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Which Documents Should My Australian Company Number (ACN) Appear On?

In Short

  • Include your Australian Company Number (ACN) and company name on all public documents, such as invoices, contracts, and official notices.

  • If your company has an Australian Business Number (ABN), and the last nine digits match your ACN, you may use the ABN in place of the ACN.

  • Failure to display your ACN on required documents can incur financial penalties of up to $1,100 per offence.

Tips for Businesses

To ensure compliance, clearly display your ACN and company name on all public-facing documents. This includes invoices, contracts, and official notices. If using an ABN instead of an ACN, ensure the last nine digits match your ACN and present it correctly. Non-compliance may lead to penalties.


Table of Contents

An ‘Australian Company Number’ (ACN) is a unique 9-digit number issued by the Australian Securities and Investments Commission (ASIC). You will receive an ACN to identify your company when you incorporate it. This article will explain the purpose of an ACN and outline key documents that the Corporations Act and regulations require your ACN and your company name to appear on.

What is An ACN?

If your company name ends in ‘Pty Ltd’ or ‘Proprietary Limited’, ‘Ltd’ or ‘Limited’, this indicates that you have registered a company. Likewise, you would have been issued an ACN upon registration. An ACN is different to an ABN (‘Australian Business Number’), as an ABN can be issued to anyone carrying out business activities, such as a sole trader. Indeed, an ACN is purely for companies.

Including your ACN and company name on certain documentation is important, as it allows other businesses and people to identify you. As many companies have similar names and subsidiaries, ACNs help to reduce fraud. Indeed, they make it possible to identify your particular company clearly.

If you decide to change your company name, you can keep the same ACN.

Which Documents Must Display My ACN?

Generally, your company’s ACN should appear on all of your:

  • ‘public documents’ (i.e. documents that are available for public use or reference); and
  • ‘eligible negotiable instruments’ (i.e. documents that promise a certain payment, such as a contract or order for service).

Your company name and ACN should appear next to each other on the first page of the document. You can display your ACN in several ways, so long as you write and display this clearly, it is easily readable, and it is obvious as to which Company it belongs. This particularly applies when you list multiple companies on a document – you must clearly display the ACN for each corresponding company.

Likewise, you may write:

  •     ‘Australian Company Number’;
  •     ‘ACN’; or
  •     ‘A.C.N.’.

For example, you could list Beds and Tables Pty Ltd ACN 123 456 789 at the top of the document.

If your company has an ABN, then you can use this number instead of the ACN provided that:

  •     the last 9 digits of your ABN are the same as your ACN; and
  •     you present the ABN in the same way that you are required to present your ACN.

Using the above example, this would read as Beds and Tables Pty Ltd ABN 12 123 456 789.

Below are some examples of common documents that require your ACN and company name.

Any Documents You Lodge With ASIC

You must include your ACN and company name on any documents that you lodge with ASIC, including: 

  •     share transfer forms;
  •     company name change forms; and
  •     forms to change the director of a company.

Invoices and Statements of Accounts

When you issue invoices, your clients need to ensure that they pay the correct company. Including your ACN allows clients to identify your company with greater certainty and reduces the likelihood of a costly mistake.

Handwritten Receipts

A handwritten receipt (or acknowledgment of payment) must contain your ACN so that the purchaser knows who they have purchased the product or service from.

Order Forms for Goods and Services

Similarly, if you are ordering goods or services for your business, the supplier should be able to identify to whom they are providing their goods or services. The added certainty of identification also assists should you want to pursue a claim against the supplier for any reason. 

Business Letterheads and Other Official Documentation

Business letterheads are considered public documents and, therefore, must contain your ACN. Although there is no legal requirement to contain other information, many businesses will voluntarily include details such as the business’:

  •     operating address;
  •     contact email address; and
  •     phone number.

This allows their clients and service providers to contact them more easily.

Official Company Notices

This includes tax returns and any disclosure notices, such as when supplier companies issue public notices about defective goods.

Cheques, Promissory Notes and Bills of Exchange

Any company that enters into a transaction should be easily identifiable.

Written Advertisements

When you publish written advertisements, beware of any legal requirements you must comply with if it falls within the definition of a ‘public document’.  

For example, in respect of an ‘official company notice’, as a general rule, an advertisement is not an official notice unless you must publish it according to:

  •     your company’s constituent documents (i.e. your company constitution); or
  •     under statute or for government purposes.

For example, under Australian corporations law, you must provide notice when advertising a proposed share buy-back.

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Use of Common Seals

Whilst less common today, a company may opt to use a common seal to execute public documents. Generally, a company’s constitution will establish the process requiring the use of a seal. However, it is not compulsory to use one. 

Companies that elect to use a common seal must include:

  • the company’s name, the expression ‘Australian Company Number’ and the company’s ACN, or
  • if the company uses its ABN instead of the ACN, the company’s name, the expression ‘Australian Business Number’ and the company’s ABN.

Which Documents Do Not Require My ACN?

Not all documents will require your ACN, and there are specific exemptions by law. For example, you do not need to print your ACN on:

  •     machine, cash-register or software generated receipts;
  •     advertisements that promote the company without making a specific offer;
  •     credit cards or vouchers;
  •     materials that are not documents (e.g. signs or television advertisements);
  •     packaging and labelling (including envelopes and transport documents); or
  •     business cards or ‘with compliments’ slips.

Non-Compliance

If you fail to have an ACN appear on required documents, financial penalties of $1,100 per offence could apply.

While the Corporations Act and associated regulations outline the basic requirements for ACN display, there are several nuanced aspects that companies should be aware of to ensure full compliance and protect their interests.

1. Contractual Implications

The inclusion of an ACN on contractual documents serves more than just an identificatory purpose. In legal disputes, the presence of a correct ACN can be crucial in establishing the exact legal entity involved in the contract. This can be particularly important in cases involving corporate groups or when dealing with businesses that operate under trading names different from their registered company names.

2. Electronic Communications

With the increasing prevalence of electronic communications in business, companies should be mindful of how ACN requirements apply in digital contexts. While the law doesn’t explicitly mandate ACN inclusion in emails, it’s generally considered best practice to include it in official email signatures, particularly for communications that could be construed as public documents or eligible negotiable instruments.

3. International Transactions

For companies engaged in international business, it’s important to note that while the ACN is a domestic identifier, including it on documents used in international transactions can still provide clarity and reduce the risk of misidentification. However, companies should also be aware of any additional identification requirements in the jurisdictions in which they operate.

4. Corporate Governance Considerations

From a corporate governance perspective, establishing clear internal policies on ACN usage can help ensure consistent compliance across all company communications. This might include:

  • standardised templates for official documents that automatically include the ACN;
  • training for staff on when and how to include the ACN; and
  • regular audits of company documents are conducted to ensure compliance.

By adhering to these additional considerations and best practices, companies can not only ensure compliance with the letter of the law but also leverage their ACN usage to enhance their legal and commercial position in various business contexts.

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Key Takeaways

Your ACN is an important identifier for your company. You must include your ACN or ABN wherever necessary so that other businesses and the public know who they are engaging for a business relationship. You may also face harsh penalties if you do not display your company name and ACN where you are required. As a general rule, you should include your company name and ACN on any public documents or negotiable instruments. 

If you need help understanding your corporate obligations or assistance registering your company, our experienced business lawyers can assist as part of our LegalVision membership. For a low monthly fee, you will have unlimited access to lawyers to answer your questions and draft and review your documents. Call us today on 1300 544 755 or visit our membership page.

Frequently Asked Questions

What is an Australian Company Number?

An ‘Australian Company Number’ (ACN) is a unique 9-digit number issued by the Australian Securities and Investments Commission (ASIC). You will receive an ACN to identify your company when you incorporate it. 

Which documents should my ACN appear on?

You should include your ACN on any documents you lodge with ASIC, invoices and statements of accounts, handwritten receipts, order forms for goods and services, and business letterheads, amongst other official documents.

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James Turner

James Turner

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