When Does Wilful Concealment Pause Ontario's 15-Year Limitation?

Can wilful concealment stop Ontario’s 15-year limitation clock?

Yes — but only if the concealment is actually what prevented you from learning the facts. Ontario’s Court of Appeal confirmed in Paterson v. Royal Bank of Canada, 2026 ONCA 480 (CanLII) that the wilful-concealment exception in s. 15(4)(c) of the Limitations Act, 2002 requires a direct causal link between the defendant’s hiding of information and the plaintiff’s inability to discover the claim. If you already had the key facts from a reliable source, the exception does not apply.

What is Ontario’s ultimate limitation period?

Ontario’s ultimate limitation period is an absolute 15-year deadline that runs from the date of the act or omission that caused your loss — not from when you found out about it. Unlike the basic two-year limitation period, which is subject to discoverability principles, the 15-year period is designed to give defendants finality. Once it expires, a claim is permanently barred, even if the plaintiff only recently learned of the harm. The Limitations Act, 2002 does provide limited exceptions, including for wilful concealment, but courts interpret those exceptions narrowly.

What does “wilful concealment” mean under the Limitations Act?

Wilful concealment means the defendant deliberately hid the facts that would have allowed the plaintiff to discover and pursue a claim. It is not enough to allege, in general terms, that the other side was secretive or uncooperative. The Court of Appeal confirmed that a bare allegation of concealment in a statement of claim — without factual support — will not survive a Rule 21 motion to strike. The concealment must be pleaded with enough substance to show that it actually caused the plaintiff’s ignorance of the material facts.

When does knowledge from a “reliable source” start the clock?

Knowledge starts the limitation clock running as soon as you have enough information from a reliable source to understand the nature of the loss and who is responsible — even if you do not have complete certainty or every detail. The Court applied a discoverability standard that mirrors the basic limitation period analysis: once a reasonable person in your position would have investigated and discovered the claim, time begins to run. In this case, the court found that the plaintiff had that level of knowledge by 2004, meaning the 15-year ultimate period had long since expired by the time the claim was issued.

Can a limitation defence be decided at the pleadings stage in Ontario?

Yes, in clear cases it can. A Rule 21 motion allows a defendant to ask the court to strike a claim before any evidence is gathered, on the basis that it discloses no reasonable cause of action. The standard is demanding: the motion succeeds only if it is “plain and obvious” that the claim cannot succeed. For limitation defences, this means the court accepts all the facts in the statement of claim as true — but it does not have to accept bald legal conclusions. The Court of Appeal confirmed that where the pleaded facts themselves reveal the claim is out of time, striking at the pleadings stage is appropriate and does not require a trial.

What happened with costs in this case?

The motion judge ordered no costs, apparently relying on a perception of animosity between the parties — but without inviting submissions from either side on that point. The Court of Appeal found this was an error in principle. Costs are a discretionary remedy, but that discretion must be exercised in accordance with the factors in Rule 57.01 of the Rules of Civil Procedure, and parties are generally entitled to make submissions before an adverse costs order is made. The no-costs order was set aside, and the Court fixed costs on a partial indemnity basis in favour of the successful parties.

Practical takeaways for plaintiffs and their counsel

• Act early. If you believe you have a claim, consult a lawyer as soon as possible. Ontario’s 15-year ultimate limitation period can bar a claim even if you only recently discovered the full picture.
• Pleading concealment is not enough. A general allegation that the other side hid information will not pause the 15-year clock. You need specific facts showing the concealment actually prevented you from discovering the claim.
• Reliable partial knowledge counts. You do not need to know every detail before the clock starts. If you had enough information to investigate and identify the potential claim, time was likely already running.
• Costs submissions matter. Courts must give parties a chance to address costs before making an order. If a judge skips that step, there may be grounds to appeal the costs decision alone.
• Get legal advice before filing. If your potential claim involves events from many years ago, a litigation lawyer can assess whether a limitation defence is likely before you invest in proceedings. Our Ontario litigation lawyers can help you evaluate your position.

If you are in the Hamilton or Burlington area and are concerned about whether a limitation period may affect your claim, speaking with counsel promptly is the most important step you can take. Our team serves clients throughout the region, including from our Burlington litigation office and our Hamilton litigation team.

UL Lawyers offers a free initial consultation from our Burlington office and serves clients across Ontario. If you have questions about limitation periods, civil claims, or whether a concealment argument could apply to your situation, contact our civil litigation team to get started.

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This article is automated commentary on a public court decision and is for general information only — not legal advice. Decisions rely on facts unique to each case. If you are affected by a similar issue, contact a lawyer for advice specific to your situation.