Is It Legal to Sign on Someone Else’s Behalf? (2026 Update)

Signing on behalf of someone else is legal in Australia when you have that person’s authority to do it. That authority comes from written permission, a power of attorney, or a role that already carries the right to sign. Sign without it and you’ve committed forgery, a criminal offence that carries up to 10 years in prison.

Here’s the moment almost everyone has faced. Your boss is stuck in a meeting, a document needs signing now, and someone says “just sign it for them.” You freeze. You’re not sure if that’s allowed, or if you’re about to do something you’ll regret. That hesitation is the right instinct. The rules are simpler than they feel, and this guide walks you through every one of them.

When is it legal to sign on behalf of someone else?

It’s legal the moment you have the other person’s authority, and not a second before. Everything else in this article is detail hanging off that one rule. The question is never really “can I sign for them?” It’s “can I prove they let me?”

Authority shows up in a few forms. Someone can give you written permission for a specific task. They can appoint you under a power of attorney. Or your role can carry the authority built in, like a company director signing for the company. Each one works. What they share is a record that points back to the person who actually owns the decision.

A trap worth naming early: people lean on verbal permission and assume it’ll hold up. It might. But if the document ever gets questioned, “they said I could” is a weak position when the other person has changed their mind or can’t remember the chat. A two-line text or email saying “yes, sign the supplier letter for me” turns a he-said-she-said into proof. Get it before you sign, not after.

When does signing on someone else’s behalf become illegal?

Permission is the line. Sign a document in someone’s name without their authority, and you’ve forged it. Forgery is a criminal offence in every Australian state and territory, and the maximum penalties are serious. Under the Crimes Act 1900 (NSW), falsifying a document can carry up to 10 years in prison, and the other states have their own equivalents. Forge a Commonwealth document, like a tax form, and the Commonwealth Criminal Code applies instead, with the same 10-year ceiling.

The legal test turns on intention to defraud. That sounds dramatic, but it catches more everyday situations than people expect. If you sign in someone’s name to gain something, and they didn’t authorise it, the intent is there even if you told yourself you were helping. Here’s the part that surprises people most: you can still be on the wrong side of it when you genuinely believed you had permission. Belief isn’t authority. Proof is.

So the safe habit is boring and effective. Before you put a pen near someone else’s name, confirm they’ve actually asked you to, and keep something in writing that shows it. That single step is the difference between doing someone a favour and committing a crime.

How to sign on behalf of someone else (with examples)

Once you have authority, there are two clean ways to sign on behalf of someone else. The right one depends on how serious the document is. Most people overthink this. For a letter, you need almost nothing. For a binding contract, you need a power of attorney or proper delegated authority.

Method 1: using “p.p.” (per procurationem)

“p.p.” is short for per procurationem, Latin for “through the agency of.” You write it before your own signature to tell the reader, plainly, that you’re signing for someone else with their say-so. Underneath, you put the name and title of the person you’re signing for. That’s it.

It suits letters, internal forms and correspondence. It is not the tool for anything legally binding, like a loan, a lease or a contract for the sale of property. Use it where a signature confirms a message, not where it locks someone into an obligation. Here’s how it looks on a letter:

Yours sincerely,

p.p. Jordan Tran
[your signature]

Sam Rivera
Managing Director

That signal is doing the work here. Anyone reading it can see Jordan signed, on Sam’s behalf, with permission. If you’d rather spell it out in plain English, “for and on behalf of” does the same job and reads more clearly to people who’ve never met the abbreviation.

Method 2: using a power of attorney

A power of attorney is the heavyweight option. It’s a legal document where one person (the principal) gives another (the attorney) authority to sign and act for them. It’s what you reach for when the person is travelling, has lost capacity, or simply wants someone trusted to handle their affairs. With a valid power of attorney in place, you can sign documents that actually bind the principal, not just letters.

Two things trip people up. First, the rules differ by state, so a power of attorney set up in Victoria isn’t a carbon copy of one in Queensland. Second, a general power of attorney ends the moment the principal loses mental capacity, which is exactly when families assume it kicks in. If you want the authority to survive incapacity, you need an enduring power of attorney. Getting that distinction wrong is one of the more common and costly mistakes we see.

When you sign under a power of attorney, make the authority visible in the signature block so the reader knows where it comes from:

Signed by Jordan Tran
as attorney for Sam Rivera
under power of attorney dated 14 March 2026

[your signature]
Date: ___ / ___ / ______

If you’re working out who should hold the role and how to set it up, our guide on how to appoint a power of attorney walks through it step by step.

Who can sign on behalf of a company?

Signing for a company is a different beast, and it’s where small business owners slip up most. A company is its own legal person, so it can’t hold a pen. Someone has to sign for it, and the law sets out who and how. Get it wrong and the contract can be unenforceable.

Your cleanest route is section 127 of the Corporations Act 2001 (Cth). A company validly signs when the document is signed by two directors, a director and the company secretary, or, for a proprietary company, a sole director who is also the sole secretary (or a sole director where the company has no secretary at all). When a document is signed this way, the other side is entitled to assume it was properly executed. That assumption is the whole point. It’s what lets people trust a company’s signature without auditing its internal paperwork.

What about an employee who isn’t a director? They can sign too, but only with delegated authority behind them, and the signature block needs to show they’re signing for the company in a representative capacity. A section 127 block looks like this:

Executed by Brightline Pty Ltd (ACN 123 456 789)
in accordance with section 127 of the
Corporations Act 2001 (Cth):

_____________________      _____________________
Director                   Director / Secretary

Name:                      Name:
Date:                      Date:

Two updates worth knowing, because plenty of older articles still get them wrong. Since February 2022, companies can sign documents electronically and by “split execution,” meaning two officers don’t have to sign the same physical page. The same reforms let an agent execute a deed for a company without the deed itself being witnessed. If your company still has a common seal, that’s another valid way to execute, though far fewer companies bother with one now. And yes, companies can sign documents electronically as a permanent fixture, not a pandemic stopgap.

Can you sign electronically on someone else’s behalf?

Yes, and an eSignature carries the same legal weight as a wet-ink one for most documents. The rules haven’t changed because the ink went digital. You still need the person’s authority to use their signature, whether that’s an image of it, their typed name, or access to their eSignature account.

Electronic signing has quietly cut down how often anyone signs for someone else at all. When the principal can sign from their phone in 20 seconds, there’s less reason to hand the job to a colleague. But the moment you do use someone’s eSignature for them, the rule snaps back into place: you need written authority to do it, and you’ll want a record of that authority sitting alongside the signed document. Same principle, new medium.

Documents you should never sign for someone else

Some documents are personal in the eyes of the law, and no amount of permission lets you sign them for another person. This is the part most articles skip, and it’s the part that gets people into real trouble.

• Wills. A will has to be signed by the person making it, in front of witnesses. Holding a power of attorney does not let you write or sign someone’s will for them.
• Statutory declarations and affidavits. These are sworn statements of personal truth. Only the person swearing them can sign, in front of an authorised witness.
• Voting papers. Your vote is yours. Signing or casting it for someone else isn’t a favour, it’s an offence.
• Marriage and similar personal-status documents. Consent has to come from the person directly.

The pattern to remember: the more a document depends on the personal intention or honesty of the signer, the less anyone else can stand in. When in doubt, treat the document as off-limits and check before you sign.

State-by-state: witnessing and electronic signing

For ordinary contracts, a plain signature is enough across Australia, and you can sign electronically anywhere. Deeds are stricter, and that’s where the state you’re in starts to matter. A deed usually needs a witness, except in two states that have dropped the requirement for individuals. Here’s the quick version:

State / territory	Witness needed for a deed (individual)?	Can an individual sign a deed electronically?
NSW	Yes	Yes (witnessing can be done electronically)
VIC	No	Yes
QLD	No	Yes
WA, SA, TAS, ACT, NT	Yes	Limited: print, sign in front of a witness, then scan

Here’s what that table is telling you. If you’re signing a deed for someone in WA, SA, TAS, the ACT or the NT, don’t assume you can do it all on screen, because you may still need wet ink and a physical witness. And companies sit outside this grid entirely: a company executing a deed under section 127 doesn’t need a witness at all, anywhere in the country.

What we see in Lawpath consultations

The signing question rarely arrives on its own. It shows up buried inside a bigger decision, and across consultations our lawyers see the same few patterns trip founders up.

Founders document deals informally, then can’t rely on them. A common scene: a founder gets an important agreement signed at the kitchen table and witnessed by a family member, or signs it themselves without checking whether the company needed to execute it under section 127. It feels done. Months later, when an investor or buyer reviews the paperwork, the execution gets questioned and the deal stalls. The fix costs far more than doing it properly the first time.

People assume incorporating doesn’t change how they sign. Sole traders sign in their own name, and that’s correct, the business and the person are the same thing. The week they become a company, that stops being true. We regularly speak with new directors still signing “as themselves” on company contracts, leaving it unclear whether the person or the company is actually bound. Once you’re a company, you sign as a director, for and on behalf of the company.

Verbal authority feels like enough until it isn’t. The pattern we see again and again is someone signing on a quick “yeah, that’s fine” and only later wishing they had it in writing. Nobody plans for the relationship to sour or the memory to fade. A 10-second text at the time prevents almost every version of this problem.

A quick checklist before you sign for someone

Run through these five questions before you sign on behalf of someone else. It takes a minute and saves a lot of grief.

1. Do I actually have permission? Not “I think so.” A clear yes from the person, for this document.
2. Is that permission in writing? A text or email is plenty for everyday documents. For anything binding, you want a power of attorney or written delegated authority.
3. What kind of document is this? A letter takes “p.p.” A contract or deed needs real authority. A will, stat dec or vote can’t be signed by anyone but the person.
4. Am I signing for a person or a company? If it’s a company, follow section 127 and use a representative-capacity signature block.
5. Have I read the whole thing? You’re putting your name to it. Read it, and ask about anything you don’t understand before you sign.

Common mistakes when signing on behalf of someone

A few errors come up over and over. Each one is easy to avoid once you’ve seen it.

• Relying on verbal permission. It might be true, but it’s hard to prove. Get a line in writing.
• Hiding the fact you signed for someone. Signing the person’s name as if you were them, with no “p.p.” or representative wording, reads as forgery even when you had permission. Always make the capacity clear.
• Using “p.p.” on a binding contract. It’s built for letters, not for documents that create real obligations. Use a power of attorney instead.
• Assuming a general power of attorney survives incapacity. It doesn’t. You need an enduring power of attorney for that.
• Signing a company document as yourself. If the company is the party, sign as a director for and on behalf of the company, not in your personal name.

Frequently asked questions

Is it illegal to sign someone’s name without their permission?

Yes. Signing someone’s name without their authority is forgery, a criminal offence in every Australian state and territory with maximum penalties around 10 years in prison. It applies even if you believed you had permission. Always get a clear yes, ideally in writing, before you sign.

What does “p.p.” mean when signing?

“p.p.” stands for per procurationem, Latin for “through the agency of.” You write it before your signature to show you’re signing on behalf of someone else with their authority. It suits letters and informal documents, not binding contracts.

How do I sign for someone with their permission?

For a letter, write “p.p.” then your signature, with the other person’s name and title underneath. For anything binding, sign under a power of attorney and state that in the signature block. Either way, keep written proof of the permission.

Can I sign a contract on behalf of my company?

Yes, if you’re authorised. The clean route is section 127 of the Corporations Act: two directors, a director and secretary, or a sole director who is also sole secretary. Employees can sign with delegated authority. Use a signature block showing you sign for the company.

Can I sign a document for my spouse or parent?

Only with their authority, and never for personal documents like wills, statutory declarations or votes. For everyday paperwork, written permission is enough. For binding documents, or if they’ve lost capacity, you need an enduring power of attorney.

Is an electronic signature valid when signing for someone?

Yes. An eSignature carries the same legal weight as a wet-ink one for most documents. You still need the person’s written authority to use their signature, and you should keep a record of that authority with the signed document.

What happens if I sign without authority?

Two things can go wrong. The document may be void or unenforceable, and you may have committed forgery if there was intent to gain something. The person whose name you used can also pursue you. The risk drops to almost nothing once you have written authority.

Do I need a power of attorney, or is written permission enough?

It depends on the document. A text or email covers letters and low-stakes forms. A power of attorney is for binding documents, ongoing authority, or situations where the person can’t sign themselves. When the stakes are high, choose the power of attorney.

Before you sign, take a breath

If you’re holding a pen over someone else’s name and feeling unsure, you’re already doing the right thing. Most people get this wrong by rushing, not by bad intent. Confirm you have permission, get it in writing, match the method to the document, and you’re on solid ground.

When the document actually matters, set up the authority properly from the start. You can create a power of attorney in minutes, or get a fixed-fee quote from a small business lawyer to check you’re signing the right way before anything is binding. Sort it once, and you never have to second-guess the next signature.