What happens if two people die at the same time in Ontario — whose estate gets what?

When two people die in the same accident or circumstances and it cannot be determined who died first, Ontario's Succession Law Reform Act provides a default rule: Ontario's Succession Law Reform Act provides a default rule: where it cannot be determined who survived whom, each person is treated as having survived the other for purposes of distributing their own property, so neither estate inherits from the other. This is sometimes called the "commorientes" rule.

The practical effect is that each spouse's estate is administered as though that spouse survived the other — so if two spouses die together and each left everything to the other, neither inherits from the other's estate. The gift to the spouse fails on both sides at once, and each estate instead passes to whatever alternate beneficiaries are named, or under the intestacy rules if there are none, regardless of which spouse was older.

Many well-drafted wills address this situation directly by including a survivorship clause — a requirement that a beneficiary must survive the testator by a certain period (commonly 30 days) to inherit. If the beneficiary does not survive the testator by that period, the gift lapses and passes to an alternate beneficiary or falls into the residue. This prevents the circular and potentially messy outcome where two estates inherit from each other in quick succession.

If you are updating your will, asking your lawyer about a survivorship clause is a sensible step, particularly if you and your primary beneficiary could conceivably die in the same event.