How To Get An ABN In Australia: Eligibility, Costs & Registration

Getting your business off the ground in Australia usually starts with one key step: applying for an ABN.

An Australian Business Number (ABN) is more than just an ID number. It’s often what customers, suppliers and platforms will ask for before they’ll work with you, and it’s a key part of setting up your business properly (including invoicing, GST, and dealing with other businesses).

The good news is that ABN number registration can be straightforward when you know what to prepare and what to avoid. Below, we’ll walk you through how to apply for an ABN in Australia step-by-step, explain who is eligible, what it costs, and what to do after your registration for ABN is approved.

What Is An ABN (And Why Do Small Businesses Need One)?

An ABN is an 11-digit number that identifies your business (or other eligible entity) to the Australian Taxation Office (ATO) and other organisations.

If you’re running a small business, an ABN is often important because it helps you:

• Invoice customers and clients in your business name (and include your ABN on invoices)
• Avoid “no ABN withholding” where a business customer may need to withhold tax from your payment if you don’t quote an ABN
• Register for GST (if required or if you choose to)
• Set up business accounts with suppliers, wholesalers, marketplaces, and payment providers
• Build trust by showing you’re operating as a legitimate business

It’s also a foundational step when you’re deciding whether you’ll trade under your own name, register a business name, or set up a company.

If you’re still weighing up whether an ABN is right for you, it can help to understand the advantages and disadvantages of having an ABN from a small business perspective.

Who Can Get An ABN? Eligibility For Small Businesses

Before you start the registration for ABN number, it’s worth checking whether you’re eligible.

In general, you can apply for an ABN if you are:

• a sole trader (an individual operating an enterprise under your own name or a business name)
• a partnership (two or more people running an enterprise together)
• a company (a separate legal entity registered with ASIC)
• a trust
• an incorporated association or other eligible entity

What Counts As “Carrying On A Business”?

This is one of the biggest sticking points when people try to register for an ABN. The ATO generally requires that you are carrying on an enterprise (or that you have a genuine intention to start one), not just exploring an idea.

While every situation is different, “carrying on an enterprise” often involves things like:

• you have a clear intention to make a profit (even if it takes time)
• you’re advertising, quoting, or actively seeking customers
• you’ve set up tools and systems (like a website, booking system, or supplier accounts)
• you have (or are arranging) the equipment and resources you need to trade
• you’ve made business plans or started investing in the business

If you’re doing one-off work as a hobby, or you’re not really operating in a business-like way yet, you may run into problems with ABN number registration.

Do You Need An ABN As A Small Business?

Not every business must have an ABN immediately. But in practice, many small businesses apply for one early because it helps them trade smoothly and look professional.

If your customers are other businesses, they may require your ABN before they’ll pay your invoices. If you plan to operate online (including on marketplaces), you’ll often be asked for it during onboarding.

How Much Does It Cost To Get An ABN?

For most small business owners, the ATO’s ABN application is free.

So if you’re Googling “apply for an ABN cost”, the core cost is usually $0 (if you apply directly through the official government channels).

However, there can be other costs that sit around setting up your ABN and business properly, depending on how you’re starting your business, such as:

• Business name registration fees (if you want to trade under a name that isn’t your personal name)
• Company registration fees (if you’re setting up a company)
• Legal documents (like customer terms, contractor agreements, or founder documents)
• Accounting/tax advice if your structure is more complex or you need help with GST and PAYG withholding

The important point is: getting the ABN itself is usually free, but your broader business setup may involve extra steps depending on your goals and risk profile.

Step-By-Step: How To Apply For An ABN In Australia

If you’re ready to register an ABN number, here’s a practical, small business-friendly process to follow.

Step 1: Choose Your Business Structure (Before You Apply)

Your ABN is issued to an entity (like you as a sole trader, or your company), so it’s important to apply using the right structure from day one.

Common options include:

• Sole trader: simple to start and common for freelancers and early-stage businesses, but you’re personally responsible for the business’s debts and liabilities
• Partnership: used when two or more people run the business together (you’ll want clarity on roles and profit splits, often documented in a Partnership Agreement)
• Company: a separate legal entity, often chosen to manage risk and support growth (many companies adopt a Company Constitution to set out governance rules)

If you’re unsure which structure fits your business model, it’s worth getting advice early, because changing structures later can mean more admin and potential tax complexity.

Step 2: Gather The Information You’ll Need

ABN number registration is easier when you have your details ready.

Depending on your structure, you may need:

• your TFN (Tax File Number) (for individuals and some entities)
• your identity details
• business contact details (email, phone, address)
• a description of your business activities
• your business’s start date (or intended start date)
• associate details (for companies, partnerships, trusts)

If you’re setting up a company, it’s usually best to complete the company registration first, then apply for the ABN for that company (so everything lines up correctly). If you’re still forming your entity, a structured Company Set Up process can help you avoid mismatched details.

Step 3: Apply For Your ABN

Once you’re ready, you can complete your registration for ABN by applying through the appropriate government channel.

You’ll typically answer questions about:

• your structure (sole trader, company, partnership, trust)
• your business activity and industry
• who controls and benefits from the business
• whether you want to register for GST and other tax roles

Some ABN applications are processed almost instantly, while others are reviewed and can take longer (especially where the ATO needs to confirm you’re carrying on an enterprise, or have a genuine intention of doing so).

Step 4: Record Your ABN Details And Keep Them Updated

Once you get an ABN, you’ll want to store it securely and use it consistently across:

• invoices and quotes
• email signatures
• your website footer (where relevant)
• contracts and forms you give customers

You’ll also need to keep your ABN details up to date (like business address and contact details). Outdated information can cause admin delays and create confusion with customers and suppliers.

What To Do After You Get An ABN (GST, Business Names, Invoicing And Contracts)

Getting an ABN is a major milestone, but it’s usually not the last setup step for a small business.

Note: The information below is general and isn’t tax advice. GST, PAYG withholding and other tax obligations can vary depending on your situation - consider speaking with an accountant or registered tax agent if you’re unsure about what applies to you.

Should You Register For GST?

Whether you need GST depends on your turnover and business plans.

Some businesses must register for GST once they reach the turnover threshold. Others register earlier by choice (for example, to claim GST credits on business purchases).

GST can be helpful, but it also adds admin and reporting requirements. If you’re unsure, it’s worth getting tax advice so you don’t accidentally under- or over-comply.

Do You Need A Business Name?

If you trade under your own personal name as a sole trader (for example, “Jordan Lee”), you may not need a business name.

But if you want to trade under a brand (for example, “Brightside Web Studio”), you’ll likely need to register that business name. This is separate from ABN number registration.

Many small businesses handle this early through a Business Name registration step so they can start marketing confidently under their chosen brand.

Set Up Your Invoicing Properly

Once your ABN registration is approved, make sure your invoices include the basics, such as:

• your business name
• your ABN
• the date and invoice number
• a clear description of what you provided
• payment terms (when payment is due and how to pay)

Clear invoicing and payment terms reduce disputes and help protect your cash flow.

Put The Right Legal Documents In Place Early

This is the step many small businesses skip until something goes wrong. But getting your contracts and policies sorted early is often what separates a business that scales smoothly from one that keeps getting stuck in avoidable disputes.

Depending on how your business operates, you might need:

• Customer terms and conditions: sets expectations on scope, payment, refunds, timelines, and liability
• Privacy Policy: important if you collect personal information (for example, email addresses, delivery details, enquiry forms). Many businesses put a Privacy Policy in place before launching a website
• Employment Agreement: if you’re hiring staff, an Employment Contract helps set out duties, pay, leave, confidentiality and termination terms
• Shareholders Agreement: if you’re building with co-founders or bringing in investors, a Shareholders Agreement can help clarify decision-making, exits, and ownership rights

Not every business needs every document immediately, but it’s worth mapping out what applies to your operations so you’re not trying to “patch” legal gaps mid-dispute.

Common Mistakes When Getting An ABN (And How To Avoid Delays)

Most ABN applications are straightforward, but delays and refusals do happen. Here are common issues we see small businesses run into when they apply for an ABN.

1. Applying Before You’re Really Ready To Trade

If you can’t show that you’re genuinely starting or running an enterprise, your application may be delayed or refused.

It helps to have at least some of the “business-like” groundwork done (even if you haven’t made your first sale yet), such as a plan, marketing activity, supplier quotes, or basic systems.

2. Picking The Wrong Structure

If you apply as a sole trader but later realise you should have applied as a company, you can end up with extra admin and potentially messy transitions.

This is especially common where:

• two founders start informally, but they’re really operating like a partnership
• a fast-growing business needs the liability protection of a company
• an online business wants to build a brand and bring on investors later

3. Inconsistent Details Across Registrations

Your ABN details should align with your other registrations (business name, company details, banking details). Small mismatches (like using different addresses or entity names) can cause confusion when onboarding with suppliers or applying for finance.

4. Forgetting To Keep Details Up To Date

Your ABN is public-facing, and many businesses will check it before working with you.

It’s a good habit to periodically confirm your ABN is active and the details are correct. If you need to verify a supplier or customer, you can also use practical checks like how to check if an ABN is active as part of your due diligence.

5. Not Thinking About The “Bigger” Legal Setup

ABN number registration is important, but it won’t protect your brand, your pricing, your client relationships, or your internal decision-making.

That protection usually comes from having the right structure and legal documents in place, tailored to how you actually operate.

Key Takeaways

• To apply for an ABN in Australia, you’ll generally need to be carrying on (or genuinely starting) an enterprise and apply under the right structure.
• For most small businesses, the ABN application itself is free, but related setup costs can include business name registration and company registration.
• Before you register an ABN number, decide whether you’re operating as a sole trader, partnership, or company, because the ABN is issued to that entity.
• After ABN number registration, consider next steps like GST, business name registration, proper invoicing, and setting up key contracts and policies.
• Common ABN delays often come from applying too early, choosing the wrong structure, or having inconsistent details across registrations.
• Getting your legal setup right early (structure, contracts, privacy and employment documents) can save you major headaches as your business grows.

If you’d like help setting up your business properly after you get an ABN (including business structure, contracts, or key legal documents), you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no-obligations chat.