Ontario's Limitations Act, 2002 sets a basic limitation period of two years to start most civil claims, running from the day you discovered — or reasonably ought to have discovered — the claim. There is also an ultimate limitation period of 15 years that is not subject to discoverability and runs from the date of the act or omission itself, regardless of when you found out. Missing either deadline generally bars the claim permanently.
- The basic limitation period is two years, running from discovery of the claim — not necessarily from the date of the underlying event.
- Discoverability means the clock starts when you knew, or reasonably ought to have known, the key facts giving rise to your claim.
- The ultimate limitation period is 15 years, running from the date of the act or omission itself, and applies regardless of when you actually discovered your loss.
- If you discover a loss in year 16, you are generally out of time, no matter how diligent you were.
- Some claims have different or shorter limitation periods under other statutes, so the two-year rule is not universal.
- Ongoing settlement negotiations do not automatically pause your limitation period.
The Basic Two-Year Period
Ontario's Limitations Act, 2002, in force since January 1, 2004, sets a basic limitation period of two years to start most civil claims. Missing this deadline is usually fatal — the other side can raise it as a complete defence, regardless of how strong the underlying claim otherwise is.
The Discoverability Rule
The two-year clock does not necessarily start on the date of the underlying event — it starts on the day you discovered, or reasonably ought to have discovered, the claim. This generally means the day you knew (or a reasonable person in your position ought to have known) that you suffered a loss, that it was caused by an act or omission of the other party, and that a legal proceeding was an appropriate way to seek a remedy.
A defect might not become apparent for months after it occurs; a financial loss might not be understood as connected to someone else's conduct until later. Discoverability accounts for this — but it requires a genuine, reasonable basis for the delay, not just a subjective claim of not knowing.
The Ultimate 15-Year Limit
Discoverability has an outer boundary. Ontario also imposes an ultimate limitation period of 15 years, which is not subject to discoverability and runs from the date of the act or omission itself — regardless of when the loss was actually discovered.
If you discover a loss more than 15 years after the underlying act or omission, you are generally barred from suing — no matter how diligent you were, and even if you genuinely could not have discovered the claim any sooner.
| Period | Length | Subject to Discoverability? |
|---|---|---|
| Basic limitation period | 2 years | Yes — runs from discovery |
| Ultimate limitation period | 15 years | No — runs from the act or omission itself |
Exceptions and Other Statutes
Not every claim follows the general two-year rule. Some specific claim types are governed by different limitation periods set out in other legislation, and certain circumstances — including claims involving minors or parties under a legal disability — can affect when a limitation period begins to run. We confirm the specific limitation period that applies to your exact type of claim rather than assuming the general rule automatically governs.
Why This Matters Practically
Ongoing settlement discussions do not automatically pause your limitation period. Parties can occasionally agree to a formal tolling agreement suspending the clock while they negotiate, but absent that, continuing to negotiate informally as a deadline approaches carries real risk. This applies across every type of civil claim — from a breach of contract to a negligence claim to an estate litigation matter.
A business discovers a supplier substituted lower-quality materials into a project completed 18 months earlier, only realizing the cause of subsequent defects after an inspection. Because the claim was only reasonably discoverable at the time of the inspection — not at the original completion date — the two-year clock is calculated from that later discovery date.
What to Do If You Are Unsure
If you suspect you may have a claim — even one that has been sitting unresolved for a while — get advice promptly rather than assuming it is either too late or that there is no rush. We can quickly confirm where your limitation period stands and, where needed, file protectively to preserve your rights while other options are explored.
Call our Ontario civil litigation lawyers at 416-274-2222 to confirm where your claim stands.
Frequently Asked Questions
Generally two years from the day you discovered, or reasonably ought to have discovered, the claim — under the Limitations Act, 2002. This is the "basic" limitation period that applies to most civil claims, though some claim types have different rules under other statutes.
It means the two-year clock does not necessarily start on the date of the underlying event — it starts when you knew, or a reasonable person in your circumstances ought to have known, the key facts: that you suffered a loss, that it was caused by the other party's act or omission, and that a legal proceeding is an appropriate remedy.
Yes — Ontario also has an ultimate limitation period of 15 years, which runs from the date of the act or omission itself and is not affected by discoverability. If you discover a loss more than 15 years after it happened, you are generally out of time regardless of the circumstances.
No — some specific claim types are governed by different limitation periods under other legislation. It is always worth confirming which limitation period applies to your specific type of claim rather than assuming the general two-year rule automatically governs.
Not automatically. Ongoing settlement discussions do not, by themselves, extend or pause your limitation period. In some cases parties can sign a formal tolling agreement, but absent that, it is prudent to file protectively if a deadline is approaching, even while negotiations continue.
The claim is generally barred entirely — the other side can raise the expired limitation period as a complete defence, regardless of how strong your claim would otherwise have been. This makes early legal advice important as soon as you suspect you may have a claim.