Quick Answer: To contest a will in Ontario for lack of capacity, you must prove the deceased did not understand the nature of the will, the extent of their assets, or their moral obligations to dependents at the time of signing. This legal standard is known as the Banks v. Goodfellow test. Powell Litigation represents families navigating dementia, undue influence, and suspicious circumstances in estate disputes.
In the 2026 Ontario legal landscape, will challenges are increasingly focused on mental capacity and the circumstances surrounding how a will was signed. While many disputes involve family conflict, the court’s analysis is grounded in a specific legal test—not assumptions about age or diagnosis.
If you believe a loved one’s will does not reflect their true intentions, understanding how Ontario courts assess testamentary capacity is the first step.
For guidance on probate disputes and will challenges, explore our estate litigation services in Toronto.
Legal Insight from Powell Litigation
Powell Litigation is a Toronto-based civil litigation firm representing clients across the GTA in complex estate disputes. Our team regularly handles will challenges, undue influence claims, and fiduciary disputes in the Ontario Superior Court of Justice.
What is the Legal Standard for “Sound Mind” in 2026?
In Ontario, having a diagnosis such as dementia or Alzheimer’s disease does not automatically mean a person lacked the capacity to make a will. The court focuses on whether the individual had testamentary capacity at the exact moment the will was signed.
This means a person may still have legal capacity even with cognitive decline, provided they meet the legal standard at the time of execution.
The court’s role is not to determine whether the will is fair, but whether the person understood what they were doing when they made it.
The 4 Pillars of the Banks v. Goodfellow Test
The Banks v. Goodfellow test is the foundational legal standard used by Ontario courts to determine if a person had the mental capacity to sign a valid will.
To meet this test, the individual must have been able to:
- Understand the nature and effect of making a will
- Recall the general extent of their assets and property
- Appreciate the claims of individuals who may expect to benefit, such as spouses or children
- Be free from delusions or mental disorders that could influence how assets are distributed
If any of these elements are missing at the time of signing, the will may be vulnerable to challenge.
Red Flags: Suspicious Circumstances and Undue Influence
Ontario courts pay close attention to suspicious circumstances surrounding the creation of a will. When these factors are present, the burden of proof may shift to the party seeking to uphold the will.
Common red flags include:
- Isolation of the deceased from family members or long-time advisors
- A sudden or dramatic change from a previous will
- Secrecy surrounding the drafting or signing process
- Involvement of a beneficiary in preparing or arranging the will
As we see in recent 2025 and 2026 court trends, these circumstances often trigger deeper judicial scrutiny, especially where vulnerability or dependency is involved.
What Evidence Do You Need to Win an Estate Challenge?
Successfully challenging a will requires strong, evidence-based arguments. Courts rely heavily on documentation and witness testimony to reconstruct the circumstances surrounding the will.
Key evidence may include:
- Medical records showing cognitive decline or mental health concerns
- The drafting lawyer’s contemporaneous notes and file
- Testimony from family members, caregivers, or friends
- Retrospective capacity assessments from qualified medical experts
At Powell Litigation, we closely analyze the attending solicitor’s notes to identify inconsistencies or gaps in how the will was prepared and executed.
Estate Law Updates: Virtual Witnessing and Limitation Periods
Ontario’s Succession Law Reform Act has evolved to allow virtual witnessing of wills under certain conditions, including provisions under section 4(3). While this has improved accessibility, it has also introduced new risks related to undue influence and lack of oversight.
In virtual settings, it may be harder to determine who else was present or influencing the testator at the time of signing.
Ontario courts are also strictly enforcing limitation periods. In recent decisions such as Sparovec v. Smith, courts have emphasized that the two-year limitation period to challenge a will typically begins from the date the issue was discovered—not necessarily the date of death.
This makes early legal advice critical in protecting your rights.
Executor Duties and Fiduciary Concerns
Estate Trustees (executors) have a legal duty to act in the best interests of the estate and its beneficiaries. When concerns arise about misconduct, conflicts of interest, or misuse of estate assets, these issues may overlap with broader fiduciary disputes.
For more on how fiduciary breaches can impact estate administration, see our related discussion on breach of fiduciary duty.
Common Questions About Challenging a Will in Ontario
How long do I have to challenge a will in Ontario?
In most cases, you have two years from the date you discover the issue to start a legal challenge, although timelines can vary depending on the circumstances.
Can I challenge a will if I was left out?
Yes. You may be able to challenge a will if you were unfairly excluded, especially if there are concerns about capacity, undue influence, or dependent support obligations.
Does dementia automatically invalidate a will?
No. A diagnosis of dementia does not automatically invalidate a will. The court looks at whether the individual had testamentary capacity at the time the will was signed.
Protecting Your Rights in Toronto Estate Disputes
Probate disputes in Toronto and across the GTA often involve complex factual and legal issues, especially where mental capacity and family dynamics intersect. These cases require a detailed review of evidence, timing, and legal strategy.
If you are considering contesting a will in Toronto, working with an experienced estate litigation lawyer can help you assess the strength of your case and act before critical deadlines pass.
Contact Powell Litigation
Suspect a will is invalid? In Ontario, the clock starts ticking the moment you discover suspicious circumstances. Do not wait until estate assets are distributed.
Contact Powell Litigation for a strategic review of your case and take the first step in protecting your family’s legacy.