If I have two insurance policies covering the same loss, how is the dispute between insurers resolved in Ontario?

When two policies both potentially cover the same loss, most policies include an "other insurance" clause addressing how they interact - some are excess to other coverage, some prorate the loss based on relative policy limits, and some simply share liability equally. How these clauses interact between your two specific insurers determines who ultimately pays what share, and disagreements between the insurers about how their respective clauses should be read are common.

Importantly, this is generally a dispute between the insurers, not something that should leave you, the insured, unpaid while it gets sorted out. You can typically look to either insurer for payment of your covered loss, and it then becomes that insurer's responsibility to seek contribution from the other insurer for its fair share. If an insurer tries to deny or delay your claim entirely on the basis that "the other policy should pay first," it's worth pushing back, since the usual approach lets you collect from either covering insurer while they resolve the allocation between themselves separately.