Study permit is a document to certify that they are allowed to stay in Canada as a student. It includes the institution where the student is attending for school, the program, and the expiration date for studying in Canada, etc. If the study permit is expired, but is not being renewed, then the student must leave Canada. Otherwise, this is considered as a illegal stay, and it can result in their removal from Canada. Therefore, when students receive the student permit after entering in Canada, they must check the expiration date carefully, and make sure to apply for the renewal in time.