How to Contest a Will in Canada: Grounds and the Process

A 71-year-old widow in Burnaby leaves her entire estate to one of her three adult children — the one who moved in two years before she died. The other two siblings see the new will for the first time at the law office, ten days after the funeral. They have roughly six months to do something about it, and the clock starts before they have unpacked the question of whether they actually want to.

That is the practical shape of most Canadian will challenges. Someone close to the deceased reads the will, something does not sit right, and a clock they did not know about is already running. This guide covers the four legal theories Canadian courts recognize for challenging a will, who has standing under each, the time limits by province, and the realistic odds of each kind of claim succeeding.

The four grounds Canadian courts recognize #

A will challenge in a common-law province usually rests on one of four legal theories. The grounds can be combined in a single court application, and many real cases plead more than one in the alternative.

Lack of testamentary capacity. The testator did not have the mental capacity required by law to make a valid will. Canadian courts apply the test from Banks v Goodfellow (1870), updated through more than a century of Canadian decisions. The testator generally had to understand the nature and effect of making a will, the extent of their property, the moral claims of people who might expect to inherit, and the way the will distributed their assets. Capacity is assessed as of the moment the will was signed — not before, not after.

Undue influence. The will was not the product of the testator's own free will but of coercion by another person. Courts distinguish undue influence from legitimate persuasion or family pressure. The threshold is high — the challenger ordinarily must show that the testator's free will was actually overborne, not merely that someone was pushy.

Improper execution. The will was not signed and witnessed the way provincial law requires. Different rules apply to formal, holograph, and military wills, and the consequence of a defect varies. Some provinces (notably British Columbia under section 58 of WESA, and Ontario after its 2022 substantial-compliance amendment) give courts the power to rescue a substantially compliant will. Others still treat strict-formalities defects as fatal.

Suspicious circumstances and lack of knowledge and approval. The Supreme Court in Vout v. Hay set the framework that still governs.^[1] Suspicious circumstances around preparation, capacity, or coercion can be raised by a challenger. Once they are, the legal burden shifts back to the person propounding the will to prove that the testator knew and approved of the contents, and — if the suspicions go to capacity — that the testator had capacity. This is not a separate ground so much as a procedural lever that often gets combined with the others.

A fifth theory is technically not a will challenge at all but is the most common path to "fixing" a perceived unfair will:

Dependant support claims and BC wills variation. Provincial statutes let certain people — most often a spouse, common-law partner, or dependent child — apply to a court to redirect estate assets to themselves, even when the will is otherwise valid. The will is not declared invalid. The distribution is varied.

Who has standing to challenge #

Standing depends on the legal theory.

For validity-based challenges (capacity, undue influence, improper execution, suspicious circumstances), anyone who would inherit if the will were declared invalid has standing. That generally means beneficiaries under a prior will, and people who would inherit on intestacy under the province's intestacy rules — usually the spouse, children, parents, and siblings in declining order.

For dependant support claims, the statutes are more specific. Ontario's Succession Law Reform Act defines "dependants" to include the deceased's spouse (including a common-law partner who meets the statute's cohabitation test), parents, children, and siblings to whom the deceased was providing support or was legally obligated to support immediately before death.^[2]

For BC wills variation under section 60 of WESA, the rules are unusually broad in Canadian context. Only the deceased's spouse (including a common-law spouse in a marriage-like relationship for at least two years) and biological or legally adopted children can apply — but the adult-child applicants do not need to prove ongoing dependency.^[3] An independent, adult, employed child can apply on the basis that the will did not make "adequate, just, and equitable" provision for them. This stands BC apart from every other Canadian common-law province, where adult independent children generally have no standing to challenge a will on fairness grounds.

Time limits — the deadlines that catch people off guard #

Time limits are unforgiving in estate litigation. A meritorious claim filed one day after the limitation period generally fails, no matter how strong the underlying facts.

The deadlines that come up most often are:

The Ontario six-month dependant support deadline is the trap most commonly missed.^[2] The clock starts not from the date of death but from the day the certificate of appointment is issued — which can be many months after death. Once the certificate exists, the period runs whether or not the family knew about it. Courts have a narrow discretion under section 61(2) of the SLRA to allow late claims, but only against the undistributed portion of the estate.

The BC 180-day deadline runs from the grant of probate as well, and section 61 of WESA additionally sets out service requirements that must be met after filing.^[3]

If you are reading this because you think you might want to challenge a will, the first practical step is to find out the date the grant of probate was issued in the province where the estate is being administered. Every other strategy choice flows from where you are in that window.

What the process actually looks like #

The mechanics differ a little by province, but the rough sequence is consistent.

Engage an estate-litigation lawyer. Will challenges are not DIY territory, and most lawyers offering wills work do not litigate them. A focused estate-litigation practitioner is the realistic starting point. Many take cases on a partial contingency where the merits look strong, but expect significant up-front cost on disclosure and expert work.

Preserve evidence. Lawyer's drafting files, medical records, banking records around the time of the will, and witness statements from people who knew the testator are usually the heart of a capacity or undue-influence case. Estate solicitors are generally required to keep notes from will-drafting meetings, and those notes are often decisive at trial. Securing them early — usually by court order in contested matters — matters a lot.

Caveat or notice of objection. Most provinces let an interested party file a document with the probate court that essentially freezes the grant of probate until the dispute is resolved. The terminology varies — caveat in some provinces, notice of objection in Ontario.

Pleadings and discovery. The standard civil litigation sequence applies — statements of claim, statements of defence, document production, examinations for discovery, and expert reports (medical experts for capacity cases, forensic accountants where assets are complex).

Mediation. Most provinces require or strongly encourage mediation before trial. Estate disputes settle at mediation more often than not, because the cost of trial and the family fallout from a contested hearing weigh on everyone.

Trial. A small minority of cases reach trial. Capacity and undue influence trials are document- and expert-heavy and can run a week or more.

Realistic odds of success #

The four grounds do not all have similar success rates. The general pattern in Canadian case law:

Capacity challenges succeed where there is a clear medical record of cognitive decline contemporaneous with the will-signing, and where the will represents a sharp departure from prior estate plans. Where the testator had a single drafting lawyer who recorded a capacity assessment, capacity challenges generally face an uphill climb.

Undue influence claims are difficult. The challenger carries the burden, the threshold is high, and the evidence is usually circumstantial. Suspicious-circumstances pleading (per Vout v. Hay) is often used to shift evidentiary weight back to the propounder, which makes some difference.^[1]

Improper execution challenges generally turn on whether the province has substantial-compliance legislation. In BC under WESA section 58 and Ontario under its 2022 amendments, a court can sometimes save a will despite execution defects. In other provinces, strict formalities still rule and a defective will is more likely to fail.

Dependant support and BC wills variation claims succeed at materially higher rates than validity challenges, partly because the underlying question — has the testator made adequate provision for a dependent spouse or child — does not require proving anyone did anything wrong. They are also less inflammatory family-dynamics-wise, since the will is not being attacked as a fraud or forgery.

What it costs #

Realistic ranges for a contested will challenge through trial in a common-law province start in the low five figures for a quick-settling matter and routinely run into six figures for a contested trial. Mediation can keep total costs in the $25,000 to $75,000 range. Many will challenges become economic only above estates of a few hundred thousand dollars — though dependant relief claims sometimes proceed regardless because they go to actual support needs, not just inheritance amounts.

Costs awards are common at the end of estate litigation. Historically, Canadian courts often ordered costs paid out of the estate; the modern trend in most provinces is to apply ordinary costs principles, which means a losing challenger can be ordered to pay the estate's costs personally.

What we focus on at It's Simple Will #

The simple, hardest truth about will challenges is that the best ones are the ones that never need to happen. A clearly drafted, properly witnessed will, signed at a time the testator's capacity is well documented, made after open conversations with the people who might feel surprised by its contents, is a will that does not get contested at trial.

The Will Creator at app.itssimplewill.ca produces a will compliant with the province where you live, generated from your answers and following the formal execution rules for each common-law jurisdiction in Canada. Pairing the will with the Life Discovery Kit reduces post-death surprise — the executor and the family are not learning about assets and reasoning for the first time on the worst week of their lives.

If you are reading this because someone you love has just died and the will does not match what you understood would happen, your first move is to find out the date of probate and how the limitation clock is running. Then a focused estate-litigation lawyer in the province where the estate sits. Almost nothing else needs to happen today, but those two things probably do.

Related reading: what does an executor do in Canada, what is probate in Canada, and dying without a will in Canada.