If you want to extend your stay in Canada as a visitor, you need to apply for a visitor record.

A visitor record is a document that continues to give you status as a visitor in Canada and allows you to stay longer. It will include a new expiry date. It does not guarantee that you can leave and then re-enter Canada. If you plan to travel outside Canada or the United States, you need a valid entry document, such as a visitor visa or eTA, to return to Canada.

You must apply for a visitor record before your current status expires.