For many civil claims in Ontario, the basic limitation period is two years from the date the claim was discovered. That does not always mean two years from the date of the underlying event. Under Ontario’s Limitations Act, 2002, determining when a claim was discovered can require a fact-specific analysis of what the claimant knew — or reasonably ought to have known — and when a legal proceeding became an appropriate means of seeking a remedy.
Commencing a proceeding after the applicable deadline can result in an otherwise viable claim being barred, so limitation analysis should be addressed early.
For the broader process once a civil proceeding is commenced, see What is civil litigation in Ontario?.
Scenario 1 — The loss and potential claim are immediately apparent
In a relatively straightforward case — for example, where a contractual breach, non-payment, or other loss is immediately known — the discovery date may be close to the date of the underlying event.
Section 4 of the Limitations Act, 2002 provides the basic rule: unless the Act provides otherwise, a proceeding cannot be commenced more than two years after the claim was discovered.
Parties should therefore not assume that prolonged negotiation or correspondence automatically preserves the right to commence a claim.
Scenario 2 — The claim is discovered later
Some losses are not immediately identifiable.
Under section 5, discovery depends on when the claimant knew, or a reasonable person in the claimant’s circumstances ought to have known, that:
- injury, loss, or damage had occurred;
- an act or omission caused or contributed to it;
- the act or omission was attributable to the proposed defendant; and
- having regard to the nature of the loss, a proceeding was an appropriate means to seek a remedy.
That discoverability analysis can be important in disputes involving concealed conduct, developing losses, complex transactions, or facts that become clear only after further information is obtained.
If you are still identifying the nature of the underlying dispute, see What types of disputes are considered civil litigation in Ontario?.
Scenario 3 — The claim is very old
Ontario also has an ultimate limitation period.
Section 15 of the Limitations Act generally prevents a proceeding from being commenced more than 15 years after the act or omission on which the claim is based, even where the ordinary discovery analysis might otherwise produce a later date. The Act contains statutory exceptions and periods during which the ultimate limitation period does not run.
The 15-year period should not be treated as an alternative deadline that allows a claimant simply to wait.
Are all Ontario claims subject to the same limitation period?
No.
The Limitations Act itself excludes certain proceedings from its general regime, including matters governed by the Real Property Limitations Act, and section 16 identifies specified proceedings for which no limitation period applies.
The Act also contains special provisions concerning minors, incapable persons, acknowledgments, contribution and indemnity claims, and agreements affecting limitation periods. Other legislation may impose its own deadlines or notice requirements.
Limitation analysis should therefore be based on the actual facts and legal basis of the proposed claim rather than assuming every Ontario dispute has a simple two-year deadline.
ME Law assesses limitation issues together with the underlying causes of action, available evidence, procedural posture, and remedies being sought. Where a potential deadline is approaching, it may be necessary to determine promptly whether a proceeding should be commenced to preserve the claim.
For information about defending an existing proceeding, see Defending a Civil Claim.
Contact ME Law if you are concerned that a limitation period may affect a civil claim.