Here I find this:
Ontario Statutes of Limitation
Since most debt actions are based in contract: 6 years from the date the cause of action arose (date of last payment or written acknowledgment of the debt).
NOTE: If the contract provides that the law of another jurisdiction governs it, the limitation period of that jurisdiction will apply.
The post-judgment enforcement remedy of filing a writ of seizure and sale provides that the writ is valid for 6 years from the date it is issued, subject to renewal, which is the responsibility of the creditor. A discretionary procedure exists to renew an expired writ.
Actions on foreign judgments, including those from the United States, must be commenced within 20 years from the date of the foreign judgment. The merits of the defenses, if any, which were raised in the foreign debt action, are generally not available as defenses to the action on the judgment.