What happens if one of two named co-executors refuses to sign the probate application at all?

One uncooperative co-executor doesn't necessarily stop the estate from moving forward, but it does complicate things. Typically, the other named executor gives the reluctant co-executor formal notice of the intended application and a genuine opportunity to participate or to formally step aside. If that person still won't engage, the applying executor can look at proceeding with the application while making the court aware of the other named executor's status, rather than simply pretending they don't exist.

What happens next depends on the specific facts — whether the non-signing executor is actively refusing, has simply gone quiet, or is objecting to something specific about how the estate is being handled. A truly silent or unreachable co-executor is treated differently than one who is actively contesting the appointment, and the court has tools to address either situation, including directions on how the application should proceed.

Because getting this step wrong can delay the certificate of appointment for everyone, involving an Ontario estates lawyer as soon as one co-executor won't sign is worthwhile — they can advise on the right way to give notice, document the refusal, and frame the application so it isn't held up unnecessarily.