Quick answer
You don’t legally need an ABN to invoice in Australia, but without one your client is required by the ATO to withhold 47% of your payment as tax (the “No ABN withholding” rule). That means on a $1,000 invoice you’d only receive $530 until you filed a tax return to claim the $470 back. Practically, every Australian freelancer, contractor, and sole trader gets an ABN before issuing their first invoice. An ABN is free, takes about 10 minutes to apply for at abr.gov.au, and is approved instantly in most cases.
Note: this is general information, not tax advice. Refer to ato.gov.au and abr.gov.au for authoritative guidance.
What “No ABN withholding” actually means
The ATO requires businesses paying for goods or services to withhold tax at the top marginal rate (currently 47%) if the supplier doesn’t quote an ABN on the invoice. The withheld amount is sent directly to the ATO. The supplier eventually claims it back as part of their tax return — but that money is locked up for months.
This rule exists to stop businesses paying off-the-books contractors who never declare the income. From the client’s perspective, the rule is not optional: if they pay you $1,000 in full without an ABN on your invoice, they can be penalised for failing to withhold.
The practical consequences for a freelancer with no ABN
- Cash flow: you receive 53% of your invoice value, not 100%. The other 47% sits with the ATO for months.
- Client reluctance: most professional clients won’t engage a non-ABN supplier at all. The extra paperwork (calculating withholding, lodging PAYG withholding to the ATO, issuing a payment summary) is rarely worth it for a small job.
- Eligibility for tools and platforms: Australian payment processors, marketplaces, and tax-deductible expense claiming systems often require an ABN.
When you genuinely don’t need an ABN
The 47% withholding rule has exceptions. You don’t need an ABN if any of these are true:
- The work is a hobby. Casual, occasional sales not run with profit intent (e.g. selling old furniture once a year on Marketplace). The ATO has guidance on hobby vs business that’s worth reading if you’re unsure.
- A one-off private transaction under $75 (excl. GST). Small, non-commercial sales below this threshold don’t trigger the rule.
- You’re an employee. PAYG employees use a Tax File Number (TFN) and their employer handles withholding through payroll. ABN is for contractors and the self-employed.
In the hobby and small-transaction cases, the supplier completes a “Statement by a supplier” form (NAT 3346, available on the ATO website) confirming the exemption. The client keeps it as evidence and pays you in full.
How to apply for an ABN (free, 10 minutes)
- Go to abr.gov.au — the Australian Business Register. This is the only official, free channel.
- Pick your entity type. For most freelancers and tradies starting out, that’s “Individual / Sole trader”.
- Provide your Tax File Number (TFN), date of birth, and contact details.
- Describe your business activity. Use plain language — “Web design”, “Plumbing services”, “Personal training”. The form maps it to an industry code automatically.
- Confirm you’re carrying on (or starting) an enterprise with profit intent.
- Submit. Most ABNs are approved instantly and the 11-digit number is shown on screen.
A small percentage of applications are held for manual review and can take up to 28 days, usually if your TFN history doesn’t match the application details. Either way, the process is free. Ignore the third-party agent sites that charge $40–$300 to do the same thing — they offer no advantage.
After you get your ABN: what changes on invoices
Add the ABN to every invoice you issue from the day you get it. The ABN typically sits right under your business name in the invoice header. For example:
Acme Web Design ABN 12 345 678 901 hello@acmeweb.com.au
Free Invoice App pre-fills your ABN once during setup and renders it on every invoice PDF automatically. If you change your business structure later (e.g. sole trader → company), you update it in one place and every new invoice picks it up.
ABN vs GST: not the same thing
A common confusion: getting an ABN doesn’t automatically register you for GST. They’re separate.
- ABN: identifies your business. Get one from day one. Free.
- GST registration: required when your turnover hits $75,000 in any 12-month period (or from day one if you drive taxis/ride-share). Below that, it’s optional.
Most new sole traders have an ABN but aren’t GST-registered. That’s the right starting point — see how to invoice without GST for the exact wording to use, and what must be on a tax invoice once you do register.
How Free Invoice App handles ABNs
Free Invoice App requires your ABN once during onboarding. From then on, every invoice you issue renders with the ABN in the header automatically. If you’re GST-registered, the invoice picks up the “Tax Invoice” wording too. If you’re not, it just says “Invoice” and skips the GST line. Get started free — once your ABN is in, you can send your first invoice in under 60 seconds.
Frequently asked questions
Can I invoice without an ABN?
Yes legally, but your client must withhold 47% of the payment as tax. You only receive 53% until you file a tax return claiming the rest. In practice, get an ABN.
How long does an ABN application take?
About 10–15 minutes online at abr.gov.au, with instant approval in most cases.
Does an ABN cost anything?
No — it’s free directly through abr.gov.au. Third-party agents who charge for it are unnecessary.
When don’t I need an ABN?
Hobby sales, one-off private transactions under $75, or PAYG employment. In those cases the supplier completes a “Statement by a supplier” to avoid the 47% withholding.
Do I need GST registration too?
Only once turnover reaches $75,000 in a 12-month period. Below that, an ABN without GST is fine.