What Makes a Will Invalid in Ontario?

A will can be challenged or found to be invalid in Ontario where there is a legally recognized problem with how it was created, whether the testator had the legal capacity to make it, whether it truly reflects what the testator freely intended, or whether it meets the applicable requirements under Ontario law.

Being unhappy with a will, or receiving less than expected, does not make the will invalid. Ontario law gives people broad freedom to distribute their estates as they choose. The question of validity is different from the question of fairness.

The main grounds on which an Ontario will may potentially be found invalid are: lack of testamentary capacity, undue influence, fraud or forgery, lack of knowledge and approval of the contents, failure to meet execution requirements, and revocation by a later valid will or other lawful means.

What the Law Actually Requires for a Valid Will in Ontario

To understand what can make a will invalid, it helps to understand what a valid will requires.

Ontario’s Succession Law Reform Act (SLRA) sets out the requirements. There are two types of valid wills in Ontario:

Formal wills must be in writing, signed at the end by the testator (or by another person in the testator’s presence and at their direction), and signed by at least two witnesses in the testator’s presence. The witnesses must both be present at the same time when the testator signs or acknowledges the signature.

Ontario also permanently permits remote witnessing using audio-visual technology — at least one of the witnesses in a remotely witnessed will must be a licensee under Ontario’s Law Society Act, such as a lawyer or licensed paralegal. Wet-ink signatures are still required; electronic signatures are not permitted for wills under Ontario law, a point confirmed by the Ontario Superior Court in Gebremariam v. Menghesha, 2026 ONSC 54.

Holograph wills are entirely different. A holograph will is one that is wholly in the testator’s handwriting and signed by the testator. No witnesses are required. A will that is only partially handwritten — typed portions filled in, or pre-printed forms with handwritten sections — does not qualify as a holograph will.

The testator must generally be at least 18 years of age, or fall within specific limited exceptions set out in the SLRA.

An important development: section 21.1 and court-ordered validity

Since January 1, 2022, Ontario courts have had the authority to validate a will that does not strictly meet the execution requirements, provided certain conditions are satisfied. Under section 21.1 of the SLRA, the Superior Court of Justice may order that a document or writing — even one that was not properly executed — is valid and fully effective as the testator’s will, if the court is satisfied that it sets out the testamentary intentions of the deceased.

This means that a technical defect in execution does not automatically make a will invalid. An interested party can apply to the court to have the document validated. Courts have applied section 21.1 in cases involving unsigned drafts, wills missing a witness, and wills executed with procedural irregularities. However, the provision is not unlimited: it cannot be used to validate electronic wills, and courts require credible evidence that the document authentically reflects the testator’s final testamentary intentions. A document that was merely in progress, or which the deceased had not yet settled on, is unlikely to succeed.

What Can Make a Will Invalid in Ontario?

The Person Did Not Have Testamentary Capacity

For a will to be valid, the testator must have had what is called testamentary capacity — a specific legal standard — at the time the will was made.

The common law test, established in Banks v. Goodfellow (1870) and consistently applied by Canadian courts, requires that the testator:

Understood the nature of making a will and its effects
Understood the general extent of their property
Understood the claims of those who might reasonably expect to benefit
Was not suffering from a disorder of the mind that poisoned their affections, perverted their sense of right, or prevented the exercise of their natural faculties in disposing of their property

A person who has dementia, mental illness, or cognitive impairment does not automatically lack testamentary capacity. Capacity is assessed at the time the will was made — not at some earlier or later point — and the standard is specific to the act of making a will. Someone can lack capacity in some areas of life while retaining testamentary capacity. A lawyer’s careful approach to the will-signing meeting, including observations about the client’s functioning and understanding, is part of the reason drafting a will with professional assistance is recommended.

If testamentary capacity is genuinely in question, the issue almost always requires medical evidence, lawyer’s notes, and often witness testimony about the testator’s cognitive functioning around the time of the will’s execution.

The Will Was Created Through Undue Influence

A will may be challenged where the testator was subjected to undue influence — pressure or coercion so significant that it overrode their free will and caused them to make a will they otherwise would not have made.

Undue influence is not the same as ordinary influence, persuasion, or a close relationship. Family members, caregivers, and others regularly influence those they are close to, and this does not invalidate a will. The legal standard requires something more — effective coercion that substituted the influencer’s intentions for the testator’s own.

Circumstances that may raise concerns about undue influence include:

A beneficiary who was heavily involved in arranging or attending the will-signing
Sudden, dramatic changes to a well-established estate plan
Isolation of the testator from family or independent advisors
A testator in a position of significant dependence on a particular beneficiary
Evidence that the testator expressed different intentions before or after the will

These circumstances create concern. They do not, by themselves, prove undue influence. Courts require evidence that the testator’s actual free will was overcome.

The Will Was Not Properly Signed or Witnessed

Execution defects — missing witnesses, witnesses not being present at the right time, problems with how a signature was made — can raise questions about a will’s validity.

As discussed above, however, Ontario’s section 21.1 of the SLRA now gives courts the power to validate a document despite execution defects, provided the document is shown to authentically reflect the testator’s testamentary intentions. A technical problem in execution is therefore not automatically fatal — but it may require a court application to resolve, which adds time, cost, and uncertainty to the estate administration.

The Will Was Forged or Fraudulently Created

A forged will — one where the testator’s signature was not their own — is not a valid will. Similarly, fraud affecting the creation of a will can potentially render it invalid.

Fraud in the will context can include situations where the testator was deceived into signing a document they believed to be something other than a will, or where misrepresentations were made that caused them to dispose of their estate in a particular way.

Claims of forgery or fraud require evidence. A family member’s belief that a signature looks unusual is not the same as proof of forgery, and courts treat such allegations seriously. Expert evidence, comparison with known signatures, and thorough documentary investigation are often involved.

The Testator Did Not Know or Approve the Contents

A will can also be challenged on the basis that the testator did not have knowledge and approval of its contents — even where there is no evidence of undue influence or incapacity.

This ground typically arises where something about the circumstances of the will’s preparation raises a real question about whether the testator genuinely understood and intended what was written. Examples may include:

A testator with literacy, language, or vision limitations who may not have understood the document
A will prepared by a beneficiary or someone closely connected to a beneficiary
Circumstances suggesting pages may have been substituted or altered after execution
A difference between what the testator instructed and what the will actually says

Where suspicious circumstances exist, the court may require those propounding the will to affirmatively prove knowledge and approval before the will is accepted.

The Will Had Already Been Revoked

A will can also be found to have no legal effect not because of a validity problem, but because it was properly revoked before the testator’s death.

Under Ontario law, a will may be revoked by:

A later valid will. A subsequent will that contains a revocation clause, or is inconsistent with an earlier will, may revoke all or part of the earlier will.

A written document executed with the same formalities as a will. A formal written declaration of revocation, executed with the same requirements as a formal will, is also effective.

Deliberate physical destruction. The testator can revoke a will by burning, tearing, or otherwise destroying it with the intention of revoking it, either personally or by directing another person to do so in their presence.

What about marriage? Before January 1, 2022, marriage automatically revoked a will in Ontario in most circumstances. This changed significantly as a result of Bill 245, the Accelerating Access to Justice Act, 2021. For marriages taking place on or after January 1, 2022, marriage does NOT revoke a previously made will. Sections 15(a) and 16 of the SLRA, which contained the automatic revocation rule, were repealed. The Superior Court of Ontario confirmed in Bolotenko v. Wright Estate (2025 ONSC 1154) that this change is not retroactive. For marriages occurring before January 1, 2022, the old rule still applies.

What about separation or divorce? Section 17 of the SLRA provides that, unless the will states otherwise, a divorced or legally nullified marriage effectively removes the former spouse’s entitlements under the will — they are treated as having predeceased the testator. As of January 1, 2022, this same provision was extended to separated spouses, provided they meet the defined separation criteria (generally, living separate and apart as a result of marriage breakdown for at least three years, or having a separation agreement, court order, or family arbitration award, while still living separately at the time of death). Importantly, this does not revoke the will itself — it revokes specific provisions relating to the former or separated spouse.

A Quick Reference: Valid Concern vs. Not Enough on Its Own

Potential validity concern	Likely not enough on its own
Evidence testator lacked capacity at time of signing	Testator was elderly or in poor health
Coercion that overrode the testator’s free will	A beneficiary had a close or loving relationship with the testator
Serious execution defect (with no clear evidence of testamentary intent)	Minor technical error where intent is clear
Evidence signature was forged	Family member thinks signature “looks different”
Testator demonstrably did not understand the document	Testator received less than expected
A later will revokes an earlier one	A family member preferred the earlier will

Does a Beneficiary Witnessing a Will Make It Invalid?

No — not necessarily. Under section 12 of the SLRA, a beneficiary acting as a witness to a will does not automatically make the entire will invalid.

What may happen is that the gift made to that witness (or to the spouse of that witness) under the will is void. The rest of the will can remain valid and effective.

The court also has discretion under section 12(3) of the SLRA in certain circumstances. In Re: O’Neill Estate, the Ontario Superior Court validated a will under both sections 21.1 and 12(3) where a single witness was a beneficiary and had not attested the will in the usual way, relying on their uncontested evidence of the circumstances of execution.

Does Dementia Automatically Make a Will Invalid?

No. A dementia diagnosis, or a history of cognitive decline, does not automatically mean the person lacked the testamentary capacity required to make a valid will.

The key question is whether, at the specific time the will was made, the testator understood:

What a will is and what it does
The general extent of what they owned
Who might reasonably expect to benefit from their estate
What they were actually directing in the will

A person with early-stage dementia may still have the legal capacity to make a will. A person in the later stages of a severe cognitive condition may not. This assessment is highly fact-specific and almost always involves medical records, legal notes from the appointment, witness observations, and sometimes expert evidence.

Can a Will Be Invalid Because It Is Unfair?

No. Ontario law respects testamentary freedom — people are entitled to distribute their estates largely as they choose, including in ways that family members may consider unfair, unreasonable, or hurtful.

Simply being excluded from a will, or receiving less than expected, is not a ground for challenging its validity. The question in a validity challenge is not whether the distribution was fair, but whether the will is legally valid.

There are separate legal mechanisms that may allow certain dependants to make a claim against an estate — for example, under Ontario’s dependant support provisions in the SLRA — but these are distinct from challenging whether the will is valid. An estate dispute about executor conduct or administration is also different from a validity challenge.

Signs That a Will May Warrant Closer Examination

These are warning signs — not proof of invalidity.

A sudden, dramatic change to the estate plan made shortly before death
An unexpected new beneficiary replacing long-standing beneficiaries
A beneficiary who was heavily involved in arranging the will appointment
Concerns about cognitive functioning at the time of signing
A testator who was particularly isolated from family at the end of their life
Questions about whether the testator understood what was being signed
Multiple conflicting wills discovered after death
Questions about the authenticity of the signature
The will is inconsistent with what the deceased frequently expressed as their intentions

The presence of one or more of these factors suggests the matter may deserve legal advice. It does not mean a will challenge will succeed.

What Evidence Is Used in a Will Challenge?

Estate litigation involving a will challenge is evidence-driven. Potential sources of evidence include:

The original will and any earlier wills or codicils
The lawyer’s drafting file and notes from the signing appointment
Medical records relating to the testator’s cognitive functioning
Emails, letters, and text messages
Financial records showing the relationship between the testator and beneficiaries
Witness evidence from people who knew the testator
Expert evidence where capacity or medical questions are involved
Evidence about the relationships and dynamics in the family before and after the will was made

Access to some of this material — particularly the solicitor’s file — may involve legal proceedings to compel disclosure. Relevant privilege issues should be discussed with an estate litigation lawyer.

What Happens if a Will Is Found Invalid?

If a court finds that a will is invalid, the consequences depend on whether another valid will exists.

If there is an earlier valid will, that earlier will may govern the estate — assuming it was not itself revoked. If no valid will exists to govern some or all of the estate, the assets affected will be distributed in accordance with Ontario’s intestacy rules under the SLRA. Intestacy rules set out a prescribed order of distribution based on family relationships, without regard to the deceased’s personal wishes.

In some situations, only part of a will may be found invalid — for example, a particular gift may fail while the rest of the document remains effective.

Who Can Challenge a Will in Ontario?

Generally, those with a financial or legal interest in the estate may have standing to participate in a will challenge. This typically includes:

Beneficiaries named in the will being challenged
Beneficiaries named in an earlier will
People who would inherit on an intestacy if the will were set aside
In certain circumstances, creditors of the estate

Not everyone who has an opinion about the estate has standing to challenge the will. Whether a particular person has a sufficient legal interest to bring or participate in a challenge is a matter to discuss with an estate litigation lawyer.

Is There a Time Limit to Challenge a Will?

There is no single universal deadline for all will challenges in Ontario, and the answer depends on the type of proceeding, what has happened in the administration of the estate, and the applicable limitation legislation.

Generally, the Limitations Act, 2002 applies a two-year basic limitation period running from the date the claim was discovered or ought to have been discovered. However, different considerations apply depending on whether probate proceedings have been commenced, whether a Certificate of Appointment of Estate Trustee has already been issued, and whether estate assets have already been distributed to beneficiaries.

The important practical point is that waiting creates risk. Once an estate is fully administered and assets have been distributed, the practical ability to contest the will or obtain a remedy is significantly affected. Anyone who has concerns about a will should obtain legal advice promptly after learning of the issue.

I Think a Will May Be Invalid — What Should I Do?

If you have genuine concerns about the validity of a will, here are practical first steps:

Preserve the original will and related documents. Do not alter or destroy any documents.
Locate earlier wills or codicils if you are aware of any.
Keep relevant communications. Emails, letters, and texts relating to the estate or the deceased’s intentions may be relevant.
Write down why you have concerns. Document the specific facts that are troubling you while they are fresh.
Do not make accusations of fraud or undue influence without evidence.
Find out whether probate proceedings have started. If a Certificate of Appointment of Estate Trustee is being sought, there are procedural options that may be available, and timing can matter.
Speak with an Ontario estate litigation lawyer promptly.

When Should You Speak With an Estate Lawyer?

Legal advice may be particularly valuable when:

A will has changed significantly and unexpectedly near the end of life
There are real concerns about cognitive capacity when the will was signed
You believe a beneficiary may have exercised pressure or undue control over the testator
You have questions about the authenticity of the will or the signature
Multiple wills have been discovered
A probate application is underway and you want to understand your options
You are an executor dealing with a challenge to the validity of the will
You are a beneficiary who has been excluded and believe there may be a legal issue

At Estate Law Ottawa, we assist Ontario families, beneficiaries, and estate trustees with estate administration, probate proceedings, and estate disputes including wills and estate planning matters. If you are dealing with a disputed will or have concerns about estate administration, contact us to discuss your situation. Early advice almost always improves the available options.

Frequently Asked Questions

What makes a will legally invalid in Ontario?

A will may be legally invalid in Ontario if the testator lacked testamentary capacity when it was made, if the will was created through undue influence, if the testator did not know or approve the contents, if the will was forged or fraudulently created, or if there is a serious execution defect that cannot be cured by a court application under section 21.1 of the Succession Law Reform Act. A will can also lose effect if it has been properly revoked by a later will or through lawful revocation.

Does a will have to be witnessed in Ontario?

A formal will generally requires two witnesses present at the same time. However, a holograph will — one that is wholly in the testator’s own handwriting and signed by the testator — does not need witnesses. Additionally, since January 1, 2022, Ontario courts have the power under section 21.1 of the Succession Law Reform Act to validate a will that was not properly witnessed, if the document is authentic and sets out the testator’s testamentary intentions.

Can a handwritten will be valid in Ontario?

Yes. A holograph will — one that is entirely in the testator’s handwriting and signed by the testator — is legally valid in Ontario without any witnesses. The entire document must be handwritten; a form with handwritten sections does not qualify as a holograph will.

Can a beneficiary witness a will in Ontario?

Yes, but there may be consequences for that beneficiary’s gift. Under section 12 of the Succession Law Reform Act, having a beneficiary witness a will does not automatically make the entire will invalid. However, the gift to that witness (and potentially to their spouse) may be void. The court also has discretion in certain circumstances under section 12(3). A will drafted and executed with the assistance of an experienced estates lawyer avoids this problem entirely.

Does dementia make a will invalid in Ontario?

Not automatically. A dementia diagnosis does not by itself invalidate a will. The relevant question is whether the testator had testamentary capacity at the specific time the will was made — meaning they understood the nature of the will, the extent of their property, who might reasonably expect to benefit, and what they were directing. Capacity is highly fact-specific and requires careful assessment of the circumstances at the time of execution.

Can you challenge a will if you were left out?

Being left out of a will is not, by itself, grounds to challenge its validity. Ontario law allows testators to distribute their estates largely as they choose, including by excluding family members. If you believe there is a genuine legal issue — such as lack of capacity, undue influence, or fraud — that is a different question. There are also separate legal claims available to certain dependants under Ontario’s dependant support provisions, which do not depend on proving the will is invalid.

How do you prove undue influence in a will?

Proving undue influence in a will challenge requires evidence of coercion that overcame the testator’s free will — not merely that a beneficiary had a close relationship or a strong personality. Evidence that may be relevant includes testimony about the testator’s state of health and independence, the circumstances of the will’s preparation, the beneficiary’s role in arranging the will, and evidence of any isolation or control. Suspicious circumstances can shift the evidentiary burden in appropriate cases, but do not prove undue influence without more.

Who can challenge a will in Ontario?

Generally, people who have a legal or financial interest in the estate — such as beneficiaries under the challenged will, beneficiaries under a prior will, or those who would inherit on an intestacy if the will were set aside — may have standing to participate in a will challenge. Not every person with a view about the estate has a legal right to challenge the will. Standing should be discussed with an estate litigation lawyer.

How long do you have to challenge a will in Ontario?

There is no single universal deadline. Ontario’s Limitations Act, 2002 generally applies a two-year basic limitation period from the date the claim was discovered. Different considerations apply depending on whether probate has been granted and whether estate assets have been distributed. Delay creates practical and legal risk. Anyone with concerns about a will should seek legal advice promptly.

What happens if a will is found invalid in Ontario?

If a court finds a will invalid, an earlier valid will may govern the estate. If no valid will exists to govern all or part of the estate, Ontario’s intestacy rules under the Succession Law Reform Act will apply, distributing the estate according to a prescribed legal formula rather than the deceased’s personal wishes. In some circumstances, only part of a will may be found invalid while the rest remains effective.

Protecting the Estate — and Your Rights

When a will’s validity is genuinely in question, the consequences for the estate and those who depend on it can be significant. Whether you are a beneficiary with concerns about how a will was made, an executor facing a challenge, or a family member trying to understand what options exist, obtaining legal advice early is almost always the right first step.

At Estate Law Ottawa, we assist Ontario families with estate administration, probate, and estate disputes. If you have concerns about a will — whether as a beneficiary, an executor, or an interested family member — contact our office to discuss your situation. We will give you a clear explanation of your options without overpromising an outcome.

Disclaimer: This article is provided for general informational purposes only and does not constitute legal advice. Ontario wills and estate law involves complex legal and factual questions, and the applicable rules are subject to change. The information above reflects Ontario law as of August 2026. Reading this article does not create a lawyer-client relationship with J. Solomon Law Professional Corporation. If you have concerns about a will or an estate, please consult a qualified Ontario estate litigation lawyer before making decisions.