach, $75,000 within a rolling 12-month period. Below that threshold, registration is optional. You then have 21 days to register once the threshold is triggered.

Do I need an ABN if I also work part-time as an employee elsewhere?

You can hold an ABN for your independent training work while also being employed elsewhere on a standard PAYG basis. They’re separate arrangements. Your employed income and business income are both reported, in different ways, on your individual tax return.

How much tax should I set aside as an independent trainer?

This depends on your total income and personal circumstances, so there’s no single correct percentage: many sole traders use a rough starting estimate of 20–30% set aside from each payment, then adjust once they understand their actual marginal tax rate. A tax agent can help you set an accurate figure for your situation.

Can I claim my insurance and First Aid course as business expenses?

Costs like public liability and professional indemnity insurance, and First Aid/CPR renewal, are commonly deductible business expenses for independent fitness professionals, but eligibility depends on your specific circumstances. Confirm with a registered tax agent or accountant.

The short version

None of this needs to be intimidating. Get your ABN sorted before your first invoice, watch the $75,000 GST threshold as you grow, and set tax aside as you go. When things get more complex, a registered tax agent is worth an hour of their time.

This article is general information only and is not tax or financial advice. For guidance specific to your circumstances, consult a registered tax agent or accountant, or refer to the Australian Taxation Office at ato.gov.au.

Sources

Australian Business Register — Applying for an ABN
Australian Taxation Office — Registering for GST
Australian Taxation Office — Options for reporting and paying GST
Australian Taxation Office — Withholding if ABN not provided
Note: this article reflects the standard $75,000 GST registration threshold and general ABN process at the time of writing: always confirm current thresholds and rules directly at ato.gov.au, as tax settings can change.