Answers to the questions most commonly raised about Australian business registrations.
Reviewed by Naletova Advisory Pty Ltd — Registered Tax Agent No. 26027163. Last updated: 5 September 2026.
An Australian Business Number is the 11-digit number that identifies your business to government and to anyone you deal with. It comes from the Australian Business Register, which the Australian Taxation Office administers.
If you are carrying on an enterprise in Australia, you need one. That covers:
Trade without one and the law requires other businesses to withhold 47% of anything they pay you. Holding an ABN is also what lets you register for GST, register a business name, and claim energy grants and credits.
You do not need one to be an employee on wages or a salary, or to pursue a genuine hobby. Where the line falls between hobby and business is a real question, and the ATO publishes guidance on it — the tests turn on whether you intend to profit, how repeatedly you do it, and how commercially you go about it.
Sole trader is the plainest structure available here. You and the business are the same person in law, which means the responsibility is entirely yours and the business income goes on your personal return.
Applications are lodged with the Australian Business Register, and most are processed immediately with the ABN issued on submission. A minority are referred for manual review, which can take the ATO up to 28 days. This is uncommon, and generally occurs where identity details could not be verified automatically.
The ABN is active from the date of issue and may be quoted on invoices, contracts and correspondence immediately.
Whether you need GST, which is compulsory once turnover will exceed $75,000. Whether you need a registered business name, which you do if you trade under anything other than your own name. And whether PAYG withholding applies, which it will as soon as you take on staff.
These two identifiers are frequently confused, but they serve different purposes.
One identifier, used by every kind of entity — sole traders, partnerships, companies, trusts — whenever they deal with the ATO or other agencies. It is what you invoice against, what GST registration hangs off, and what a business name is registered under. Any structure can hold one.
Nine digits, issued by ASIC at the moment a company is incorporated under the Corporations Act 2001. Only companies get one. Sole traders and partnerships never do.
An Australian company holds an ACN and an ABN, and the second is built from the first: the ATO puts two digits in front of the ACN to make the 11-digit ABN. So an ACN of 123 456 789 becomes an ABN of XX 123 456 789.
Invoices and business documents must show the ABN. The ACN has to appear on company documents generally — letterheads, invoices and the company seal included.
GST is a 10% tax on most goods and services sold or consumed in Australia. The ATO manages registration, and it attaches to your ABN.
Once your GST turnover — gross income less GST — reaches $75,000 across any 12-month period, registration is compulsory. Non-profits get a higher bar at $150,000. Taxi and rideshare drivers must register from the first dollar, whatever the turnover.
Registration below the threshold is permitted and is common. It is generally worthwhile where your customers are other businesses, since they may claim the GST you charge as an input tax credit, or where your own business expenses are significant enough that claiming credits on them is advantageous.
Your prices have to include GST, sales over $82.50 need a tax invoice, and a Business Activity Statement becomes due monthly, quarterly or annually. In exchange you claim back the GST sitting inside your own business purchases.
PAYG withholding is the mechanism by which a business holds back part of what it pays workers and other businesses and forwards it to the ATO. The point is to spread the recipient’s tax across the year rather than leaving them with one bill at the end of it.
Registration is required if you:
How much you hold back depends on the kind of payment and the worker’s own circumstances. For employees you use the ATO’s withholding calculators or published tables, read against their tax file number declaration. What you withhold is reported and paid through your Business Activity Statement, and at year end the totals go to the employee and the ATO as payment summaries or Single Touch Payroll reports.
These are two different things with confusingly similar names. Withholding is what employers do to money passing through them. Instalments are what individuals and businesses pay in advance against their own income, and the ATO generally sets those up itself off the back of your last return.
For most people it is immediate. The Australian Business Register checks your identity and business details as you submit, and where everything reconciles the ABN appears on screen and lands in your inbox within minutes.
Sometimes the ATO cannot verify who you are automatically, or cannot satisfy itself that you are entitled to an ABN at all, and the application goes to a person to review. That can take up to 28 days. The usual triggers:
If it goes to manual review the ATO will come back to you directly should it need anything more.
It is active from its issue date. Any Australian business’s ABN, trading name and registration status can be checked at any time through ABN Lookup at abn.business.gov.au — including your own.
No — the ABN has to come first. ASIC runs the national Business Names Register and asks for an ABN as part of registering, so there is no way to do these in the other order.
A business name — a trading name, in older usage — is any name you trade under that is not your own legal name or your company’s registered name. A sole trader called Jane Smith who trades as "Smith Consulting" has to register "Smith Consulting" with ASIC.
There are two exceptions. A sole trader trading under their own full name, including any middle name, is not required to register. Nor is a company trading solely under its registered name, which already includes "Pty Ltd" or "Ltd".
This distinction is frequently misunderstood. An ASIC business name registration confers no exclusive right to the name; it permits lawful use of the name and records it on the national register. Securing exclusive rights requires a trade mark registration with IP Australia, which is an entirely separate process.
If you are required to hold an ABN and do not, the consequences are practical rather than theoretical.
The first one hits your bank account. Invoice another business without an ABN on the invoice and they are legally obliged to withhold 47% and send it to the ATO — regardless of the fact that the whole amount is genuinely yours. Getting it back means waiting for the end of the financial year and claiming it through your income tax return.
No ABN means no GST registration, so the GST inside everything you buy for the business stays a cost rather than a credit. It also means no business name with ASIC, so you cannot lawfully trade under anything but your own name.
A live ABN is a condition of eligibility for a range of grants, rebates and support schemes. Without one you are simply outside them — the Fuel Tax Credits scheme and most state-based business grants included.
Registration should be attended to promptly. The application is straightforward and most applicants receive an outcome immediately. In some circumstances the Australian Business Register will backdate an ABN to the date the business activity commenced, which is worth raising if you have been trading for some time.