What happens if a party doesn't show up to mandatory mediation in an Ontario estate dispute?

Failing to attend a mandatory mediation session in an Ontario estate dispute is taken seriously by the courts, because the requirement exists precisely to give every party a real chance to resolve the matter before trial. A party who simply doesn't show up, without a valid excuse or an order exempting them, can face cost consequences later in the litigation — a judge can order that party to personally pay some or all of the costs connected to the missed session, and can factor the non-attendance into the overall costs award at the end of the case.

Beyond costs, a pattern of ignoring mediation obligations can also affect how a judge views that party's conduct generally, which can influence discretionary decisions later in the proceeding. If you have a genuine reason you can't attend as scheduled — illness, an unavoidable conflict, or a real dispute about whether mediation should be excused in your situation — the better course is to raise it with the other side and, if necessary, bring it to the court's attention before the session, rather than simply not appearing. That keeps the option open to reschedule or seek an exemption instead of facing a costs order after the fact.