For most families, settling a loved one’s estate is a matter of paperwork and patience. But a signed, witnessed will is not always the end of the story. In Ontario, a will can be challenged, an executor can be removed, and a person left out entirely can still bring a claim against the estate. Estate litigation has become more common across the Greater Toronto Area as family structures grow more complicated and estates grow more valuable, and understanding how these disputes actually unfold can help beneficiaries and executors know where they stand.

When Can a Will Be Challenged?

A will is presumed valid once it has been properly executed, but that presumption can be rebutted. Ontario courts recognize several grounds for contesting a will, and most disputes fall into one of a handful of categories.

Lack of testamentary capacity. The person making the will must understand the nature of the document, the extent of their property, and the people who might reasonably expect to inherit. Where a will was made during cognitive decline, a challenger may argue the deceased did not meet this threshold.

Undue influence. If someone in a position of trust pressured or coerced the deceased into changing their will, the resulting document may not reflect the deceased’s true intentions. These cases often involve a caregiver, a family member, or a new partner who benefited from a late-in-life change.

Improper execution or suspicious circumstances. A will that was not signed and witnessed according to Ontario’s formal requirements, or one produced under circumstances that raise red flags, can be set aside by the court.

Dependants Have Rights Even When They’re Left Out

One of the most misunderstood aspects of Ontario estate law is that a validly executed will does not give the deceased complete freedom to disinherit. Under the Succession Law Reform Act, certain dependants—including spouses, children, and others the deceased was supporting—can apply to the court for adequate provision from the estate if the will fails to provide for them. Even a clearly written will can be varied by a judge where a dependant support claim succeeds, which is why being cut out of a will is not necessarily the final word.

When the Executor Is the Problem

Disputes don’t always center on the will itself. Sometimes the conflict is with the person administering the estate. An estate trustee (the Ontario term for an executor) owes a fiduciary duty to the beneficiaries and must account for every dollar. Where an executor delays distribution unreasonably, mismanages assets, self-deals, or refuses to communicate, beneficiaries can ask the court to compel a formal passing of accounts or, in serious cases, to remove and replace the trustee. Breach of fiduciary duty claims are among the more contentious matters that reach Ontario’s Superior Court of Justice, which hears contested estate proceedings.

Capacity, Powers of Attorney, and Disputes Before Death

Not every estate dispute waits until after a death. Conflicts frequently arise over powers of attorney and the decisions made by an attorney for property or personal care. Ontario’s Substitute Decisions Act governs these arrangements, and disagreements over whether an attorney is acting in the incapable person’s best interests can escalate into litigation while the person is still living. These cases often foreshadow the estate disputes that follow.

How These Disputes Actually Get Resolved

Contrary to what television dramas suggest, most estate disputes in Ontario never reach a full trial. Contested estate matters are governed by specialized procedural rules, and the courts strongly encourage mediation, which is mandatory for estate proceedings in Toronto. A significant share of cases settle once the parties exchange evidence and understand the true strength of their positions. That said, the ones that do proceed can be emotionally draining and financially significant, particularly where family relationships and substantial assets are both on the line.

The practical takeaway is that timing and evidence matter enormously. Ontario imposes limitation periods on many estate claims, and waiting too long can extinguish an otherwise valid case. Anyone weighing whether to challenge a will, defend an estate, or pursue a dependant support claim benefits from early, experienced guidance. Families navigating a contested estate in the GTA often turn to Toronto estate litigation lawyers to assess the merits of a claim before deadlines pass and positions harden.

The Bottom Line

A will carries real legal weight, but it is not untouchable. Between capacity challenges, undue influence claims, dependant relief applications, and executor accountability, Ontario law provides several avenues for those who believe an estate is not being handled fairly. Knowing these paths exist—and acting within the applicable deadlines—is what separates a resolved dispute from a missed opportunity. For anyone facing one of these situations, confirming your rights with a qualified professional early is almost always the right first move. You can verify that any lawyer you consult is in good standing through the Law Society of Ontario.

Disclaimer: This article is provided for general informational purposes only and does not constitute legal advice. Estate law varies by jurisdiction and by the facts of each case. Reading this article does not create a lawyer-client relationship. If you are dealing with an estate dispute in Ontario, consult a licensed lawyer about your specific circumstances.