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What is a Common Seal?

In Short

  • A common seal is a company’s official stamp used to sign documents.
  • It is no longer mandatory for companies to have or use a common seal.
  • Documents signed using a common seal may still require witnessing or other formalities.

Tips for Businesses

Even though a common seal is not required, consider whether it could add value or formality to your business operations. If you choose to use one, ensure you understand the legal requirements, such as witnessing, to avoid complications with document validity.


Table of Contents

A common seal is a company signature that your company can use in certain circumstances to execute documents. Often, it takes the form of an official stamp or signature of your company. This article explains what a common seal is and how it is used to execute commercial legal documents.

What is a Common Seal?

Corporations law provides that a company may have a common seal to execute documents. A common seal (also referred to as a company seal or corporate seal) is a rubber stamp carrying the words “common seal” together with the following information:

  • the company’s name;
  • the words “Australian Company Number” (ACN); and
  • the company’s ACN; or
  • if the last nine digits of the company’s ABN are the same and in the same order as the last nine digits of its ACN, the words “Australian Business Number” and the company’s ABN.

If the company has its Australian Company Number (ACN) as its name, the common seal will only need to include the company’s ACN.

A company may also have a duplicate common seal if necessary. The duplicate common seal must be a copy of the common seal with the words “duplicate seal”, “share seal”, or “certificate seal”.

The common seal is equivalent to a person’s signature. As a result, it is important to protect it. If your company possesses a company seal, ensure that you store it in a safe and secure place.

Using a Common Seal

In most cases, companies do not need a common seal. However, if a company established its constitution before 1988 and has not updated it since then, the company must follow the rules set out in the constitution and use a common seal.

Regardless of the law, many companies choose to use a common seal. A common seal may give more legitimacy to documents, particularly from the perspective of people unfamiliar with the Australian requirements for document execution. A company with many overseas clients may execute documents with a common seal to show legality and validity.

If your company has a common seal, you must restrict its use. Using the common seal for everyday business is unnecessary, like signing off on meeting minutes. It may be appropriate to use a common seal in the following circumstances:

  • significant contracts for major purchases;
  • real property transfers and land contracts; and
  • loan documents, mortgages and guarantees.

Your company’s general counsel or legal officer should record all uses of the common seal in a register. The register should contain a record of the use of the common seal, together with a cross-reference to the board minutes authorising its use.

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How Do You Execute a Common Seal?

You must follow specific procedural requirements if your company uses its common seal. The company should ideally have a board resolution authorising the seal’s use for the specific document or transaction. The affixing of the seal itself must then be carried out by authorised persons and appropriately witnessed.

According to Section 127 of the Corporations Act 2001, typical requirements include affixing the seal in the presence of either:

  • two directors of the company;
  • a director and secretary of the company; or
  • for a proprietary company with a sole director who is also the sole company secretary.

Alternatives to Physical Common Seals

Although physical rubber stamps are an accepted method for a company’s common seal, many companies and organisations have opted for modern digital alternatives. Electronic signature solutions enable authorised parties, such as directors and secretaries, to securely apply their signatures to documents electronically.

These digital alternatives offer a secure way to create an encrypted digital imprint or image file that includes all the necessary elements of a physical common seal, such as the company name, ACN, ABN, and the phrase ‘common seal’. You can affix the digital seal file to electronic documents that require execution.

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Key Takeaways

A common seal is a rubber stamp carrying the words “common seal” and the name and business number of the business. A company does not need to have a common seal. However, if your company has one, its use requires the board of directors’ approval. As a result, it should only be used in select circumstances. In addition, you should adequately record the use of your common seal in a register.

If you need help with your company’s common seal, LegalVision’s experienced contract 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 a common seal?

A common seal (a company or corporate seal) is a rubber stamp carrying the words “common seal” with the company’s name, ACN and ABN.

When will you need a common seal?

Generally, companies with constitutions established before 1988 still require a common seal.

When is the seal not needed?

A company may execute a document without a common seal if the document is signed by two directors, a director and the company’s secretary, or if there is only one director, that director.

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Steven Tang

Steven Tang

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