Receive Our Best Content Straight to Your Inbox
Thinking of starting a company in Australia? You’ll need more than just a business idea; you’ll need an ACN.
While ABNs and TFNs get most of the attention, the Australian Company Number (ACN) is essential if you’re setting up a registered company. It’s a legal requirement that helps identify your business and keep you compliant with ASIC.
In this guide, we’ll break down exactly what an ACN is, why it matters, and how to get one without the jargon.
What is an ACN?
An ACN (Australian Company Number) is a unique nine-digit number issued to every company registered in Australia. It’s assigned by ASIC; the government body that regulates companies and financial services, and acts as your business’s official ID under Australian law.
Your ACN stays with your company for life. It’s used to identify your business in ASIC records, legal documents, and public registers, helping distinguish it from every other company in the country. In short, if you’re setting up a company, having an ACN isn’t optional, it’s essential.
Contact Sleek now!
Why does an ACN matter?
An ACN isn’t just another number, it’s the legal identity of your company in Australia. If you’re running a registered company, your ACN is what keeps everything above board with ASIC, your clients, and the law.
Here’s why it matters and how it benefits your business:
- It proves your company exists
Your ACN is a unique nine-digit ID that confirms your business is registered and compliant under the Corporations Act 2001. - It’s required on official documents
Invoices, contracts, letterheads, and ASIC filings must display your ACN. It adds legitimacy and helps stakeholders verify your business. - It protects your business identity
The ACN distinguishes your company from others, especially important if you have a similar business name to someone else.
- It supports transparency and trust
Having an ACN shows you’re serious and operating under a formal structure. That goes a long way with banks, clients, suppliers, and investors. - It helps with regulatory compliance
Your ACN is how ASIC tracks your company’s filings, financial records, and governance activity, it’s essential for staying on the right side of regulation.
In short, if you’re registering a company in Australia, getting an ACN is non-negotiable, and for good reason. It’s your company’s official footprint in the system.
Do you need an ACN? The company structure question
Not every business in Australia needs an ACN, it depends on your structure.
If you’re setting up a company, like a proprietary limited (Pty Ltd), you must register with ASIC. Once approved, you’ll be issued an ACN as part of the company setup, it’s a legal requirement for this structure.
But if you’re a sole trader, in a partnership, or operating under a trust, you generally don’t need an ACN. In those cases, an Australian Business Number (ABN) is usually all that’s required. Just make sure you understand which structure suits your business best, it affects how you register and what compliance looks like from day one.
How to Get an ACN
You don’t apply for an ACN separately, it’s automatically issued when you register a company with ASIC. The key is getting the company setup process right from the start.
Here’s what you’ll need to do:
- Choose your company structure
Most businesses go with a proprietary limited (Pty Ltd) structure, but make sure it suits your goals and compliance needs. - Pick a compliant company name
Your name must meet ASIC’s naming rules and be available. You can check availability through the ASIC register before lodging your application. - Get consent from directors and secretaries
You need at least one Australian-resident director. All appointees must give formal consent to their roles. - Identify shareholders and issue shares
Decide who owns the company and how many shares each person will hold. - Nominate a registered office address
This must be a physical address in Australia, PO boxes aren’t accepted.
Check out our article to understand why you might need two business addresses – A principal place of business and a registered business address.
- Decide on governance rules
You can either adopt a company constitution or use ASIC’s replaceable rules under the Corporations Act. - Submit Form 201 and pay the fee
Lodge your company registration through ASIC’s online portal.
If everything checks out, ASIC will issue your Certificate of Registration, which includes your new Australian Company Number (ACN), your company’s official ID.
How can Sleek help with the ACN application process
Not sure where to start with registering your company or managing your ACN obligations? Sleek makes it simple. We handle the entire company setup process and help you stay compliant with ASIC, without the admin stress.
Here’s what we can do for you:
- Register your company and secure your ACN through ASIC
- Set up your ABN, business name, and GST registration
- Ensure your company name meets ASIC’s requirements
- Keep your company records up to date (directors, shareholders, addresses)
- Lodge ASIC updates and annual statements on time
- Provide ongoing compliance support so you stay legally covered
Whether you’re just starting out or already running a company, we’ll help you stay on track.
What happens after you get your ACN?
Getting your ACN is just the beginning. Once your company is registered, you take on ongoing responsibilities, and staying compliant with ASIC is a big one.
You’re required to keep your company details up to date. That includes notifying ASIC of any key changes, such as:
- Company directors or secretaries (including your resident director)
- Registered office or principal place of business
- Shareholder details
You typically have 28 days to report these changes, miss the deadline and you could face late fees or compliance issues.
Each year, ASIC will send you an annual statement around your registration anniversary. You’ll need to:
- Review and confirm your company details
- Make any necessary updates
- Pay the annual review fee to keep your registration active
Running a company means staying on top of these admin tasks, but with the right support and systems, it doesn’t have to be hard.
Using Your ACN
Your ACN is your company’s official ID, and you’ll use it often. It’s required when dealing with government bodies like ASIC and the ATO, and acts as proof that your business is registered as a separate legal entity.
Banks will ask for your ACN when opening a business bank account, and suppliers or lenders may request it for onboarding or credit checks. It helps them verify your company’s registration status through the ASIC register.
You’ll also need to include your ACN on contracts, invoices, legal documents, and official communications. It confirms you’re operating as a legitimate company under Australian law and keeps things running smoothly with clients, regulators, and partners.
ACN search: Finding company information
Since an ACN is a public identifier, anyone can use it to look up details about a registered company in Australia. ASIC provides a searchable business register where you can search by company name or ACN.
The ASIC register shows key information like a company’s registration status, start date, office addresses, and names of current or past directors. It’s a quick way to confirm a company is legit and still active.
This tool is especially useful for doing due diligence. Whether you’re vetting a supplier, client, or business partner, running a quick ACN search helps you stay compliant and reduce risk. You can access the search directly through ASIC’s website.
Check our guide – How to obtain an ASIC Company Extract
Conclusion
Your ACN is more than just a number, it’s your company’s legal identity in Australia. Issued by ASIC to registered companies only, it confirms you’re operating as a separate legal entity under the law.
It’s not the same as an ABN, which is used for tax purposes like GST. Only companies receive an ACN through the registration process; sole traders and partnerships don’t.
Using your ACN correctly on official documents helps you stay compliant from day one. Keeping your company details up to date with ASIC also ensures your registration remains in good standing. If you’re a director or business owner, knowing how your ACN works is essential to running a compliant and credible company.
Frequently asked questions about ACNs
No, sole traders don’t get an ACN. ACNs are only issued to registered companies under the Corporations Act 2001. As a sole trader, you operate as an individual using an ABN for business and tax purposes.
There’s no legal separation between you and the business, you’re one and the same. If you decide to incorporate later, you’ll need to register a company with ASIC. That new company would receive its own ACN, but the individual never gets one directly.
No, your company’s ACN is permanent. Once it’s issued by ASIC during registration, it stays with your company for life.
Even if you update the company name, change directors or shareholders, or shift your business activities, the ACN doesn’t change. It’s the fixed identifier that connects all your records on the ASIC register, and that consistency is key for tracking your company’s legal and compliance history.
No, your ACN doesn’t expire. It stays valid for as long as your company remains registered with ASIC.
If your company is deregistered whether voluntarily or by ASIC for non-compliance; the ACN becomes inactive for trading. But it still stays on the record as part of your company’s history. It’s a permanent ID, even after the business closes.
Misplaced your ACN? No stress, it’s easy to track down. You’ll find it on key documents like your Certificate of Registration or past annual statements from ASIC.
If you don’t have those on hand, just run a quick search on the ASIC register using your company name. It’ll bring up your public record, including your ACN, registration status, and other key details.
incorporation, accounting, tax
services, and compliance.
450,000
businesses worldwide.
from 4,100+ reviews.
satisfaction rate from
16,000 surveyed clients.
450,000
businesses worldwide.
from 4,100+ reviews.
satisfaction rate from
16,000 surveyed clients.
