Still Confused Between ACN and ABN? Here’s What Your Business Really Needs
Starting a business in Australia comes with its fair share of acronyms, and two of the most important ones you’ll come across are ACN and ABN.
In this guide, we’ll unpack the ACN vs ABN debate — what they mean, why they matter, and how to know which one your business needs.
What’s the difference between an ABN and an ACN?
An ABN (Australian Business Number) is a unique 11-digit number issued by the ATO. It’s used to identify your business to the government and community. Whether you’re a sole trader, partnership, trust, or company, you’ll need an ABN to register for GST, invoice clients, and operate legally.
An ACN (Australian Company Number) is a unique 9-digit number issued by ASIC. It’s only required if you’re setting up a registered company. The ACN is used to track your company’s activities, especially for compliance and reporting purposes.
In short:
- ABN = for all types of businesses
- ACN = only for registered companies
If you’re starting out and unsure which one applies, think about your business structure.
Sole trader? You’ll just need an ABN.
Registering a company? You’ll need both.
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Who needs an ACN vs ABN?
Understanding who needs an ACN vs an ABN comes down to your business structure.
Business Type | Needs ABN | Needs ACN |
Sole trader | ✅ Yes | ❌ No |
Partnership | ✅ Yes | ❌ No |
Trust | ✅ Yes | ❌ No |
Company (e.g. Pty Ltd) | ✅ Yes | ✅ Yes |
Freelancer / Contractor | ✅ Yes | ❌ No |
Not-for-profit company | ✅ Yes | ✅ Yes |
Summary:
- ABN is required for anyone running a business in Australia — whether you’re working solo, in a partnership, or operating a full company.
- ACN is only required if you’re setting up a registered company through ASIC (like a Pty Ltd). It’s part of your legal compliance and must be displayed on official documents.
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What information is included in an ACN?
An ACN (Australian Company Number) itself doesn’t contain detailed information — it’s simply a unique 9-digit identifier issued by ASIC to every registered company in Australia.
However, when you search an ACN on the ASIC register, you’ll get access to key company details, including:
- Company name
- Date of registration
- Company type (e.g. proprietary limited)
- Registered office and principal place of business
- Current status (e.g. active, deregistered)
- Names of officeholders and directors
The ACN acts like a digital fingerprint for your company. It helps ASIC and other organisations track compliance, legal status, and official records.
What information is included in an ABN?
An ABN (Australian Business Number) doesn’t embed information within the number itself — but when you look it up on the ABN Lookup register, you’ll see key business details tied to that number.
Here’s what’s typically shown:
- ABN status (e.g. active, cancelled)
- Entity name (e.g. John Smith or XYZ Pty Ltd)
- Trading name(s) (if any)
- Entity type (sole trader, partnership, company, trust, etc.)
- Date ABN was issued
- Business location (state and postcode)
- GST registration status and date
- ASIC registration (if it’s a company with an ACN)
This info helps identify the structure and legitimacy of a business. It’s especially useful for clients, suppliers, or partners doing business checks.
Summary Table of ACN vs ABN
Feature | ABN (Australian Business Number) | ACN (Australian Company Number) |
Purpose | Identifies your business to the government and public | Identifies a registered company with ASIC |
Who needs it | All business types (sole traders, partnerships, trusts, companies) | Only companies registered with ASIC (e.g. Pty Ltd) |
Issued by | Australian Taxation Office (ATO) | Australian Securities and Investments Commission (ASIC) |
Digits | 11-digit number | 9-digit number |
Used for | Invoicing, GST registration, tax purposes, domain registration | Company compliance, legal documents, ASIC tracking |
Where it appears | Invoices, business documents, websites | Company letterheads, legal documents, ASIC register |
How to find a company’s ACN?
You can find a company’s ACN by searching the ASIC (Australian Securities and Investments Commission) register. It’s a free online tool that lists all registered companies in Australia.
Here’s how:
- Go to the ASIC Connect search.
- Enter the company name or ABN.
- View the results — the ACN will be listed under the company details.
You’ll also find the ACN on official documents like invoices, business correspondence, and legal forms. By law, registered companies must include their ACN on key paperwork, so it’s usually easy to spot.
Where can I find my ABN details?
To check a business’s ABN, use the official ABN Lookup tool provided by the Australian government. It’s free, fast, and publicly accessible.
Here’s how to use it:
- Go to abr.business.gov.au
- Enter the business name, ABN, or ACN
- View details such as:
- Business name and status
- Entity type (sole trader, company, etc.)
- GST registration
- Location and start date
This tool is handy for checking if a business is active, registered for GST, or trading under another name. It helps ensure you’re dealing with a legit business — whether you’re hiring a contractor, signing a deal, or just doing your due diligence.
How to apply for an ACN vs ABN
Here’s how to apply for an ACN and an ABN, depending on your business structure.
Step | ABN (Australian Business Number) | ACN (Australian Company Number) |
Who it’s for | Sole traders, partnerships, trusts, companies | Registered companies only (e.g. Pty Ltd) |
Where to apply | Australian Business Register (ABR) | ASIC – Australian Securities and Investments Commission |
Application cost | Free | ASIC fees apply (starting from $538 for company registration) |
Time to receive | Instantly in most cases | Instantly after ASIC approves your company registration |
What you need | TFN, business structure details, business address | Company name, officeholder details, address, share structure |
Can you apply for both? | Yes – if you’re starting a company, you’ll need to apply for both | Yes – apply for ACN via ASIC first, then ABN via the ABR |
Quick tip:
- Starting a company? Apply for your ACN first through ASIC, then use it to register for your ABN through the ABR.
- Not a company? Just apply for an ABN through the ABR — no ACN needed.
Both processes are online and designed to be straightforward, especially if you have your documents ready.
Benefits of having an ABN
Having an ABN makes running your business smoother and more professional. Here’s what it unlocks:- Invoice clients properly: You can issue valid tax invoices and get paid without clients withholding tax at the top rate.
- Register for GST: If you earn $75,000 or more annually, an ABN is required to register for Goods and Services Tax.
- Claim business expenses: You can deduct eligible expenses when lodging your tax return.
- Open a business bank account: Most banks require an ABN to set one up.
Helpful guide: Best Banks for Australian Businesses - Get an Australian domain name: You’ll need an ABN to register a .com.au or .net.au domain.
- Build credibility: It shows you’re operating a legit business, which helps with trust and partnerships.
Benefits of an ACN
Having an ACN is essential if you’re registering a company in Australia. Here’s what it enables:- Limited liability protection: Your company becomes a separate legal entity, which helps protect your personal assets if something goes wrong — as long as you follow director duties.
- Builds business credibility: An ACN shows you’re officially registered with ASIC, making your company look more trustworthy to clients, investors, and suppliers.
- Required for legal compliance: All companies must have an ACN to meet ASIC requirements, file annual reviews, and keep business details up to date.
- Used on official documents: You’ll need to display your ACN on invoices, contracts, and company stationery — it’s a legal requirement.
- Enables ABN registration for companies: If you’re setting up a Pty Ltd, you’ll need an ACN before applying for your company’s ABN.
Where to display your ABN or ACN
If you’re running a business in Australia, it’s important to display your ABN or ACN in the right places, not just for professionalism, but also to meet legal requirements.
For ABN holders (sole traders, partnerships, trusts, companies):
You should include your ABN on:
- Invoices and receipts
- Quotes and estimates
- Business websites and online stores
- Purchase orders
- Business correspondence (emails, letters)
This ensures clients and the ATO can easily identify your business and reduces the risk of tax being withheld from your payments.
For ACN holders (registered companies only):
If you’re a company, you must display your ACN (or ABN if it includes the ACN) on:
- All official company documents, including invoices and receipts
- Business letterheads
- Emails and printed correspondence
- Company website (especially on the contact or about page)
- Order forms and quotes
- Any documents lodged with ASIC
Tip: If your ABN includes your ACN, you can just list the ABN — no need to show both separately.
In short:
- ABN = identify your business for tax and payments
- ACN = required for registered companies on legal and formal documents
Tax implications: ACN vs ABN
Aspect | ABN | ACN |
Tax registration | Needed to register for GST, PAYG withholding, and other tax obligations | Does not handle tax directly — ACN is for company identification |
Lodging tax returns | Used when lodging business tax returns (as a sole trader, trust, or company) | Not used for lodging tax; ACN appears on company paperwork |
Tax reporting | Essential for BAS (Business Activity Statement) and tax filings | Supports ASIC reporting, not ATO reporting |
Withholding tax | Without an ABN, clients may withhold tax at 47% from payments | Not relevant — ACN doesn’t affect withholding rules |
Business deductions | ABN holders can claim allowable business expenses | Company can claim deductions too, but tax reporting links to ABN |
GST threshold | Must register for GST if turnover exceeds $75,000/year | Applies to ABN holder; ACN companies must still register via ABN |
Key Takeaway: The ABN connects your business to the ATO for all things tax. The ACN doesn’t affect tax directly — it’s about company structure and legal compliance. If you run a company, you’ll use both, but only the ABN handles tax matters.
Can you change ABN to ACN and vice versa?
You can’t directly “convert” an ABN to an ACN or the other way around — because they serve different purposes and are issued by different government bodies.
Switching from ABN to ACN
If you’re a sole trader, partnership, or trust with an ABN and want to become a registered company, here’s what to do:
- Register a company with ASIC. You’ll get an ACN once approved.
- Apply for a new ABN for the company. This is separate from your sole trader ABN.
- Cancel your old ABN (if you’re no longer operating as a sole trader).
- Update details with banks, clients, suppliers, and the ATO.
Switching from ACN to ABN-only
If you’re closing your company and want to operate as a sole trader instead:
- Deregister your company with ASIC. This cancels your ACN.
- Apply for a new ABN as a sole trader via the ABR site.
- Update your tax and business registrations (GST, PAYG, etc.) accordingly.
Important:
- ACNs and ABNs are not interchangeable.
- You may hold both if you’re running a company.
- Changing structures affects your legal, tax, and reporting obligations — so it’s smart to get professional advice before making the switch.
Start smart; get the right setup with Sleek
Whether you’re launching a business or registering a company, Sleek makes it easy to get it right from day one. Our company registration services cover everything — from securing your ABN or ACN, to handling the admin so you don’t have to. No jargon, no delays — just fast, expert support tailored to your structure.
Got questions? Chat with our team and we’ll help you start your business the smart way.
FAQs about ACN vs ABN
Yes, the Australian Company Number (ACN) is the last 9 digits of the Australian Business Number (ABN). The ABN, which is an 11-digit number, starts with two digits, and the remaining 9 digits are the ACN.
Companies incorporated under the Commonwealth Corporations Act 2001 are assigned an ACN. If a company’s ACN is different from the last 9 digits of the company’s ABN, include the ACN in the contract.
To cancel your ABN:
- Use the same ABR portal
- Select ‘Cancel your ABN’
- Confirm your business has ceased trading
- Submit the request — cancellation is usually effective immediately
To cancel (deregister) your ACN:
You must apply to deregister your company through ASIC. You can do this if:
- All members agree
- The company has no outstanding liabilities
- Assets are worth less than $1,000
- The company is not trading
Steps:
- Complete ASIC Form 6010 online via ASIC Connect
- Pay a small deregistration fee
- ASIC will process the request and confirm the cancellation
To update your ABN details (like business address, contact info, or structure):
- Go to abr.gov.au
- Log in using your myGovID
- Select ‘Update your ABN’
- Make your changes — updates should be made within 28 days of the change
To update company details (e.g. director names, address, share structure):
- Log in to ASIC Connect
- Select your company from your dashboard
- Submit a Change to company details form
- Some changes may have a small fee or require supporting documents
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