Can one of several named co-executors renounce the role after already starting to act?

It's more complicated once someone has already started acting. Before doing anything — before collecting estate assets, dealing with the bank, or otherwise stepping into the role — a named executor can generally renounce cleanly and simply step aside. Once they've begun actively administering the estate, though, Ontario law treats that as having accepted the role, and a simple renunciation is generally no longer available.

At that point, the appropriate route is usually to apply to the court to be formally discharged or replaced as trustee, rather than simply walking away. The court will look at why the executor wants out, what's already been done, and what protections the estate needs during the handover to make sure nothing falls through the cracks — assets stay accounted for, and the remaining or incoming trustee has what they need to pick up where the departing one left off.

Anyone in this position — having accepted a co-executor role and now wanting out, whether because of the deadlock itself or personal circumstances — should get advice before taking any further action, since how the transition is handled affects both their own potential liability and the estate's ongoing administration.