How To Challenge A Will In Ontario?

Challenging a Will in Ontario is not simply a matter of disagreeing with the outcome. Courts require real evidence: specific, credible, and connected to the legal grounds you are relying on. This article explains exactly what that evidence looks like.

Before discussing evidence, it helps to understand what you are actually trying to prove. In Ontario, the main grounds for challenging a Will are:

• Lack of testamentary capacity: the person who made the Will did not understand what they were signing.
• Undue influence: someone pressured or manipulated the testator into making the Will.
• Suspicious circumstances: something about the Will or the circumstances surrounding it raises serious doubts about its validity.
• Improper execution: the Will was not signed and witnessed correctly under Ontario law.
• Fraud or forgery: the Will was fabricated or the testator’s signature was forged.

The evidence you need depends on which ground you are relying on. Most contested cases involve capacity, undue influence or both.

Ontario courts do not require you to prove your case at the outset. Before you can access the medical records, financial documents, and solicitor files, you must first clear a lower bar: the minimal evidentiary threshold (see Patell v. Patell, where our lawyers successfully met this test).

As confirmed in Rogers v. Ferretti, 2026 ONSC 2210, you must present some evidence that, if accepted, could call the Will’s validity into question. You do not need to win at this stage. You simply need to show the court that there is enough to justify a deeper investigation.

Once you clear that threshold, the court can order broad productions of:

• Medical and healthcare records;
• Financial and banking records;
• Solicitor files and Will instructions;
• Investment and real estate documents;
• Tax returns.

Clearing this threshold is step one. Building your full case comes after.

For a valid Will, the testator must have understood four things at the time of signing: the nature of making a Will, the extent of their property, who their close family members were, and how the Will affects those people.

If you believe the testator lacked this understanding, here is the evidence that matters:

Medical records are the foundation of almost every capacity challenge. 

• Diagnosis of dementia, Alzheimer’s, delirium, or other cognitive conditions;
• Hospital admission notes and discharge summaries from around the time the Will was signed;
• Physician and specialist notes describing confusion, disorientation, or memory loss;
• Cognitive assessment scores;
• Medications prescribed that are known to impair judgment or cognition;
• Any documented episodes of not recognizing family members.

Even without a formal diagnosis, clinical notes describing confusion or disorientation can be powerful evidence of incapacity.

The solicitor who drafted and witnessed the Will is a critical witness. Courts examine:

• Did the lawyer meet privately with the testator, without the beneficiary present?
• Did the lawyer take notes recording their capacity assessment?
• Did the testator give instructions independently, in their own words?
• Did the lawyer have any concerns at the time?
• How long was the meeting? Was it rushed?

Suspicious timing is powerful evidence. Courts pay close attention to:

• A Will signed days or weeks before death;
• A Will signed during a hospitalization or acute illness;
• A Will signed the same day the testator first met the lawyer;
• Rapid changes to a longstanding estate plan without explanation.

Undue influence does not require physical force or obvious threats. It can be quiet, subtle and difficult to see from the outside. Courts define it as influence exercised to such a degree that it destroys the free will of the testator, replacing their genuine wishes with someone else’s.

“Influence is undue when it is exercised to such a degree as to amount to force and coercion, destroying the free agency of the testator.”
— Craig v. Lamoureux, [1920] AC 349 (PC)

Evidence of undue influence typically includes:

Courts examine the power dynamic closely:

• Did the beneficiary control the testator’s finances, medication, or daily care?
• Was the testator financially or emotionally dependent on the beneficiary?
• Did the beneficiary arrange the lawyer, drive the testator to the appointment, and sit in on the meeting?
• Did the beneficiary stand to gain dramatically from the new Will?

Isolating an elderly or vulnerable person from other family members is one of the clearest warning signs of undue influence:

• Evidence that the beneficiary controlled who could visit or call;
• Family members suddenly cut off from contact without explanation;
• The testator moved in with the beneficiary shortly before the Will changed;
• Friends and family reporting they were turned away or discouraged from visiting.

A sudden departure from a longstanding estate plan — particularly one that benefits someone who recently entered the testator’s life — is a significant red flag:

• Prior Wills that treated all children equally, followed by a new Will cutting some out entirely;
• A new beneficiary who was not previously mentioned in any Will;
• Changes made shortly after the testator became dependent on one particular person;
• No rational explanation for why the testator would have changed their mind.

Under Ontario’s Succession Law Reform Act, a Will must be signed by the testator in the presence of two witnesses, both of whom must also sign in the testator’s presence. If this did not happen correctly, the Will may be challenged.

Evidence here is more straightforward:

• The Will itself: does it contain the required signatures and witness attestation?
• Witness testimony: were both witnesses physically present when the testator signed?
• Evidence that a witness is also a beneficiary, which can affect the gift to that witness.
• Evidence that the testator did not actually sign — or that the signature was not their own.

Fraud and forgery cases require forensic evidence:

• Handwriting analysis by a qualified forensic document examiner comparing the signature to known genuine examples.
• Expert evidence on the authenticity of the document itself.
• Witness evidence that the testator never signed the document or was not present when it was supposedly executed.
• Financial records showing unusual transfers or asset movements around the time the Will was signed.

At Pinto Shekib LLP, we act in complex Ontario Will challenges involving capacity, undue influence, suspicious circumstances, and fraud. Contact us at 416.901.9984 or info@pintoshekib.ca.