Do you have Capacity to Sign your Will?

We tend to think of a will as the clearest expression of a person’s final wishes: a document that speaks with certainty after someone is gone. But the law asks a deeper question before accepting those wishes: was the person actually capable of making them?

This idea is known as testamentary capacity, and it sits at the heart of many estate disputes. It’s not about whether a will is fair, kind, or even rational in the eyes of others. Instead, it’s about whether the person who made it understood what they were doing at the time.

To have capacity, the testator must understand a few important elements. They need to

understand that they are making a will and the effects of their will. They should have a general sense of their assets, who might expect to benefit from their estate, and how their decisions affect those people, including the nature of any claims made by a person excluded under the will. In short, they must be able to connect their choices to real-world consequences.

What’s often misunderstood is what does not automatically destroy capacity. Poor physical or mental health does not, on its own, invalidate a will. A person can be depressed, taking

medication, or living with significant illness and still meet the legal threshold. Courts have

repeatedly emphasized that capacity is about cognition and understanding, not perfection or

stability.

This becomes especially important in modern cases, where allegations of incapacity are

sometimes tied to mental health struggles. Courts are cautious here. They resist the idea that

someone experiencing emotional distress or unconventional behavior is therefore incapable of making meaningful decisions. As one Ontario Superior Court of Justice decision noted, assuming incapacity based on mental health alone risks falling into harmful stereotypes.

On the other hand, there are situations where capacity truly is in doubt. If someone cannot

remember their assets, fails to recognize close family members, or is being manipulated by

others, those are red flags. Courts also look for “suspicious circumstances,” such as sudden and unexplained changes to a will, or involvement by beneficiaries in its creation.

Still, even unusual or unpopular choices, including disinheriting family members, does not prove incapacity. People are allowed to make decisions others disagree with. The law protects that freedom, so long as the decision was made knowingly and intentionally.

In the end, testamentary capacity draws a careful line. It protects vulnerable individuals from

exploitation, but it also respects personal autonomy; even when that autonomy leads to difficult or controversial outcomes. A valid will is not just about what is written on the page. It’s about the mind behind it.

If you would like to discuss capacity or any other estate planning matter in Ontario, please reach out to us at McDonald, Simon, Stewart & Reidy LLP. Our team is here to

provide expert legal guidance and help you understand your rights and obligations. Don’t

hesitate to contact us for a consultation - we’re ready to assist you!

Please reach out to us at info@mcdonaldsimon.com or call us at 519-273-2734.

Disclaimer: This blog should not be construed as legal advice. Each individual circumstance has nuances that need to be considered by a licensed legal professional and there is no one-size-fits- all answer in the law. If you require legal advice, please contact someone who is licensed with the Law Society of Ontario and is properly insured to provide legal services or practice law.