For a will to be valid, the person making it — the testator — must have testamentary capacity: the mental ability, at the time the will is made, to make it. This requirement protects both the testator, whose true wishes should be honoured, and the people around them, who should not be able to exploit a vulnerable person. The test that Ontario courts still use comes from a case decided over 150 years ago.
Banks v. Goodfellow (1870)
Banks v. Goodfellow is an English decision that has been applied in Ontario for generations. It sets out what a will-maker must be able to understand. In substance, the testator must:
- Understand the nature of the act of making a will and its effects — that they are deciding who receives their property when they die.
- Understand the extent of the property they are disposing of, at least in general terms.
- Be able to appreciate the claims of the people who might reasonably expect to benefit — such as a spouse or children — even if they choose not to benefit them.
- Not be affected by any disorder of the mind or delusion that distorts their sense of right or perverts the exercise of their natural faculties in disposing of their property.
Capacity is time-specific
A crucial point is that capacity is assessed at the moment the will is made, not before or after. A person whose cognition fluctuates may have capacity during a lucid period and lack it at another time. This is why the circumstances surrounding the signing — and any medical evidence about the testator's state that day — can matter so much in a dispute.
A diagnosis does not settle the question
Having a diagnosis such as dementia does not automatically mean a person lacked testamentary capacity. The legal question is not the label but the actual understanding the person had at the relevant time. Someone in the earlier stages of a cognitive illness may still meet the Banks v. Goodfellow test, while someone without any formal diagnosis might not. The evidence — not the diagnosis alone — decides it.
Reducing the risk of a challenge
- Making a will while clearly capable, rather than waiting until capacity is in doubt.
- Careful notes by the drafting lawyer about the testator's understanding.
- Contemporaneous medical assessment where capacity might later be questioned.
For education only. Capacity disputes are highly fact-specific and turn on the evidence about the testator's understanding at the time the will was made.
This article is general information for educational purposes only and is not legal advice. For advice on your situation, book a consultation.