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Estate Litigation in Ontario: How an Estate Dispute Works

Learn how an estate dispute moves through Ontario courts, from notices and objections to mediation, accounts, removal of a trustee and trial.

Wills & Estates6 min readTSLBy the Treadstone Law Team · OntarioUpdated November 1, 2026
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Key takeaways
  • Many Ontario estate disputes start with a formal notice, such as a Notice of Objection (Form 75.1) filed before a certificate of appointment is issued.
  • Some estate lawsuits are sent to mandatory mediation under Rule 75.1 unless the court grants an exemption.
  • Time limits can be short, so it is worth finding out early which deadline applies to your claim.

If you are a beneficiary or an estate trustee and a court fight over an estate has started or looks likely, the process can feel confusing. Estate disputes follow their own rules, and the steps are often different from an ordinary lawsuit.

This article walks through the stages most estate disputes pass through in Ontario, from the first notice to a hearing or trial. Every estate is different, so treat it as a map and not as advice for your situation.

How estate disputes usually begin

Most estate disputes start with a worry about one of a few things: whether a will is valid, whether the trustee is doing the job properly, or whether someone has been left without support. The first step depends on which worry you have.

Early steps: objections, notices and the right court

An objection is made by filing a Notice of Objection (Form 75.1) with the registrar or the Estate Registrar for Ontario, stating the nature of your interest and of your objection. If the Registrar tells the probate applicant that the notice has been filed, the applicant must send a notice to the objector (Form 75.3) and file a copy with the court along with an affidavit of service.

In the Toronto Region, the Estates List of the Superior Court of Justice hears estate, trust and capacity matters, including Rule 74 and 75 proceedings and guardianship proceedings. Rule 75.06 gives the court considerable discretion and flexibility to set a process for resolving a contested estate. Procedures differ by region, so the practice direction for the court where your case will be heard matters.

In Toronto, a party seeking an urgent Estates List hearing must complete an Urgent Hearing Request form through the Ontario Courts Public Portal, and parties on motions and applications must file a costs outline through the Portal before the hearing.

Mediation before a hearing

Under Rule 75.1, certain lawsuits about estates, trusts and substitute decisions are referred to mandatory mediation unless the court grants an exemption. Mediation is mandatory in certain estates proceedings, including contested passings of accounts, claims against an estate, and proceedings under the Substitute Decisions Act, 1992. The Ontario government says the Mandatory Mediation Program operates in Toronto, Ottawa and Windsor. Whether it applies to your case depends on where the proceeding is.

The timelines are tight.

The court's directions order sets the cost of mediation and how it is shared, and parties pay mediators directly.

The main kinds of fight and what a court can do

Type of disputeWhat the court looks at
Challenge to a willThe person putting forward the will has the legal burden of proving due execution, knowledge and approval, and testamentary capacity. Once due execution is proved, the challengers carry an evidential burden, and the legal burden returns to the person putting forward the will if they introduce evidence of suspicious circumstances. Undue influence is the exception: the challengers must prove it, and suspicious circumstances do not shift that burden.
Passing of accountsThe judge may inquire into any complaint by a person interested in the accounts and may order the trustee to pay damages or other sums to the estate.
Removing a trusteeThe court may remove a personal representative, but courts treat removing someone the deceased specifically chose as a serious matter.
Dependant supportThe court sets the amount and duration of support by considering all the circumstances.

If a dispute involves land, starting a proceeding is not notice to non-parties until the court issues a certificate of pending litigation and it is registered. The court may later discharge it on grounds such as the claimant having no reasonable claim to the land interest.

Time limits and what to do next

As a general rule, most claims must be started within two years after the day the claim was discovered. Dependant support claims are an exception: no application for dependant support may be made more than six months after the grant of letters probate of the will or of letters of administration, and the Limitations Act, 2002 lists that provision as applying instead of the general two-year rule. The court may allow a late application, but only against any portion of the estate still undistributed on the date of the application.

Claims by or against a deceased person's estate for torts or injuries (other than libel and slander) must be started within two years of the death. Separately, the general two-year period under the Limitations Act, 2002 does not run while a claimant is incapable of starting a proceeding and has no litigation guardian. Whether that applies to a claim with its own time limit depends on the facts, so it is worth confirming with a lawyer. Filing a notice of objection to accounts in response to a trustee's application to pass accounts does not start a proceeding, so the two-year period does not apply to it.

Frequently asked questions

Do all estate disputes end up in a trial?

No. Some are resolved at mediation or after an exchange of positions. Mediation is mandatory for certain estate proceedings unless the court grants an exemption.

Can a beneficiary force a trustee to show the accounts?

A beneficiary can apply to the court to require an executor or administrator to account. No Ontario law requires a trustee to pass accounts at fixed intervals, so the court usually becomes involved only when someone asks.

Can I stop an estate from being given out while the dispute is on?

Whether and how depends on the type of claim. For a dependant support claim, a personal representative served with notice must not distribute the estate until the court has disposed of the application, unless everyone entitled to apply consents or the court orders otherwise.

Who pays for mediation?

The court's directions order sets the cost of mediation and how it is shared, and parties pay mediators directly.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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