The concept of a “substitute decision-maker” is deceptively simple but legally complex. While the role is often conflated with informal caregiving or family decision-making, in law it carries significant fiduciary duties and procedural consequences. Matters are further complicated by inconsistent terminology: the Substitute Decisions Act, the Family Law Rules, and the Rules of Civil Procedure each frame incapacity and representation in slightly different ways. For practitioners, this patchwork can create pitfalls when advising clients, drafting materials, or litigating issues involving incapable parties.
What is a Substitute Decision-Maker?
In Ontario, the concept of a substitute decision-maker is primarily governed by the Substitute Decisions Act, 1992 (the “SDA”). The SDA establishes the legal framework for individuals to appoint others to make decisions on their behalf or for the court to appoint guardians when a person is found to be incapable.
The SDA defines “incapable” as “mentally incapable” (s. 1(1)). A person is presumed capable if they are 18 years of age or more for property decisions or 16 years of age or more for personal care decisions, unless there are reasonable grounds to believe otherwise (ss. 2(1), 2(2), 2(3)).