Where an estate trustee, on behalf of an estate, wishes to initiate an action against a third party, or where a third party wishes to sue an estate, a Certificate of Appointment of Estate Trustee is necessary.  Professor Oosterhoof (in Oosterhoof on Wills and Succession) explains:

The grant of probate is only evidence (really, the only evidence) which a court will recognize that a person has authority to administer the assets of the deceased. For this reason, while an executor can do many acts of office before obtaining a grant he or she cannot obtain judgment before that time, although he or she can commence an action. Similarly, no action can be maintained against a named executor unless he or she has obtained a grant of probate.

This position was supported by the Ontario Court of Appeal in Re Eurig Estate 1997), 31 O.R. (3d) 777 (C.A.) (reversed on other grounds, [1998] 2 S.C.R. 565):

Further, apart from the general legal duty to administer the estate promptly and efficiently, which almost invariably requires the executor to obtain probate, the law imposes the requirement that an executor must have probate to prove his or her title when an estate matter is before the court. Letters probate are the only evidence of an executor’s title which a court will receive (see Hull and Hull, Macdonnell, Sheard and Hull, Probate Practice, 4th ed. (1996) at pp.185 and 188), even in a case where the defendant is willing to concede that the executor has title without evidence of probate: Re Crowhurst Park; Sims-Hilditch v. Simmons, [1974] 1 W.L.R. 583 (Ch), (at p. 792).

In the event that no Certificate of Appointment of Estate Trustee is obtained, the Rules of Civil Procedure, contains a remedial provision to correct an improperly commenced action.

9.03 (1) Where a proceeding is commenced by or against a person as executor or administrator before a grant of probate or administration has been made and the person subsequently receives a grant of probate or administration, the proceeding shall be deemed to have been properly constituted from its commencement.

The Rules of Civil Procedure also provide for a claimant to have a party appointed as litigation administrator in order to defend a lawsuit against the estate where no Certificate of Appointment of Estate Trustee has been issued.

9.02(1) Where it is sought to commence or continue a proceeding against the estate of a deceased person who has no executor or administrator, the court on motion may appoint a litigation administrator to represent the estate for the purposes of the proceeding.

Thanks for reading,

David Morgan Smith