An insurer's appeal has failed at Ontario's top court after it could not show its policyholder breached the duty to cooperate.
In Monteith & Sutherland Limited v. Novex Insurance Company, 2026 ONCA 384, the Court of Appeal for Ontario dismissed Novex Insurance Company's appeal. A three-judge panel - Justices Grant Huscroft, J. Dawe and D.A. Wilson - heard and decided the matter orally on June 2, 2026, with the decision dated June 3, 2026. The reasons ran to five short paragraphs, and the three judges were unanimous.
The appeal targeted an August 15, 2025 judgment by Justice Charles C. Chang of the Superior Court of Justice, reported at 2025 ONSC 4697. The parties had agreed to proceed by application, on the footing that there was no dispute over the underlying facts. The appeal court found the application judge made no error in taking that path. Each of the insurer's grounds then came down to whether Justice Chang had erred - and on every one, the panel said he had not.
The first issue was the duty to cooperate, a standard condition in insurance policies. The panel saw no error in the application judge's finding that the policyholder did not breach it. It was open to him, the court said, to find there was "no substantial breach of the duty to cooperate." The judges anchored that conclusion in Ruddell v. Gore Mutual Insurance Company, 2019 ONCA 328, the authority they cited on the point.
The second issue was notice. The application judge had interpreted a curative provision - a clause that can excuse a technical defect in how notice is given - to permit notice to be delivered in the next policy period, as long as the insurer suffered no prejudice. The Court of Appeal found no error in that reading either.
For insurers and claims professionals, the decision rests on two familiar policy conditions. On the duty to cooperate, the court treated a substantial breach as the relevant threshold - and found none. On notice, the takeaway for claims teams is direct: where a policy contains a curative provision and the insurer cannot show prejudice, notice given in a later policy period can still hold. The court declined to disturb either of the application judge's findings.
With both grounds rejected, the appeal was dismissed, leaving Justice Chang's ruling in place. The court ordered Novex to pay the policyholder costs in the agreed amount of $79,100, all inclusive.
