How To Set Up An ACN In Australia: Step-By-Step Guide

When you’re building a startup or growing a small business, it’s easy to get caught up in the exciting parts - product, sales, customers, funding. But if you’re planning to operate through a company structure, one of the first legal steps you’ll face is getting an Australian Company Number (ACN).

If you’ve been searching for how to set up an ACN, you’re probably trying to work out what’s required, what order to do things in, and whether you actually need an ACN at all.

The good news is: once you understand the process, setting up an ACN is straightforward. The key is making sure you choose the right structure, register correctly, and put the right documents in place so your company is ready to trade (and ready to grow) from day one.

Below, we’ll walk you through what an ACN is, when you need one, and the practical steps to set up an ACN in Australia - with the common mistakes we see startups and small businesses make along the way.

What Is An ACN (And Why Would You Need One)?

An ACN is a unique nine-digit number issued by the Australian Securities and Investments Commission (ASIC) when a company is registered in Australia. It’s basically your company’s official ID number.

It’s important to understand that an ACN is linked specifically to a company (for example, a proprietary limited company, often written as “Pty Ltd”). If you run your business as a sole trader or partnership (without forming a company), you won’t get an ACN because you’re not registering a company.

ACN vs ABN: What’s The Difference?

This is a common point of confusion for new founders. Put simply:

• ACN: issued to companies by ASIC when you register the company.
• ABN: a broader business identifier used with the Australian Taxation Office (ATO). Many entity types can have an ABN (companies, sole traders, partnerships, trusts).

Most companies will have both an ACN and an ABN. In many cases, the ABN will include your ACN within it.

When Do You Need An ACN?

You need an ACN if you want to operate as a company. That includes situations like:

• You want limited liability (so the company is responsible for its debts, rather than you personally in many situations, though there are important exceptions).
• You’re bringing in a co-founder and want clearer ownership rules and governance.
• You’re planning to raise investment (many investors prefer - or require - a company structure).
• You want the business to be able to continue independently of you (a company is a separate legal entity).

If you’re not sure whether a company is right for you, it can help to get advice early - because the “best” structure depends on your risk profile, growth plans, and tax/accounting considerations.

Before You Set Up An ACN: Decide If A Company Structure Is Right For You

Before you jump into the paperwork to set up an ACN, take a step back and confirm whether forming a company actually matches your business goals.

In Australia, the common business structures include:

• Sole trader: simplest structure, but you and the business are legally the same (meaning personal liability can be higher).
• Partnership: two or more people running a business together, usually with shared responsibilities (and potential shared liability).
• Company: a separate legal entity registered with ASIC (this is when you’ll need an ACN).
• Trust: commonly used for asset protection and certain tax planning strategies (often alongside a corporate trustee).

Many startups and small businesses choose a proprietary limited company because it can help manage risk and makes it easier to bring on shareholders later. If you’re heading down that path, you’ll typically also need a Company Constitution (or you may rely on replaceable rules, depending on your setup).

A Quick Note On “Pty Ltd”

If you see businesses with “Pty Ltd” at the end of their name, that’s a proprietary limited company. This is one of the most common structures for Australian startups and small businesses because it’s designed for privately owned companies (as opposed to public companies).

How To Set Up ACN In Australia: Step-By-Step

Now to the practical part: how you actually set up an ACN.

In Australia, you get an ACN by registering a company with ASIC. Once ASIC registers the company, they issue the ACN.

Step 1: Choose Your Company Name

You have a couple of options when naming your company:

• Use your ACN as the name (for example: “123 456 789 Pty Ltd”).
• Register a company name (for example: “Your Startup Pty Ltd”).

If you want a specific company name, it needs to be available and comply with ASIC’s rules (including restrictions around certain words). Also, a company name is not the same thing as a business name or a trade mark - they serve different purposes.

From a branding perspective, you may also want to think early about protecting your name. For example, registering your business name doesn’t automatically protect it as intellectual property.

Step 2: Decide Who The Directors And Shareholders Will Be

When you set up a company, you’ll need to decide:

• Directors: the people responsible for managing the company and meeting legal duties.
• Shareholders: the owners of the company (they hold shares).

In a small business or early-stage startup, directors and shareholders are often the same people - but not always, especially once investors come in.

If you’re starting with co-founders, it’s worth getting clear on ownership and decision-making early. A Shareholders Agreement can help set expectations about things like:

• who owns what percentage of the company
• how big decisions are made
• what happens if someone wants to leave
• how disputes are managed

Step 3: Decide Your Share Structure

ASIC will require details about how the company will be owned. You’ll need to decide things like:

• how many shares will be issued
• who they will be issued to
• the class of shares (if you’re using different share classes)
• the amount paid (or payable) for shares

This step matters more than many founders realise. Your share structure can affect everything from future fundraising to founder exits, so it’s a good idea to get it right from the start.

Step 4: Choose Your Registered Office And Principal Place Of Business

ASIC requires a registered office address (this is the official address for the company). You may also need to provide your principal place of business.

If you’re using an address you don’t own (for example, an accountant’s office, a coworking space, or someone else’s premises), you may need written consent to use that address.

Step 5: Register The Company With ASIC (This Is Where You Get Your ACN)

This is the step where you officially get your ACN - because your ACN is issued as part of the company registration process.

Once the company registration is processed, ASIC will issue:

• your ACN
• a certificate of registration

At this point, your company legally exists and can enter into contracts (provided it is acting through the correct signatories).

Step 6: Apply For An ABN, TFN, GST And PAYG (If Needed)

After you’ve set up your ACN and your company is registered, you’ll usually apply for:

• ABN (commonly needed to invoice customers and deal with other businesses)
• Tax File Number (TFN) for the company
• GST registration (required if your turnover is $75,000+ per year, and optional in some other cases)
• PAYG withholding if you will employ staff

This part is not technically setting up an ACN, but it’s the practical follow-on work that makes your company ready to trade compliantly.

Note: The ABN/TFN/GST/PAYG information above is general only and isn’t tax advice. Your tax registrations and obligations can vary depending on your circumstances, so consider speaking with an accountant or registered tax agent.

Step 7: Set Up Your Governance And Key Company Documents

Getting an ACN is only one part of setting up a company properly. To avoid messy disputes later, your company should be supported by clear documentation.

Depending on your setup, you may need:

• Company Constitution to set rules for how the company is governed (many growing businesses adopt a Company Constitution tailored to their needs).
• Shareholders Agreement to clarify decision-making and ownership arrangements between co-owners (a Shareholders Agreement is particularly useful if you have two or more shareholders).
• Employment contracts if you’re hiring employees, so expectations about duties, pay and termination are clear (an Employment Contract is a common starting point).
• Privacy documents if you collect personal information (which many businesses do via websites, email lists and payment systems) - a Privacy Policy is often essential.

These documents help your business run smoothly and reduce legal risk as you scale.

Common Mistakes When Setting Up An ACN (And How To Avoid Them)

Most founders don’t struggle with the application itself - they struggle with the decisions around it. Here are some common issues we see when people try to set up an ACN quickly without thinking through the bigger picture.

Registering The Company But Not Locking Down Founder Arrangements

It’s common for co-founders to rush into registration, split shares informally, and “sort the details later”. The problem is that later often arrives when there’s pressure - money, customers, deadlines, and stress.

If you’re starting with others, it’s usually better to agree early on things like roles, equity, decision-making and exits, and then document it in a Shareholders Agreement.

Using A Name Without Checking Branding And IP Risks

ASIC approving a company name doesn’t mean you’re free to trade with that name without issues. Another business may already be using a similar brand, or may own a trade mark that creates a risk for you.

This is especially important if you’re planning to invest in marketing, packaging, signage, or a website domain.

Forgetting Ongoing Company Obligations

A company structure comes with ongoing responsibilities. For example, ASIC records need to be kept up-to-date, and there are director duties that apply once you’re running a company.

That doesn’t mean you should avoid setting up an ACN - it just means you should go in with your eyes open and set up good systems early.

Not Setting Up Customer-Facing Terms Early

Even at the startup stage, you’re likely entering into agreements with customers - whether that’s through proposals, invoices, online checkout pages, or platform subscriptions.

Clear terms can help prevent disputes around payment, delivery, timelines, refunds, and liability. Depending on how you operate, this might be through formal service agreements or terms and conditions.

What Other Legal Areas Should Startups And Small Businesses Think About After They Set Up An ACN?

Once you set up an ACN and your company is ready to trade, the next step is making sure the way you operate is legally compliant. This will look slightly different depending on whether you’re selling products, providing services, operating online, or hiring staff, but there are a few key areas that apply to most businesses.

Australian Consumer Law (ACL)

If you sell goods or services to customers in Australia, you’ll need to comply with the Australian Consumer Law (ACL). This affects how you advertise, what you promise customers, and how you handle refunds and complaints.

It’s also relevant to how you write your customer terms, because you generally can’t contract out of certain consumer guarantees.

Privacy And Data Protection

If your business collects personal information (names, emails, phone numbers, delivery addresses, payment information, IP addresses), you’ll likely need privacy compliance measures in place.

In many cases, having a clear Privacy Policy is a practical starting point, particularly if you’re operating online.

Employment And Contractor Arrangements

Hiring your first team member is a big milestone - but it also creates legal obligations. Misunderstandings about pay, duties, notice, and termination can become costly quickly.

For employees, an Employment Contract can help set expectations clearly. If you’re engaging contractors, you’ll want the correct contract structure to reflect the relationship and protect your business.

Signing Contracts Correctly

As your company starts signing customer agreements, leases, supplier arrangements, or investor documents, it’s important to make sure they’re signed correctly in the company’s name.

Companies can sign in different ways (including under the Corporations Act), and signing incorrectly can cause delays or disputes about whether an agreement is binding.

Key Takeaways

• To set up an ACN in Australia, you need to register a company with ASIC - your ACN is issued as part of that registration.
• Before registering, it’s worth confirming whether a company structure fits your goals, risk profile, and growth plans (compared with being a sole trader or partnership).
• Setting up an ACN is only one piece of the puzzle - a strong foundation often includes a Company Constitution and, where relevant, a Shareholders Agreement.
• After company registration, many businesses also need an ABN and may need GST and PAYG registrations depending on turnover and staffing plans (this is general information only and isn’t tax advice).
• Legal compliance doesn’t stop once you get an ACN - Australian Consumer Law (ACL), privacy, and employment obligations can all apply early, especially as you start trading.
• Clear contracts and policies (including an Employment Contract and Privacy Policy) can help prevent disputes and support sustainable growth.

If you’d like help setting up your company and ACN (and getting the documents and legal foundations right from the start), you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no-obligations chat.