To find out whether a person who is presumed to be incapable has an incapacity mandate, you may ask your notary or attorney to conduct a search.
You may also take care of this yourself, by applying directly to the Québec registers of wills and mandates (Registres des dispositions testamentaires et des mandats). You must fill out an application form and enclose the required documents. As soon as it receives the documents, the Chambre des notaires du Québec will send you the required certificate of search. If the search has been fruitful, the name of the notary or attorney who registered the incapacity mandate will appear on the certificate.