Choosing a Substitute Decision Maker in the ACT

Choosing someone to make medical and financial decisions on your behalf is one of the hardest parts of advance care planning — harder, for most people, than drafting the Health Direction itself. The ACT gives you specific tools for this, but the default if you do nothing is a system that your family may not want.

What "Substitute Decision Maker" Means in the ACT

In the ACT, a substitute decision maker is any person who has legal authority to make decisions for someone who has lost decision-making capacity. This can be:

• An attorney appointed under an Enduring Power of Attorney (your choice)
• A guardian appointed by ACAT (the tribunal's choice)
• A Health Attorney identified by a treating clinician under the statutory hierarchy (the doctor's default)

The first option is the only one where you control who gets the role and what powers they have. The other two are fallbacks that activate when no EPoA exists — and both come with significant limitations.

How to Make the Choice

The person you appoint as your enduring attorney should be someone who understands your values and is willing to enforce them, even under family pressure. Think about these factors:

Availability — healthcare crises do not wait. Your attorney needs to be reachable by phone and able to get to a hospital or aged care facility. Appointing someone who lives in Perth or travels frequently for work creates practical delays.

Willingness to act against family consensus — if you want treatment refused and your siblings disagree, your attorney will face real pushback. Choose someone who can hold the line on what you actually want, not someone who will defer to the loudest family voice.

Understanding of your values — your attorney needs to know not just what treatments you want refused, but why. The Statement of Choices document is where you record this, but it only works if your attorney has read it and discussed it with you.

Capacity to manage financial complexity — if you are granting property and financial powers alongside healthcare, your attorney needs the organisational ability to manage accounts, pay bills, deal with Centrelink, and potentially sell property through the Access Canberra Land Titles process.

Joint, Several, or Substitute

The ACT's EPoA form gives you options for how multiple attorneys work together:

• Jointly — all attorneys must agree on every decision. This provides a check against any single person's judgment but creates problems if one attorney is unavailable or if they disagree.
• Severally — each attorney can act independently. This is faster and more practical but means one attorney can make decisions the others would not have agreed with.
• Substitute — a backup attorney who only steps in if the primary attorney is unable or unwilling to act. This is insurance against your first choice predeceasing you or becoming incapacitated themselves.

For most families, appointing one primary attorney with one substitute strikes the right balance between decisiveness and backup coverage.

What Your Attorney Cannot Do

Even a properly appointed EPoA attorney has limits. They cannot:

• Make a decision that conflicts with a Health Direction in a way section 19 of the Medical Treatment (Health Directions) Act 2006 does not permit. If the documents are inconsistent, the attorney follows the EPoA when the Health Direction was made first, and follows the Health Direction when the Health Direction was made after the EPoA.
• Request voluntary assisted dying on the principal's behalf (VAD requires the person's own active capacity throughout)
• Override a subsequent ACAT guardianship order if the tribunal has intervened
• Act in their own financial interest using the principal's assets

If ACAT appoints a guardian, that order takes priority over the EPoA for the matters it covers. This is why preventing an ACAT application in the first place — by having a clear, well-drafted EPoA — matters so much.

The ACT Advance Directive & Living Will Kit includes an attorney selection scorecard and a values conversation worksheet that gives your chosen substitute decision maker the context they need to act confidently on your behalf.

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