What is a caveat and how does it stop probate in Ontario?

A caveat is a formal legal notice filed with the Ontario Superior Court (Estates) that prevents the court from issuing a Certificate of Appointment of Estate Trustee (commonly called probate) without first notifying the person who filed the caveat. It is a tool used by people who have concerns about a will's validity or an estate administration, and who need time to investigate or take legal action before assets start flowing out of the estate.

When a caveat is filed, the court places it on the record. If someone then applies for probate, the court notifies the caveator before proceeding. This gives the caveator an opportunity to bring their challenge before the certificate is issued. Once probate is granted and assets are distributed, recovering those assets becomes very difficult, so a caveat can be a critical protective step.

A caveat is not a permanent stop — it must be renewed periodically and is not a substitute for actually bringing a legal challenge. Filing a caveat without a genuine basis for doing so, purely as a delay tactic, can expose the caveator to a costs award.

If you suspect a will is invalid, that there is undue influence, or that an executor is acting improperly before probate is granted, speaking with an estate litigation lawyer about filing a caveat is one of the first steps to consider.