How long do I have to sue for breach of contract in Ontario?

In Ontario, the standard limitation period for a breach of contract claim is two years from the date of discovery under the Limitations Act, 2002. Discovery typically means the date you knew or ought to have known that the contract was breached, that the breach caused you a loss, and that the party who breached it is identifiable.

For many straightforward breaches — a contractor who fails to complete work on a specific date, a buyer who does not pay on closing — discovery happens close to the date of the breach itself. In more complex commercial arrangements, especially where a breach is concealed or only becomes apparent over time, the discovery date may be later than the technical breach date.

The 15-year ultimate limitation period also applies: even if you only discovered the breach much later, you cannot sue more than 15 years after the act or omission that gave rise to the claim. Ontario courts take limitation defences seriously. Defending a claim on limitations grounds is a cost-effective way to dispose of stale litigation, so defendants in breach of contract cases frequently raise it. If you believe you have a contract claim, speak with a lawyer promptly and do not delay starting your action on the assumption that informal negotiations will preserve your rights — they generally do not stop the clock.