Contesting a Will in Canada: Grounds, Deadlines by Province

Contesting a will in Canada means either challenging its legal validity in court, on grounds such as incapacity, undue influence, or improper execution, or bringing a separate dependants' relief claim that leaves the will intact but asks a court to redistribute the estate to properly support a spouse or child.

Two very different kinds of will dispute

People often use the phrase contesting a will to describe two legally distinct proceedings. The first is a validity challenge, an argument that the document itself should never have been admitted to probate because something was wrong with how or when it was made. If a challenge succeeds, the will is set aside and an earlier will, or the intestacy rules, takes over instead.

The second is a dependants' relief application, called a wills variation claim in British Columbia. Here nobody disputes that the will is valid. Instead, a spouse or child who was left out, or left with too little, asks the court to redistribute the estate to provide adequate support. The will stands; the court simply varies how the money moves.

The two proceedings have different grounds, different people who can bring them, and very different deadlines, so it matters which one actually fits the facts before spending money on a lawyer.

Grounds to challenge a will's validity

Lack of testamentary capacity

A valid will requires the testator to have understood, at the time of signing, the nature of making a will, the extent of their property, and who would normally expect to benefit from it. Canadian courts still apply the common law test from Banks v Goodfellow, and look closely at medical records, the drafting lawyer's file notes, and witness evidence from around the signing date. A dementia or capacity diagnosis on its own is not conclusive; the real question is capacity at the moment the will was actually made.

Undue influence

Undue influence means someone coerced the testator into making a will that does not reflect their true wishes, overriding their free judgment. Unlike some contract or gift claims, undue influence over a will is not presumed just because the influencer had power over the testator. The person alleging it generally has to prove actual coercion, though the suspicious circumstances doctrine below can shift the practical burden.

Improper execution (formalities)

Every province sets formal requirements for a valid will, typically a signature by the testator and, for a formal witnessed will, signing in front of two witnesses who are both present at the same time. A holograph will, entirely in the testator's own handwriting, is valid in most provinces without any witnesses, but not as a traditional unwitnessed document in British Columbia, though BC's Wills, Estates and Succession Act lets a court cure a document that clearly reflects testamentary intent despite a formal defect. A missing witness, an undated signature, or witnesses who were not both present at the same time can all support a validity challenge.

Fraud or forgery

Fraud covers a will procured by lies, for example misrepresenting the contents of a different document the testator was asked to sign, while forgery challenges the authenticity of the signature or the document itself. These claims usually rely on handwriting analysis, paper and ink dating, and the surrounding circumstantial evidence.

Suspicious circumstances

Where the person who prepared the will, or who benefits substantially from it, was involved in instructing the lawyer or supervising the signing, Canadian courts, following the Supreme Court of Canada's decision in Vout v Hilderley, treat this as a suspicious circumstance. That shifts the practical burden back onto the person defending the will to prove the testator actually knew and approved its contents.

Who can challenge a will, and how long they have

Standing to allege a will is invalid is broader than standing for dependants' relief. Generally anyone with a financial interest the will affects, such as a beneficiary under an earlier will or an heir under the intestacy rules, can bring a validity challenge. A general validity challenge is ordinary civil litigation, so it typically falls under each province's basic limitation period, commonly two years from when the claimant knew or reasonably ought to have known of the grounds to sue, though courts retain some discretion and the clock does not always start on the date of death.

Dependants' relief and wills variation claims work differently. Only the categories of people named in the relevant statute, generally a spouse, common-law or adult interdependent partner, and children, can apply, and the deadlines are far shorter and stricter, typically a matter of months from the grant of probate rather than years.

Dependants' relief: when the will is valid but unfair

Ontario: Succession Law Reform Act, Part V

Part V of Ontario's Succession Law Reform Act lets a dependant, a spouse, parent, child, or sibling the deceased was supporting, or was legally obligated to support, immediately before death, apply for support if the will, or an intestacy, fails to provide adequately. The court weighs factors including the dependant's needs, the size of the estate, and the deceased's reasons for the dispositions made. An application must generally start within six months of the certificate of appointment of estate trustee, Ontario's grant of probate, being issued, though the court can allow a late application against any part of the estate not yet distributed.

British Columbia: the WESA wills variation claim

British Columbia's approach is notably broader than most of Canada. Section 60 of the Wills, Estates and Succession Act lets a spouse or child, with no separate dependant requirement to satisfy first, ask the court to vary an otherwise valid will if it does not make adequate provision for their proper maintenance and support, weighing both the moral and the legal obligations the testator owed them. Section 61 sets the deadline: the claim must be started within 180 days of the date the representation grant, probate or administration, is issued in British Columbia, a strict cut-off the court cannot extend.

Alberta: family maintenance and support

Part 5 of Alberta's Wills and Succession Act lets a defined family member, a spouse, adult interdependent partner, minor child, adult child unable to earn a livelihood because of disability, a full-time student child under 22, or certain grandchildren the deceased stood in place of a parent to, apply where a will or an intestate share leaves inadequate provision. An application must generally be commenced within six months of the grant of probate or administration, though the court can permit a later application against any undistributed part of the estate.

Province by province: the main claim and its deadline

Most provinces allow a court to extend the deadline in limited circumstances, generally only against estate assets not yet distributed, and British Columbia's 180-day period is applied strictly. Confirm the exact current wording against the province's own statute before relying on a specific number of days, since limitation provisions can be amended.

Quebec: a different framework entirely

Quebec's civil law tradition has no equivalent to the common law provinces' dependants' relief or wills variation action. A testator's freedom to distribute property by will is real but not absolute; it is constrained mainly by two separate mechanisms. First, the partition of the family patrimony divides certain family assets, including the family residence, vehicles, and retirement savings accumulated during the marriage or civil union, between spouses regardless of what the will says. Second, a surviving spouse or child who was owed support by the deceased may bring a support claim against the succession itself. Neither mechanism resembles a common law court redrawing a will's dispositions on a general fairness standard.

Burden of proof, mediation, and cost consequences

The person challenging a will's validity generally bears the burden of proving the ground alleged, except where suspicious circumstances shift the burden of proving due execution, knowledge, and approval back onto the party defending the will. In a dependants' relief or wills variation claim, the applicant instead has to show the provision actually made was inadequate; the burden does not automatically favour either side.

Provincial courts strongly encourage, and in some cases require, mediation before an estate dispute proceeds to trial. In several provinces the courts and the governing law society encourage, and in some cases require, parties to consider mediation or a collaborative resolution before a contested estate application proceeds to trial. Estate litigation is expensive and slow, and an unsuccessful challenger can be ordered to pay the estate's, or the successful party's, legal costs personally, on top of losing the underlying claim. Because both the grounds and the deadlines are unforgiving, anyone considering a challenge should get advice from a lawyer who practises in the relevant province as early as possible.

For the underlying estate process this cluster covers, see the Wills, Probate & Estates in Canada hub. For what a valid will and a well-run estate look like when there is no dispute, see Making a Will in Canada and Executor Duties in Canada.

Disclaimer: This article provides general legal information about contesting a will in Canada and is not legal advice. Grounds, standing, and limitation periods vary by province and can change; confirm current rules with the official provincial statute or court registry, or consult a lawyer who practises in the relevant province, before acting on a specific claim or deadline.