Can I sue my insurer if they deny my business interruption claim in Ontario?

Yes, a denied business interruption claim can be pursued as a breach of contract claim like any other coverage dispute, but these claims have some specific features worth understanding first. Business interruption coverage typically only responds once a covered triggering event - most commonly direct physical damage to your property from an insured peril - has actually occurred; it generally isn't a standalone policy covering any loss of income for any reason. A common ground for denial is that the insurer says no qualifying triggering event happened, or that the interruption isn't sufficiently connected to the physical loss that did occur.

Where a claim is accepted in principle, disputes often shift to calculating the loss itself: what income would have been earned during the interruption period, how long the "period of restoration" should reasonably run, and what ongoing expenses continue regardless of the interruption. Because these calculations depend heavily on financial records and reasonable projections rather than a fixed formula, an insurer's own damage calculation is often the real point of disagreement, not whether coverage exists at all - so financial documentation supporting your own figures is essential to challenging a low valuation or an outright denial.