Do Australian Small Businesses Need A Common Seal Stamp?

If you run a small business, you’ve probably signed plenty of documents - from supplier agreements to leases, loan documents, and customer contracts. Every now and then, you’ll see a clause that says something like “executed under common seal” or a signature block that includes a spot for a common seal stamp.

That can be confusing, especially if you’ve never owned a stamp, never used a seal, and you’re not sure whether your company is actually required to have one.

The good news is that, for most Australian small businesses, a common seal stamp is optional. However, there are still situations where it can be useful, and there are also plenty of situations where a third party might ask for one (even if they’re not strictly entitled to).

Below, we’ll walk you through what a common seal is, whether you need one, when it’s used, how to use it correctly, and what your alternatives are if you’d prefer not to use a seal at all.

What Is A Common Seal Stamp?

A common seal (sometimes referred to as a common seal stamp or company seal) is a physical stamp or embossing device that contains your company’s details (usually the company name and ACN).

Traditionally, companies used a seal as a formal way to “execute” (sign) documents. Instead of signing by hand, a company could affix the seal to a document and have it witnessed.

These days, it’s usually:

• a rubber stamp that leaves ink on the paper; or
• an embosser that presses a raised imprint into the paper.

Important: a common seal is generally relevant to companies (Pty Ltd or Ltd). If you’re a sole trader or partnership, you wouldn’t normally use a common seal stamp.

It also helps to separate the concept of a common seal from “signatures” generally. Many documents can be validly signed without a seal, so the key question is not “what’s a common seal?” but “when do I actually need it?”

Do Australian Small Businesses Need A Common Seal Stamp?

In most cases, no - Australian companies are generally not required to have a common seal stamp.

Many small businesses choose not to use one because modern execution methods (including electronic signing) are often faster and more practical.

So Why Do People Still Talk About Common Seals?

There are a few reasons you might still come across them:

• Legacy practices: some industries and organisations have old templates that still refer to “common seal”.
• Internal governance preferences: some companies like the formality of a seal for high-value or sensitive transactions.
• Counterparty requirements: banks, landlords, government bodies, or overseas counterparties sometimes request a seal (even where it’s not strictly necessary).

What If A Contract Says I Must Use A Common Seal?

If a contract or form says the document must be executed with a common seal stamp, it’s worth pausing before you comply automatically.

Often, that wording is simply a default clause. In many situations, you can execute the document using standard company execution methods instead (more on this below), or request the other side confirm in writing they’ll accept execution without a seal.

If you’re unsure whether a particular agreement actually requires a seal (or whether a “no seal” execution could cause enforceability issues), it’s worth getting the execution block checked - especially for higher-value documents.

When Would You Use A Common Seal Stamp In Practice?

Even though it’s usually optional, there are still circumstances where a common seal stamp can be practical or expected.

Common situations include:

• Property and leasing documents: some commercial leases and deeds still include seal-based execution blocks.
• Banking and finance documents: lenders sometimes ask for execution under seal as an extra “formality” step.
• Deeds: while deeds can often be executed without a seal, many templates still assume a company will seal and witness the document.
• Overseas transactions: some overseas counterparties expect a seal because it is still common in their jurisdictions.
• Internal governance: your company may decide that certain documents (like a major asset purchase) must be sealed as part of internal policy.

One practical way to think about it is this: a common seal stamp is not usually a legal requirement - it’s a process choice. If you want it to be part of how your company signs documents, you can adopt it and set rules around its use.

Those rules often sit within your internal governance documents, like a Company Constitution, or within board or director resolutions (depending on how your company is structured).

How Do You Use A Common Seal Stamp Correctly?

If you decide to use a common seal stamp, you need to use it properly. A seal that is applied incorrectly (or without the correct witnessing) can create uncertainty about whether the company has validly executed the document.

While the exact requirements depend on the document type and the execution clause, a common approach is:

1) Check The Execution Block First

Before stamping anything, read the execution block carefully. It should tell you:

• whether the document is to be executed “under common seal”;
• how many witnesses are required; and
• who must witness (for example, two directors, or a director and a company secretary).

If the execution block is unclear, or it doesn’t match your company’s actual officer structure (for example, you have a sole director and no secretary), that’s a sign you may need to amend the execution block before signing.

2) Apply The Seal In The Correct Place

Typically, the seal is applied near the execution clause, often next to the words “common seal” or within a box provided for it.

Make sure the imprint is clear and legible. If it’s a stamp, ensure it doesn’t smudge. If it’s an embosser, ensure the paper is thick enough to show the impression.

3) Have The Right People Witness The Seal

This is the part that often gets missed. A seal generally isn’t meant to be slapped onto a document and left at that - it’s normally witnessed by the appropriate officeholders.

Under the Corporations Act, a common seal is typically witnessed by:

• two directors; or
• a director and a company secretary; or
• for a proprietary company that has a sole director who is also the sole company secretary, that sole director/secretary.

If your company has only one director (which is common for small businesses), you’ll want to be careful. Some execution blocks will not “fit” your structure unless they’re amended (for example, where the template assumes two directors will witness the seal).

Execution rules can also intersect with broader questions around signing and validity - for example, what counts as a signature, whether initials are acceptable, and whether electronic execution is permitted. If you want a deeper explanation of signing formalities, the rules around a valid signature and the legal requirements for signing documents are worth understanding.

4) Record The Use Of The Seal (Good Practice)

Even where not legally mandatory, it’s good governance to keep an internal record of when the seal is used.

Many companies maintain a “seal register” or at least store:

• a copy of the final signed document;
• the date the seal was affixed;
• who witnessed it; and
• any relevant director resolution approving the execution.

This is especially helpful later if there’s a dispute about authority, or if you need to show that the company properly approved the transaction.

What Are The Alternatives To Using A Common Seal Stamp?

If you’re thinking “this sounds like extra admin”, you’re not alone. Many small businesses prefer to execute documents without a seal.

In Australia, companies commonly execute documents without a common seal stamp by using the execution methods under the Corporations Act (for example, signing by the appropriate company officeholders).

Practically, that often means your document is signed by:

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

Many contracts also allow signing by an authorised representative, depending on how authority is granted and what the document requires. If you need someone else to sign on behalf of a director or the business (for example, when you’re travelling), you’ll want to handle that carefully - the mechanics of p.p. signatures can be useful to understand before you do it.

What About Electronic Signing?

Electronic execution is now very common, especially for everyday commercial contracts. But whether e-signing is acceptable depends on the document and the circumstances.

For example, if you’re signing a standard services agreement, an electronic signature is usually straightforward. For deeds, guarantees, and documents with strict formalities (or documents that need to be lodged/registered, such as some property-related documents), you’ll want to confirm what’s permitted and what the other side will accept. Companies can often execute documents electronically under the Corporations Act, but there can still be practical limits depending on the transaction and document type.

It also helps to remember that “signing” can happen in many ways, including via email in some cases. Whether an email can form a binding contract depends on what was said and whether there was clear offer and acceptance - this comes up often in negotiations and invoice disputes. If this is something you’re navigating, the question of whether an email is legally binding is highly relevant.

Authority-Based Signing (Instead Of Seal-Based Signing)

Some businesses prefer to avoid using a common seal stamp and instead rely on written authority processes. For example, you might issue a written delegation so a manager can sign supplier agreements up to a certain dollar value.

That’s where documents like a letter of authority can be helpful - but it needs to be drafted and used carefully, because you don’t want to accidentally create broader authority than you intended.

Common Mistakes Small Businesses Make With A Common Seal Stamp

A common seal stamp can be a useful tool, but it can also create risk if it’s treated as a “rubber stamp approval” (sometimes literally).

Here are some common mistakes we see small businesses make:

Assuming A Seal Automatically Makes A Document “More Enforceable”

A seal is a formality - it doesn’t automatically fix a poorly drafted contract, missing terms, or a deal that was never properly agreed.

If you’re unsure whether your agreement has the right elements to be enforceable (like clear scope, price, payment terms, termination rights, and liability allocation), it’s worth revisiting what makes a contract legally binding in the first place.

Using The Seal Without Proper Authority

If anyone in the business can access the seal and stamp documents, you can end up with unauthorised commitments.

To reduce risk, you should:

• store the seal securely (like a locked drawer or cabinet);
• limit who can access it;
• set internal rules about when it can be used; and
• keep a record of each use.

Not Matching The Execution Block To Your Company Structure

This is a big one for small businesses.

If you have a sole director company and the document requires two director witnesses for sealing, you may need to amend the execution block or use a different execution method.

Trying to “make it work” by getting an unrelated person to sign as if they’re a director (or leaving a signature line blank) can create serious enforceability issues.

Stamping Documents That Later Need To Be Changed

If a document is still being negotiated, avoid sealing a “nearly final” version.

If terms change after execution, you may need a formal amendment document (rather than simply marking up the signed agreement). In many cases, a Deed of Variation is the cleaner way to update an executed agreement, especially for more formal contracts.

Key Takeaways

• A common seal stamp is a physical company stamp/embosser traditionally used to execute documents, usually showing your company name and ACN.
• Most Australian small businesses do not legally need a common seal, but some choose to use one for internal governance or because counterparties request it.
• If you do use a common seal stamp, you should apply it in the correct place, ensure the right people witness it (including, for some proprietary companies, a sole director who is also the sole company secretary), and keep good records of its use.
• Many companies execute documents without a seal by using standard company signing methods, and in many cases electronic signing can also be an option (depending on the document and whether there are any extra formalities or registration requirements).
• The biggest risks are usually practical: using the seal without authority, using the wrong execution block for your structure, or sealing documents that aren’t truly final.

If you’d like help setting up (or reviewing) your company signing processes - including whether you need a common seal stamp and how to execute documents correctly - you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no-obligations chat.