How long after a death do I have to start a dependant's support claim against an Ontario estate?

You generally have six months from the date the court issues the estate trustee's Certificate of Appointment of Estate Trustee — commonly called a grant of probate, or letters of administration where there's no will — to bring a dependant's support claim under Part V of the Succession Law Reform Act (SLRA). That clock runs from the certificate itself, not from the date of death, so the real deadline depends on how quickly the estate trustee applies for and receives it.

Missing this window isn't automatically fatal. Ontario courts have discretion under SLRA s.61(2) to let a claim proceed later, but only against whatever part of the estate hasn't already been distributed to beneficiaries — so delay can shrink or eliminate what's actually available to claim against. Because the trigger date is a court filing you may not see happen, and because assets can move quickly once a certificate issues, anyone considering a dependant support claim should get legal advice as soon as possible after the death rather than waiting to see how things unfold.