How to Contest a Will in Ontario: Grounds and Deadlines

When someone dies, the will is often the first document that makes the loss feel real. Sometimes, it also raises questions. The wording does not sound like them. The division is not what the family understood it would be. A name appears that nobody expected, or an old one has quietly gone, and the change was made in the final year of their life.

If something about a will does not sit right with you, it is reasonable to ask about it. Ontario law has a process for testing whether a will is valid, along with rules about who may use that process and what they need to show.

This guide covers those rules: what counts as a legal ground, who may raise one, how a challenge typically moves through the court, what it may cost, and what may happen to an estate if a will does not stand.

Quick Start: Which Path Fits Your Situation

Four situations bring people to this question, and they lead in different directions. Find yours before reading on.

What Contesting a Will Means in Ontario

Ontario recognizes testamentary freedom, which means a person may generally decide who receives their property and need not divide an estate evenly. Courts start from the position that a signed will reflects what the person wanted, so a challenge may succeed only where a recognized ground is established.

This is different from a dependant support claim, which asks whether an estate makes adequate provision for someone the deceased was supporting, and which can proceed even where the will is entirely valid. Our estate litigation team handles both, and the two are sometimes raised together.

Who Can Contest a Will in Ontario

Lawyers call this standing, meaning the legal right to bring a matter before the court. A close friend, a long-time caregiver, or a distant relative with no financial stake typically cannot bring a challenge, however strongly they feel about what happened.

Standing is only the entry point. Having the right to raise a challenge is not the same as having evidence to support one.

The Grounds for Contesting a Will in Ontario

Lack of testamentary capacity

Testamentary capacity means the mental ability to make a will. The test Ontario courts apply is based on an English decision, Banks v. Goodfellow, and asks whether the person understood that they were making a will and what it does, had a general sense of what they owned, could appreciate who might reasonably expect to benefit, and was free from a disorder of the mind that distorted those judgments.

Capacity is decision-specific and time-specific. A diagnosis of dementia, a hospital stay, or strong medication does not by itself establish that someone lacked capacity on the day they signed.

Undue influence

Undue influence refers to pressure that overcame the person’s own wishes, so that the will records someone else’s intentions rather than their own. It is more than persuasion, affection, or a family member holding strong opinions.

Capacity and undue influence are separate grounds. Someone may have fully understood what they were signing and still have been unduly influenced into signing it. Therefore, the two are argued and proved differently.

Suspicious circumstances and knowledge and approval

Knowledge and approval means the person knew and agreed to what the will said. A court ordinarily presumes this. Where suspicious circumstances surround the making of the will, such as a beneficiary arranging the lawyer or a sudden change late in life, the Supreme Court of Canada’s decision in Vout v. Hay means the person putting the will forward may have to prove that the deceased understood and approved its contents.

Improper execution

Under the Succession Law Reform Act, a will typically must be in writing and signed by the person making it in the presence of two witnesses who are present at the same time and who then sign it as well. A holograph will, written entirely in the person’s own handwriting and signed by them, does not require witnesses.

Since January 1, 2022, section 21.1 of that Act has allowed the court to declare a document valid despite a defect in the signing formalities, where it is satisfied the document sets out the person’s testamentary intentions. A technical signing error no longer automatically invalidates a will.

Capacity or Influence: Telling the Two Apart

The distinction shapes what a lawyer looks for. A capacity challenge usually turns on medical records, the drafting lawyer’s notes, and how the person was functioning at the time. An undue influence challenge turns on relationships, dependency, isolation, and who arranged the will.

How a Will Challenge Typically Unfolds

Where probate has not yet been granted, an objection can be filed with the court to pause the process. Probate is the court step that confirms an estate trustee’s authority, and the resulting document is the Certificate of Appointment of Estate Trustee. Once that certificate has been issued and assets distributed, a challenge becomes procedurally harder, though not necessarily impossible.

Most estate matters in Ontario go through mandatory mediation before reaching a hearing, and many resolve there. The stages below are typical rather than fixed, and the order can change depending on what a judge directs.

Getting the Records Before You Can Prove the Case

That threshold comes from the Court of Appeal for Ontario in Neuberger Estate v. York. It works in both directions: a genuine concern can be investigated, while an estate is protected from expense driven only by disappointment.

In Rogers v. Ferretti, decided in 2026, the court found the threshold met and ordered broad production, including the drafting lawyer’s files, medical records, banking and investment records, and tax returns. Records of this kind often carry the evidence a challenge turns on.

How Ontario Courts Have Approached Timing

In Roberts v. Cowie, decided in 2026, the court refused to dismiss a will challenge as out of time and allowed it to proceed. The court reasoned that someone objecting to a will is not necessarily claiming damages, but is requiring the person putting the will forward to prove it. Whether that reasoning applies elsewhere may depend heavily on where the estate proceeding stands.

A dependant support claim runs on a different and much shorter timeline, typically six months from the grant of probate, which is one reason the two are worth separating early.

What a Challenge May Cost, and Who May Pay

Ontario courts have become less willing to treat estate litigation as an expense that the estate simply absorbs, particularly where a challenge appears speculative. That matters most in smaller estates, where a contested proceeding can consume much of what is being argued over.

An early assessment is usually the cheapest step available. It can show whether the evidence supports a recognized ground before anyone commits to litigation, and can equally confirm that no challenge is needed.

Common Mistakes to Avoid

• Treating unfairness as a ground. A will that divides an estate unevenly is not invalid for that reason alone, and a challenge built only on unfairness may not survive an early stage.
• Assuming a dementia diagnosis settles the question. Capacity is assessed for the particular decision at the particular time, so a diagnosis on its own does not prove someone lacked capacity when they signed.
• Waiting to see whether the family sorts it out. Delay can allow probate to be granted and estate assets to be distributed, which changes what steps remain available.
• Confusing a validity challenge with a dependant support claim. They are different applications with different requirements and different timelines, and pursuing the wrong one can cost time that matters.
• Expecting the estate to fund the challenge. Costs are discretionary, and an unsuccessful challenger may end up paying their own costs and a share of another party’s.
• Letting records disappear. Medical records, financial records, and the drafting lawyer’s file often carry the evidence a challenge turns on, and they are harder to assemble later. Careful will drafting and estate planning can also prevent most of these disputes in the first place.

Questions Families Often Ask

Where to Go From Here

A will challenge in Ontario is not about whether an estate was divided fairly. It is about whether the will reflects a decision the person was able to make and actually made freely. If something about a will genuinely does not fit what you knew of the person, that instinct is worth testing properly rather than carrying alone.

Qasim Ali, Principal Lawyer at Nihang Law, and our estate litigation team advise families across Toronto, Scarborough, and the wider GTA on both sides of these matters.

About the author

Qasim Ali

Principal Lawyer · Nihang Law Professional Corporation · Toronto & Scarborough, Ontario · Law Society of Ontario

Qasim Ali is the Principal Lawyer at Nihang Law Professional Corporation, serving clients across Toronto, Scarborough, and the broader Greater Toronto Area. He provides full-service legal representation across immigration, real estate, family law, criminal law, civil litigation, employment law, wills and estates, and business law.

Nihang Law is particularly recognized for its depth in immigration and real estate law — a combination that serves newcomers and growing families navigating both legal systems simultaneously.

Learn more about Qasim Ali →

Sources & References

• Succession Law Reform Act, R.S.O. 1990, c. S.26 — execution requirements, holograph wills, court-ordered validity under s. 21.1, and intestacy — www.ontario.ca/laws/statute/90s26
• Limitations Act, 2002, S.O. 2002, c. 24, Sched. B — basic two-year period and discoverability — www.ontario.ca/laws/statute/02l24
• Rules of Civil Procedure, R.R.O. 1990, Reg. 194, r. 75 — contentious estate proceedings — www.ontario.ca/laws/regulation/900194
• Neuberger Estate v. York, 2016 ONCA 191 — minimal evidentiary threshold — www.canlii.org/en/on/onca/doc/2016/2016onca191/2016onca191.html
• Rogers v. Ferretti, 2026 ONSC 2210 — production of solicitor, medical, and financial records — www.canlii.org/en/on/onsc/doc/2026/2026onsc2210/2026onsc2210.pdf
• Roberts v. Cowie, 2026 ONSC 1412 — limitation periods and will validity challenges — www.canlii.org/en/on/onsc/doc/2026/2026onsc1412/2026onsc1412.html
• Vout v. Hay, [1995] 2 S.C.R. 876 — suspicious circumstances, knowledge and approval — www.canlii.org/en/ca/scc/doc/1995/1995canlii105/1995canlii105.html
• Banks v. Goodfellow (1870), L.R. 5 Q.B. 549 — test for testamentary capacity, as applied in Ontario
• Ontario Superior Court of Justice — estates and civil procedure information — www.ontariocourts.ca/scj/
• Law Society of Ontario — public resources — lso.ca/public-resources