Contesting a Will in Ontario: When Can You Challenge a Will, and How?

Learning that a loved one's will does not say what you expected — or that a will was changed late in life, or under questionable circumstances — can be painful and confusing. In Ontario, a will can be challenged, but only on specific legal grounds and only by certain people. Here is a plain-language overview of when and how a will can be contested.

Who can challenge a will?

Not just anyone can contest a will. Generally, you need a financial interest in the estate — for example, you are a beneficiary named in the will, you were a beneficiary under an earlier will, or you would inherit under Ontario's intestacy rules (the rules that apply when there is no valid will) if this will were set aside. Someone with no financial stake in the outcome usually cannot bring a challenge.

The main grounds for challenging a will

A will is not set aside simply because it seems unfair or because someone is unhappy with it. There must be a recognized legal ground. The most common are:

Improper execution. Ontario law sets out formal requirements for a valid will — generally, it must be in writing, signed by the person making it, and (for a typed will) witnessed by two people. A will that does not meet these formalities may be invalid. That said, since a 2022 change in the law, Ontario courts now have the power to validate a document that sets out a person's genuine testamentary intentions even if it was not signed or witnessed perfectly, so a technical slip does not automatically doom a will.

Lack of testamentary capacity. The person making the will must have had the mental capacity to do so. Under the long-established test from Banks v. Goodfellow, they must have understood that they were making a will, understood the general nature and extent of their property, and appreciated who might reasonably expect to benefit — free of any disorder of the mind that distorted those judgments. Capacity is often the central issue where a will was made during serious illness or cognitive decline.

Lack of knowledge and approval. A valid will must reflect what the person actually knew and approved. Where there are "suspicious circumstances" — for instance, a major beneficiary was closely involved in arranging the will — a court may require proof that the person truly understood and approved its contents.

Undue influence. A will can be challenged if the person was coerced — pressured to the point that the will reflects someone else's wishes rather than their own free choices. Undue influence is more than persuasion or ordinary family influence; it means the person's free will was overborne.

Fraud or forgery. A will obtained by deception, or a signature that was forged, is not valid.

Recent changes to Ontario's estate laws

A few changes that took effect on January 1, 2022 surprise people. Marriage no longer automatically revokes an existing will (it used to). A separated spouse can, in defined circumstances, be treated much like a divorced spouse and lose gifts under the will. And, as noted above, courts can now validate a will that does not strictly meet the signing and witnessing formalities. These rules apply to deaths on or after January 1, 2022.

How a challenge usually starts

When someone applies to the court to administer an estate under a will — an application for a Certificate of Appointment of Estate Trustee, often called "probate" — a person with a financial interest can file a Notice of Objection with the court. That objection pauses the process so the concerns can be examined. From there the matter can move into court-supervised steps: exchanging documents, questioning witnesses, and, if it is not resolved, a hearing.

A different option: dependant's support

Sometimes the real problem is not that the will is invalid, but that it leaves a spouse, child, or other dependant without adequate provision. Ontario law lets certain dependants apply for support from the estate, separately from challenging the will's validity. This is its own process, with its own deadlines.

The takeaway

Contesting a will is serious, fact-specific, and time-sensitive — estates get distributed, memories fade, and deadlines can apply. If you are worried about a will, it is worth getting advice early, before the estate is wound up, so your options are preserved and any objection can be filed in time.

This article is general information about Ontario law and is not legal advice. Will challenges depend heavily on the specific facts, and the law can change. Anyone considering contesting a will — or defending one — should speak promptly with a qualified Ontario lawyer about their own situation.