Yes, a will can be challenged in Ontario, but being excluded from the will or receiving less than expected is not, by itself, enough. A successful will challenge normally requires evidence of a recognized legal defect affecting the validity of the will — such as lack of testamentary capacity, undue influence, lack of knowledge and approval, improper execution, fraud, forgery, or other suspicious circumstances.
Ontario law starts from the principle that a person generally has the freedom to decide how their property will be distributed after death. A court does not rewrite a valid will simply because a beneficiary believes the result is unfair. The central question is whether the document truly represents the deceased’s valid testamentary intentions.
ME Law’s Estate Litigation practice addresses disputes involving wills, estates, executors, beneficiaries, and contested estate administration.
What are the main grounds for challenging a will?
1. Lack of testamentary capacity
The person making the will — the testator — must have had the mental capacity required to make a valid will when it was executed.
A capacity challenge may arise where there is evidence of cognitive decline, dementia, serious illness, medication effects, confusion, or another condition that calls into question whether the testator understood the nature of making a will, the property being disposed of, and the claims of those who might reasonably expect to benefit.
Capacity is assessed in the factual context surrounding the making of the will. Medical records, lawyer’s notes, witness evidence, prior wills, and the circumstances in which the new document was prepared may all become relevant.
2. Undue influence
A will may be challenged where another person overpowered the testator’s independent decision-making through coercion or improper influence.
Ordinary persuasion, family pressure, or involvement in the testator’s affairs does not automatically establish undue influence. The issue is whether the testator’s free will was effectively displaced.
Canadian courts distinguish undue influence from suspicious circumstances. Where undue influence is alleged, the burden of proving it generally remains on the person attacking the will.
3. Lack of knowledge and approval
A testator must know and approve the contents of the will.
This issue can arise where the document was prepared under unusual circumstances, contains unexpected provisions, substantially departs from prior estate plans, or was arranged by someone who benefits significantly from the change.
Where suspicious circumstances are established, the person seeking to uphold the will may be required to prove that the testator knew and approved its contents and possessed the necessary testamentary capacity.
4. Improper execution
Ontario’s Succession Law Reform Act sets formal requirements for the execution of wills. Subject to statutory exceptions, a will must be signed by the testator and properly witnessed.
However, a technical execution defect does not always end the analysis. Section 21.1 gives the Superior Court of Justice power, in qualifying cases, to declare a document valid if the court is satisfied that it sets out the deceased’s testamentary intentions even though it was not properly executed. That provision applies to qualifying deaths from January 1, 2022 onward.
5. Fraud or forgery
A will may also be attacked where there is evidence that a signature was forged, material facts were fraudulently misrepresented to the testator, documents were altered, or the purported will is not genuine.
These cases are highly evidence-dependent and may require handwriting evidence, document examination, financial records, witness testimony, or evidence concerning the circumstances in which the document appeared.
What are “suspicious circumstances”?
Suspicious circumstances are facts surrounding the preparation or execution of a will that raise legitimate concerns about capacity, knowledge and approval, or whether the testator’s free decision-making was compromised.
Examples may include:
- a major unexplained departure from prior wills;
- a vulnerable or dependent testator;
- a beneficiary playing a dominant role in arranging the new will;
- isolation of the testator from family members;
- unusual secrecy surrounding execution;
- substantial gifts to someone who participated in preparing or arranging the will.
Suspicious circumstances do not automatically invalidate a will. They affect how the evidence and burden of proof are assessed.
How is a will challenge started?
Ontario estate disputes are governed procedurally by Rule 75 of the Rules of Civil Procedure.
Where an application for a Certificate of Appointment of Estate Trustee is pending, a person with a financial interest may be able to file a Notice of Objection — Form 75.1. Ontario Court Services lists Form 75.1 specifically as the Notice of Objection used in contentious estate proceedings.
Depending on what has already occurred in the estate administration, the procedure may instead involve an application or motion for directions, a request for formal proof of the will, or other relief under Rule 75.
Timing matters. Once estate assets have been distributed, preservation and recovery issues can become more complicated. If there is a genuine concern about the validity of a will, obtaining advice early can help determine whether a procedural step is required to preserve the estate while the dispute is investigated.
For an overview of how litigation generally proceeds, see What is civil litigation in Ontario?.
What if the will is valid but I was unfairly excluded?
That may be a different legal issue.
An eligible dependant may potentially seek support from an estate even where the will itself is valid. Part V of Ontario’s Succession Law Reform Act allows the Superior Court of Justice to order adequate provision for the proper support of qualifying dependants where the deceased failed to make adequate provision.
A dependant-support claim is not the same as contesting the validity of the will. Different legal tests, evidence, procedures, and limitation rules apply.
This distinction is important because a person can have a potential estate claim even where there is no basis to invalidate the will itself.
How does ME Law assess a potential will challenge?
ME Law first identifies the actual legal issue rather than treating dissatisfaction with an inheritance as proof that the will is invalid.
The assessment may involve reviewing:
- the challenged will and earlier wills;
- the drafting lawyer’s file;
- medical and capacity evidence;
- communications involving the deceased and beneficiaries;
- financial and property records;
- the circumstances surrounding execution;
- evidence of dependency, influence, isolation, or unusual changes in the estate plan.
The objective is to determine whether there is evidence supporting a recognized challenge, what procedural steps may be required, whether estate assets need to be preserved, and whether litigation, negotiation, mediation, or another resolution strategy is appropriate.
If you are considering a challenge, What is a consultation at ME Law? explains how the initial legal assessment is structured.
Contact ME Law if you are concerned about the validity of a will or need advice about preserving your rights in an estate dispute.