It started over coffee in a Sydney hospital café—watching my mate argue with his siblings over Mum’s care, each waving a bundle of forms. That was when it hit me: for most Aussies, the idea of a substitute decision-maker seems distant, right until it’s painfully close. But who are these people, and what truly lies under the hood of substitute decision-making? Buckle up: this guide isn’t just about forms and legalese—it's the wild, human world of deciding for someone else.

The Core of Substitute Decision-Making: A Gritty, Human Explainer

Definition: Who Is a Substitute Decision-Maker, Really?

In Australia, a substitute decision-maker is more than just a name on a form. They’re the person legally authorised to make health and medical decisions for someone who has lost the capacity to decide for themselves. This isn’t about finances or property—this is about treatment, care, and sometimes, life-changing choices. The role kicks in only after a capacity loss trigger—like a stroke, sudden accident, or advanced dementia—renders someone unable to communicate or understand their options (Advance Care Planning Australia).

‘You’re not just signing a form—you’re stepping into someone’s shoes. That’s a huge trust.’ – Dr. Nicky Howe

Beyond the Formality: The Human Side

Imagine this: An aunt in Perth, once fiercely independent, is now in hospital after a sudden stroke. Her nephew, living in Cairns, is next of kin. The doctors need urgent decisions about treatment. The nephew remembers a conversation about her wishes, but another family member disagrees. This is where the substitute decision-maker steps in—not just as a legal tick-box, but as the voice for someone who can’t speak for themselves. It’s gritty, emotional, and often messy, especially when family opinions clash or the person’s wishes aren’t clearly documented (Healthdirect).

The Legal Nuts and Bolts: How Does Australian Law Define and Limit This Role?

Each state and territory uses its own language and rules, but the core idea is the same: a legal decision maker health is only activated when capacity is lost. For example:

• Victoria: Medical Treatment Decision Maker (Public Advocate Victoria)
• NSW/WA: Enduring Guardian
• SA/QLD/TAS/NT/ACT: Substitute Decision Maker or similar titles

Legal frameworks set out who can be appointed (usually adults with capacity, not paid carers or healthcare staff), how to appoint them, and what decisions they can make. They must always act in line with the person’s known values, wishes, and best interests (Australian Government Health).

Spot the Difference: Substitute Decision-Maker vs. Enduring Guardian vs. Medical Power of Attorney

The terms can be confusing—even for medical staff. Here’s the gist:

• Substitute Decision-Maker: Makes health/medical decisions only, after capacity is lost.
• Enduring Guardian: Appointed in NSW/WA, similar powers but may include broader personal/lifestyle decisions.
• Medical Power of Attorney: Used in some states (e.g., SA), also for health decisions, but not for finances.
• Power of Attorney/Enduring Power of Attorney: For financial/legal matters, not health.

These roles are distinct, and the right form must be completed and witnessed correctly to be valid (Australian Commission on Safety and Quality in Health Care).

Who Gets To Decide? Appointment, Hierarchies, and Family Dramas

When someone loses the ability to make their own health decisions, the question of who gets to decide can quickly become complicated—and sometimes dramatic. In Australia, the appointment of a Substitute Decision-Maker (SDM) follows a mix of paperwork, legal hierarchies, and, when families disagree, intervention by state tribunals. The process isn’t just about ticking boxes; it’s about navigating family politics, state quirks, and the very human side of planning for the unexpected.

How Are SDMs Appointed? Advance Paperwork, Hierarchies, or Tribunal

The clearest way to appoint a substitute decision maker is through formal paperwork, usually an Advance Care Directive or a state health department form. These forms are available for decision maker form download online, and must be signed and witnessed correctly. Who can witness depends on state law, but often includes doctors, lawyers, or Justices of the Peace.

If there’s no formal appointment, each state and territory has a “default list” that sets out who can decide. For example, in Queensland, the substitute decision maker QLD hierarchy starts with spouse, then adult children, parents, siblings, unpaid carers, and finally close friends. Victoria has a unique system with the medical treatment decision maker VIC role, while the Northern Territory uses the Advance Personal Plan NT. In Tasmania, guardianship panels can step in (substitute decision maker TAS).

Family Dramas and Unexpected Appointees

It’s not uncommon for families to be surprised by who’s been nominated. As Julie Phan recalls:

‘We thought she’d want her daughter to decide, but she actually nominated her neighbour! Mum always was full of surprises.’

Sometimes, the person you expect to make decisions isn’t the one chosen. This can lead to confusion, hurt feelings, or even legal challenges, especially if the paperwork isn’t clear or hasn’t been updated.

When No One Agrees: Guardian Tribunals and Conflict Resolution

Disputes over who should act as SDM are common—hundreds of cases each year end up before a guardian tribunal Australia. These state-based tribunals or boards (like VCAT in Victoria or QCAT in Queensland) can appoint an SDM, resolve conflicts, or even revoke an existing appointment. If there’s no suitable family member, the tribunal may appoint a public guardian or another trusted person.

State-by-State Quirks and Practical Steps

• Each state has its own forms and rules—always check your local health department for decision maker form download and witness requirements.
• Hospitals must verify the SDM’s authority, so keep documents handy or upload them to secure digital platforms like Evaheld or My Health Record.
• Some states allow temporary SDMs to be appointed by health practitioners if no one else qualifies.



For more on state-specific processes, visit Advance Care Directive resources or your state’s Public Advocate website.

When The Decisions Hit Hard: Rights, Responsibilities & Unexpected Grey Areas

For substitute decision-makers (SDMs) in Australia, the job is rarely black and white. The law gives clear boundaries, but the reality is a balancing act—between legal compliance, ethical responsibilities, and the unpredictable messiness of real life. As Professor Megan Howe says,

‘Being an SDM isn’t about control—it’s stewarding someone’s story when they cannot speak.’

Legal and Ethical Duties: What an SDM Must (and Can’t) Do

Every SDM is bound by strict legal and ethical responsibilities. Their core duty is to act in line with the person’s known wishes and values, not their own preferences (Advance Care Planning Australia). This means:

• Respecting advance care directives—if the person has left written instructions, these must guide every decision.
• Making decisions in the person’s best interests—where wishes aren’t clear, the SDM must weigh up what the person would have wanted, not what’s easiest or most convenient.
• Staying within legal limits—for example, refusing life-sustaining treatment is only allowed under strict rules, and outright denial of basic care (like food, water, or pain relief) is never permitted unless the law specifically allows it (Australian Government Health).

Real World Dilemmas: Risky Treatment or Holding Out Hope?

The hardest moments often come when doctors ask for a decision about risky or experimental treatments. SDMs can feel torn—should they refuse a procedure that might cause suffering, or hold out hope for a miracle? The law expects SDMs to weigh medical advice, the person’s values, and their own conscience, but never to override the person’s documented wishes (Public Advocate Victoria).

Limits on Disaster: Food, Water, Pain Relief and the Law

Australian law draws a clear line: SDMs can’t refuse basic comfort care, including food, water, and pain relief, unless a valid advance care directive says otherwise and local law permits it (Healthdirect). Even in the toughest situations, dignity and relief from suffering must come first.

Privacy Rights, Communication, and Shared Decision-Making

SDMs have the right to access private health information, but only after their authority is verified—hospitals and doctors must check documentation before sharing sensitive details (Australian Commission on Safety and Quality in Health Care). Privacy rights are tightly regulated under Australian privacy and health care acts, and digital storage platforms like Evaheld or My Health Record help keep records secure.

Importantly, SDMs are encouraged to work with clinicians in a spirit of shared decision making, not confrontation. The best outcomes come when everyone—SDMs, doctors, and families—communicate openly, respect boundaries, and keep the person’s story at the centre of every choice.

Paperwork, Pixels, and Power: How to Record and Secure SDM Details

In the world of substitute decision-making, the difference between smooth care and chaos often comes down to paperwork. Documenting decision maker details correctly is not just a formality—it’s the backbone of valid, respected choices. A missing or outdated form can leave families and health professionals scrambling, especially when time is short and emotions run high. As Dr. Saul Isaacs puts it:

‘A lost form can unravel everything. Digitise it, share it, and sleep easier.’

Why Documenting Decision Maker Details Matters

Across Australia, each state and territory has its own rules for appointing a Substitute Decision-Maker (SDM) (Advance Care Planning Australia). Whether you’re naming a Medical Treatment Decision Maker in Victoria or an Enduring Guardian in NSW, the paperwork must be completed, signed, witnessed, and stored according to local law. If it isn’t, the appointment may be invalid—leaving health teams to guess or default to a tribunal-appointed guardian.

From Shoebox to Secure Digital Record: Evaheld and My Health Record

Traditionally, families have tucked SDM forms into drawers or shoeboxes, hoping they’ll be found when needed. But as Australia’s population grows and moves, this approach is risky. Digital record decision maker solutions like Evaheld and My Health Record are changing the game. These platforms allow you to upload documents, store them securely, and share them instantly with hospitals and doctors nationwide (Healthdirect).

• Evaheld: Emerging as a secure digital storage option for advance care planning documents, offering privacy and accessibility.
• My Health Record: National platform where you can upload documents for access by authorised health professionals anywhere in Australia.

This digital approach means no more frantic searches for old appointment forms or missed emails at critical moments. As one family discovered, a missed email containing the only copy of their mother’s SDM form led to hours of confusion in the hospital—an ordeal that could have been avoided with a digital record.

Revoking or Changing Your SDM: Not Always Straightforward

Life changes, and so might your choice of SDM. Revoking or changing your substitute decision maker is ordinary, but it’s not always simple. Each state’s revocation rules differ (Victoria, national overview). You must:

1. Complete the correct revocation form or process.
2. Notify all relevant parties—family, doctors, hospitals, and anyone who had the previous details.
3. Update and upload new documents to Evaheld or My Health Record for clarity and legal certainty.



If you don’t, confusion can reign, and old decisions may be acted on in error. Digitising and sharing updates ensures everyone is on the same page, every time.

For more on documenting decision maker Australia, digital record decision maker options, secure storage Evaheld, and how to upload documents My Health Record, see Advance Care Planning Australia and Shared Decision Making resources.

Navigating The Grey: Tribunals, Conflicts, and the Substitute Decision-Maker vs. Carer Dilemma

When the moment comes to make a life-changing decision for a loved one, the question of who actually speaks for the patient can become a battleground. In Australia, the law is clear: a Substitute Decision-Maker (SDM) holds legal authority to act, trumping the role of informal carers or family members—unless a tribunal says otherwise. But in practice, the lines between SDM and carer can blur, especially when emotions run high and values clash.

Consider the hospital corridor, where a patient’s adult child (the carer) insists on one treatment, while the appointed SDM—perhaps a sibling—advocates for another. The treating team must verify SDM authority before recognising any decision, often requesting official documents or checking digital records like Evaheld or My Health Record. This step isn’t just bureaucratic: it can be the difference between timely care and dangerous delay. As advance care planning legislation and Australian guardianship laws evolve, hospitals rely on clear, accessible records to avoid confusion and ensure the patient’s wishes are honoured.

Yet, even with the paperwork in order, conflicts and disputes are common. Each year, hundreds of cases land before state and territory tribunals, such as the Victorian Civil and Administrative Tribunal (VCAT) or the NSW Guardianship Division. These tribunals exist to untangle the mess when families can’t agree, when an SDM’s authority is challenged, or when there’s evidence of conflict, incapacity, or changed wishes. As Rohan Singh, a seasoned tribunal member, puts it:

‘In eight years at the tribunal, I’ve seen families reconcile at the eleventh hour – and others fall apart over a signature.’

Tribunals can re-appoint an SDM, override decisions, or even appoint a public guardian if no suitable person is found. Sometimes, the process is triggered by a hospital’s refusal to accept an SDM’s authority, demanding further verification or clarity on the health department forms. In other cases, family members may allege that an SDM is acting against the patient’s best interests, leading to a full review of the appointment.

So, how can families and decision-makers avoid these painful disputes? The answer lies in communication, transparency, and a dash of humility. Openly discussing wishes, documenting decisions in advance, and sharing information with all involved can prevent many conflicts. And when disagreements do arise, seeking mediation or legal advice early can spare everyone a trip to the tribunal.

In the end, the role of a substitute decision-maker is both a privilege and a heavy responsibility. While the law provides a framework, the human side—empathy, honesty, and respect—remains at the heart of every decision. For more guidance, visit Shared Decision Making Australia or explore resources on advance care planning. The journey may be grey, but with the right support, it doesn’t have to be lonely.

Your healthcare wishes deserve to be clear, respected, and easy for loved ones to access when it matters most. Learn how advance care planning helps you express your treatment preferences, and explore trusted dementia care guidance for families navigating memory loss. You can document your values and personal beliefs through family legacy planning, and ensure your financial and legal affairs are secure with online will preparation tools.

When you’re ready to take the next step, explore practical nurse information resources and discover how a digital legacy vault keeps your directives accessible and safe. Find comfort in meaningful remembrance through online tribute creation, and discover meaningful and great activities for legacy preservation to keep not only your wishes, but also your story and family history — ensuring your loved ones can always stay connected to what matters most. Begin protecting your voice and your future today by exploring digital health directive solutions that give you and your family lasting peace of mind.

TL;DR: In a nutshell: Substitute decision-makers in Australia step up when someone can’t make their own health choices. These roles are shaped by state laws, personal wishes, and more than a bit of real-life messiness. Knowing how they're picked, what they can and can’t do, and how to keep those records secure (hello, Evaheld and My Health Record) sets you up for better, more respectful care decisions.