The most common method of filing bankruptcy is for you to file an Assignment In bankruptcy.
You choose your Trustee to act in your Assignment. You choose the filing date, at which time all the documents are signed. Your Trustee delivers some of your signed documents to the Official Receiver who works for the Federal Government in the Office of the Superintendent of Bankruptcy.
It is the Official Receiver who appoints your Trustee for your bankruptcy, based on your Assignment document. The appointment of your Trustee is classified as a Court appointment.
Your date of bankruptcy, in an Assignment, is the date your Trustee files your Assignment document with the Official Receiver.
You should note that although you choose your Trustee, your Trustee does not work for you. Your Trustee is licensed by the Office of the Superintendent of Bankruptcy to administer bankrupt estates under the provisions of the Bankruptcy and Insolvency Act in Canada. Your Trustee In Bankruptcy is an independent Officer of the Court.