A will can be challenged in Ontario on four main grounds: lack of testamentary capacity, undue influence, fraud or forgery, and improper execution under the Succession Law Reform Act. Only someone with a legal interest in the estate — a named beneficiary, spouse, dependant, or intestate heir — can bring a challenge, and acting before probate is granted, often through a Notice of Objection, is strongly preferred.
- Ontario recognizes four main grounds to challenge a will: lack of testamentary capacity, undue influence, fraud or forgery, and improper execution.
- Testamentary capacity is assessed under the Banks v. Goodfellow test — a diagnosis like dementia alone does not automatically void a will; courts look at the testator's state of mind on the specific day it was signed.
- Undue influence means the testator understood what they were doing, but someone else overrode their free will — isolation, financial dependency, and persistent pressure are common indicators.
- You must have a legal interest in the estate to challenge a will — a beneficiary under the current or a prior will, a spouse, a dependant, or an intestate heir.
- A Notice of Objection, filed before probate is granted, can pause the process and protect your position while a challenge is investigated.
- Dependants who were inadequately provided for may have a separate claim for dependant's relief, even where the will itself is valid.
The Four Grounds for a Challenge
Ontario recognizes four main grounds for challenging a will: lack of testamentary capacity, undue influence, fraud or forgery, and improper execution under the formal requirements of the Succession Law Reform Act. A successful challenge requires more than simply disagreeing with how an estate was divided — it requires evidence supporting one of these specific legal grounds.
Lack of Testamentary Capacity
Testamentary capacity means the testator understood, at the time they signed the will, the nature of what they were doing, the extent of their assets, and their moral obligations to the people who might reasonably expect to benefit. Courts apply the Banks v. Goodfellow test to assess this. A diagnosis of dementia, illness, or medication effects can support a capacity challenge — but a diagnosis alone does not automatically void a will, since courts focus specifically on the testator's state of mind on the day the will was executed, which can vary even during a broader decline.
Undue Influence
Undue influence is different from incapacity: the testator fully understood what they were doing, but someone else overrode their free will and substituted their own wishes. Common indicators include:
- Isolating the testator from family members or trusted friends
- Controlling who the testator could speak to
- Financial dependency manufactured by the influencer
- Persistent pressure, threats, or emotional manipulation
- The influencer being present during the will-drafting process
- A will radically inconsistent with the testator's previously and consistently stated wishes
Undue influence is often only visible in hindsight, pieced together from multiple smaller indicators — which is why early legal investigation, including gathering witness accounts while memories are fresh, matters.
Fraud, Forgery & Improper Execution
A will can also be challenged where it was fraudulently procured or forged, or where the formal execution requirements under the Succession Law Reform Act were not met — such as missing witness signatures or an improperly executed document. These challenges tend to turn heavily on documentary and forensic evidence.
Who Can Challenge a Will
You need a legal interest in the estate to bring a challenge — as a named beneficiary under the current will or a prior one, a spouse or common-law partner, a dependant, or an intestate heir who would inherit if there were no valid will. Simply believing the outcome was unfair, without one of these interests, is not enough on its own.
Timing — Act Before Probate
Ontario's general two-year limitation period applies to will challenges, but acting before probate is granted is strongly preferred wherever possible. A Notice of Objection filed with the court can pause the probate process, protecting your position while the challenge is investigated and prepared — waiting until after probate has been granted makes the process considerably more difficult.
An elderly Ontario parent, isolated from most of the family in their final year by one adult child, signs a new will shortly before death leaving nearly everything to that one child. The other children file a Notice of Objection before probate is granted, pausing the process while evidence of undue influence — witness accounts of the isolation and the sudden change from prior wills — is gathered.
Dependant's Relief Claims
Separately from challenging the validity of a will, certain dependants — including a spouse or a child the deceased was financially supporting — can bring a dependant's relief claim where the will (even a valid one) failed to make adequate provision for them. This asks the court to vary the distribution, rather than invalidate the will itself.
Call our Ontario estate litigation lawyers at 416-274-2222 to discuss your situation confidentially.
Frequently Asked Questions
Four main grounds: lack of testamentary capacity (the person did not understand what they were doing), undue influence (someone overrode their free will), fraud or forgery, and improper execution under the Succession Law Reform Act's formal requirements.
No. Courts assess testamentary capacity under the Banks v. Goodfellow test, focused on the testator's state of mind on the specific day the will was signed — not simply whether a diagnosis existed at some point. Capacity can fluctuate, and a will made during a lucid period may still be valid.
Common indicators include isolating the testator from family or trusted friends, controlling who they can speak to, manufactured financial dependency, persistent pressure or emotional manipulation, the influencer being present during the will-drafting process, or a will that is radically inconsistent with the testator's previously and consistently stated wishes.
You must have a legal interest in the estate — as a beneficiary under the current will or a prior one, a spouse or common-law partner, a dependant, or an heir who would inherit if there were no valid will. Simply disagreeing with the outcome, without such an interest, is not enough to bring a challenge.
Ontario's general two-year limitation period applies, generally running from when the claim was discovered. Acting before probate is granted is strongly preferred, and a Notice of Objection can pause the process while your challenge is prepared.
Yes — dependant's relief is a separate claim available to certain dependants (such as a spouse or child the deceased was financially supporting) who were inadequately provided for, even where the will is otherwise entirely valid. It asks the court to vary the distribution, rather than invalidate the will.
The contested will (or the specific provisions successfully challenged) is set aside. Depending on the circumstances, this can mean an earlier valid will governs instead, or if no valid will exists, the estate is distributed according to Ontario's intestacy rules.