Knowledgebase

Guides and answers to common questions about Australian business registrations.

What is an ABN and who needs one?

An Australian Business Number (ABN) is an 11-digit number that identifies your business to the government and the community. It is issued by the Australian Business Register (ABR), which is administered by the Australian Taxation Office (ATO).

You need an ABN if you are carrying on an enterprise in Australia. This includes:

  • Sole traders running a business or providing services for payment
  • Partnerships operating a business venture together
  • Companies and corporations
  • Trusts, superannuation funds, and other entities
  • Individuals earning income from a hobby that has grown into a business activity

Without an ABN, other businesses are required by law to withhold 47% of any payment they make to you. Having an ABN also allows you to register for GST, register a business name, and claim energy grants and credits.

You do not need an ABN if you are an employee receiving a salary or wages, or if you are a hobbyist whose activities do not constitute a business. The ATO provides guidelines to help determine whether an activity is a business or a hobby, based on factors like profit intent, repetition, and commerciality.

How to register an ABN as a sole trader in Australia

A sole trader is the simplest business structure in Australia. You operate as an individual, are personally responsible for all aspects of the business, and report business income on your personal tax return.

What you need before you apply

  • Your Tax File Number (TFN)
  • Your date of birth and residential address
  • A description of your main business activity (you can use ANZSIC codes)
  • The date your business started or will start
  • Your business address (can be a home address)

The registration process

ABN applications are submitted through the Australian Business Register. Once submitted, most applications are processed immediately and an ABN is issued on the spot. In some cases, the ATO may take up to 28 days to process an application if manual review is required — this is uncommon but can happen if your identity cannot be automatically verified.

Once issued, your ABN is active immediately. You can quote it on invoices, contracts, and business correspondence straight away.

What to do after you receive your ABN

After getting your ABN, you should consider whether you need to register for GST (required if turnover will exceed $75,000), whether you need to register a business name if trading under a name other than your own, and whether you have PAYG withholding obligations if you plan to hire staff.

ABN vs ACN: what is the difference?

These two numbers are often confused, but they serve different purposes.

Australian Business Number (ABN)

An ABN is a single identifier used by all business entities — sole traders, partnerships, companies, trusts — for interactions with the ATO and other government agencies. It is used for invoicing, GST registration, and business name registration. Any business structure can have an ABN.

Australian Company Number (ACN)

An ACN is a 9-digit number assigned specifically to companies registered under the Corporations Act 2001. It is issued by ASIC when a company is incorporated. Only companies have an ACN — sole traders and partnerships do not.

When a company has both

A company registered in Australia will have both an ACN and an ABN. The ABN for a company is derived from its ACN: the ATO adds two prefix digits to the ACN to create the 11-digit ABN. For example, if a company's ACN is 123 456 789, its ABN will be XX 123 456 789.

On invoices and business documents, a company must display its ABN. The ACN must appear on all company documents including letterheads, invoices, and the company seal.

When do you need to register for GST in Australia?

Goods and Services Tax (GST) is a 10% tax applied to most goods, services, and other items sold or consumed in Australia. Registration for GST is managed by the ATO and is linked to your ABN.

Mandatory registration

You must register for GST if your business has a GST turnover (gross income minus GST) that meets or exceeds $75,000 in any 12-month period. For non-profit organisations, the threshold is $150,000. If you provide taxi or ridesharing services, you must register regardless of turnover.

Voluntary registration

You can register for GST voluntarily even if your turnover is below the threshold. This is common when your customers are other businesses (who can then claim the GST you charge as an input tax credit), or when you have significant business expenses and want to claim GST credits on those costs.

What GST registration means in practice

Once registered, you must include GST in the prices you charge, issue tax invoices for sales over $82.50, and lodge Business Activity Statements (BAS) either monthly, quarterly, or annually. You can also claim back the GST included in your business purchases.

What is PAYG withholding and do I need it?

Pay As You Go (PAYG) Withholding is a system where businesses withhold amounts from payments they make to workers and other businesses, and send those amounts to the ATO. It ensures that the recipients of those payments meet their tax obligations throughout the year rather than in one lump sum.

Who needs PAYG withholding registration

You need to register for PAYG withholding if you:

  • Have employees and pay them wages or salaries
  • Make payments to directors of a company
  • Pay contractors who do not quote an ABN
  • Make voluntary agreements to withhold tax from contractor payments

How it works

The amount withheld depends on the type of payment and the worker's circumstances. For employees, you use ATO tax withheld calculators or published tables based on their tax file number declaration. Withheld amounts are reported and paid to the ATO through your Business Activity Statement. At the end of each financial year, you provide payment summaries (or Single Touch Payroll reports) to employees and the ATO.

PAYG withholding vs PAYG instalments

PAYG withholding (for employers) is different from PAYG instalments (for individuals and businesses who pay tax in advance on their own income). PAYG instalments are managed separately and are generally set up by the ATO automatically based on your previous year's tax return.

How long does it take to get an ABN?

For most applicants, an ABN is issued immediately upon submitting the application online. The ABR's automated system verifies your identity and business details in real time, and if everything checks out, your ABN is confirmed on screen and sent to you by email within minutes.

When processing takes longer

In some cases the ATO cannot automatically verify your identity or confirm that you are entitled to an ABN, and your application is referred for manual review. This can take up to 28 days. Common reasons for manual review include:

  • Your TFN or identity details could not be matched in ATO systems
  • You have recently lodged a tax return and the records have not yet been updated
  • There are questions about whether your activity constitutes a business
  • Your application contains inconsistencies that require checking

If your application is referred for manual review, the ATO will contact you if additional information is needed.

After you receive your ABN

Your ABN is active from the date it is issued. You can look up any Australian business's ABN, trading name, and registration status at any time using the ABN Lookup tool at abn.business.gov.au.

Can I register a business name without an ABN?

No. To register a business name in Australia, you must have an ABN. ASIC, which manages the national Business Names Register, requires an ABN as part of the registration process.

What is a business name registration?

A business name (sometimes called a trading name) is a name under which you conduct business that is different from your own legal name or your company's registered name. For example, if you are a sole trader named Jane Smith but you operate under the name "Smith Consulting", you must register "Smith Consulting" as a business name with ASIC.

When you do not need a business name

You do not need to register a business name if you are a sole trader operating under your own full name (including any middle name), or if you are a company and trading solely under your company's registered name (which already includes "Pty Ltd" or "Ltd").

Business name registration vs trademarking

Registering a business name with ASIC does not give you exclusive rights to that name. It simply allows you to use the name legally for business purposes and appear in the national register. To protect your brand name nationally, you need to register it as a trademark with IP Australia. These are two separate processes.

What happens if I operate without an ABN in Australia?

Operating a business without an ABN when you are required to have one has several practical and legal consequences.

Withholding tax on your payments

The most immediate consequence is financial. If you invoice another business without quoting an ABN, they are legally required to withhold 47% of the payment and send it to the ATO. This applies even if the full amount is owed to you. To reclaim that withheld tax, you must lodge an income tax return with the ATO at the end of the financial year.

Cannot register for GST or a business name

Without an ABN you cannot register for GST, which means you cannot claim back GST on your business purchases. You also cannot register a business name with ASIC, which restricts your ability to operate under a trading name.

No access to some government programs

Certain government grants, rebates, and support programs require an active ABN as a condition of eligibility. Operating without one may exclude you from programs like the Fuel Tax Credits scheme and various state-based business grants.

What you should do

If you have been operating without an ABN and believe you are required to have one, you should register as soon as possible. The ABN application is straightforward and, for most applicants, results in an immediate outcome. Backdating of ABNs to the actual start of business activity is possible in some circumstances through the ABR.