top of page

Mississauga Estate Litigation Lawyer

Challenging a Will is a hard decision. It is also fraught with emotion, on both sides. That’s why selecting the right Mississauga estate litigation lawyer is paramount. Challenging a Will will involve beneficiaries, guardians, executors, trustees, and estate lawyers. Litigating an estate in Mississauga is much like preparing to run a marathon:  it is a years-long endeavour.

As well, there may be dependents, such as adult disabled children, who were not properly provided for under the Will. These are called "dependent’s relief claims."

Based on our experience in litigating Mississauga estates, there are frequenly "difficult personalities" to deal with. 

The Mississauga Estate litigation lawyers at DeRusha Law Firm have the experience, the knowledge of Canadian Trust and Estates Law, and can properly advise you of your best course of action. We are clear communicators and we have empaphy for our clients who find, despite much negotiation and mediation, that their only legal remedy is estate litigation in court. We understand your pain. 

Haig DeRusha has a Masters Degree in Civil Litigation (Dispute Resolution) and has 25 years of experience in the Superior Court and Estate Courts. 


Syed Kabir  We will develop the best strategy, with clear objectives, and good planning, to obtain the best result for you and your family.​

Who has Grounds for Challenging a Will in Ontario?

The first hurdle in challenging a Will is to determine if, in fact, you have legal standing to do so. A Mississauga Estate Litigation lawyer at DeRusha Law Firm can advise you of your legal rights, and advise you of the best way forward.

This legal threshold is set out in Ontario’s Rules of Civil Procedure, Contentious Proceedings, Rule 75. Rule 75 sets out the procedure concerning claims against an estate. The companion rule, Rule 74, sets out the procedure for dealing with non-contentious issues of an estate.


Mississauga Estate Litigation Services

  • Allegations of Abuse of Powers of Attorney (POA)

  • Breach of Trust Actions

  • Challenging a Will

  • Defending a Will

  • Dependant Support and Relief Claims

  • Defence of Solicitor Negligence

  • Estate Trustee problems (breach of fiduciary duty)

  • Guardianships/Capacity

  • Mediation and Alternative Dispute Resolution

  • Passing of Accounts

  • Quantum Meruit Claims

  • Trustee/Executor Disputes

  • Unjust Enrichment Claims

  • Variation of Trusts

Reasons for Challenging a Will in Ontario

Speak to a Mississauga estate litigation lawyer, to first determine if you have a valid claim about challenging a Will in Ontario. In general, a Will can be challenged for these six reasons:

  1. You believe the Will is fraudulent—or even forged.

  2. The Will was not executed legally, meaning it was not signed in front of witnesses in the legally prescribed way, to make it a valid Will.

  3. The testator—the person making the Will—lacked knowledge and approval of the Will’s contents. To make a valid will, a person must be “of sound mind, memory and understanding.”

  4. You believe there was ‘undue influence’ exerted on the testator to sign a Will that bequeaths particular assets to specific people using pressure, coercion, threats, or other means.

  5. The testator lacked testamentary capacity and may have suffered from dementia or Alzheimer’s. “S/he didn’t know what s/he was signing, or even that s/he was making a Will.”

  6. The Will failed to provide adequately for a surviving spouse, children or other dependents, especially minor children or adult disabled children.


Challenging a Will: Invalid Reasons

It is important to understand that there are also grounds that are insufficient for challenging a Will. In Ontario, a Will does not have to be fair and treat all beneficiaries the same. Fairness is not a legal threshold that is legally defensible. A Mississauga estate litigation lawyer can advise you if your claim to challenging a Will is valid: 

  1. If the deceased promised you money, property, physical assets, or personal effect of sentimental value that was not written down in the Will;

  2. If you believe the Will treats you unfairly; or

  3. If the deceased wrote her/his own Will, used a Will Kit, or online Will writing software.

How Dementia Affects Challenging a Will

Sadly, many Canadians in their senior years will be afflicted with dementia, Alzheimer’s disease, or a combination of both. The legal term that is germane to both writing a valid Will and challenging an invalid Will is called "testamentary capacity." In other words, was the person making a Will (the testator) fully in command of his or her mental faculties?


For the first time in history, people are living long enough to lose their mental faculties. It’s called the ‘Rising Tide’:  annually, there are about 76,000 new cases of dementia diagnosed in Canada.

About 25% of Canadians aged over 85 are diagnosed with dementia.

About 66% of Canadians seniors with dementia are women.

Your Mississauga estate litigation lawyer at DeRusha Law Firm can give you specific advice if a loved one has been diagnosed with dementia and how that affects challenging or defending a Will.

bottom of page