You usually need a work permit to work in Canada.
There are two types of work permits:
1) Open work permits
2) Employer-specific work permits.
If you want to extend your stay in Canada as a worker, check the expiry date on your work permit, and make sure you apply before that date. Complete the Application to Change Conditions or Extend Your Stay in Canada at least 30 days before your current permit expires.
If your job is extended or changes, you must apply to extend or change the conditions of your existing work permit before it expires.
If you are offered a different job in Canada, you must apply for a new work permit.
Do not start your new job without a new work permit.
A work permit lets you work in Canada temporarily.
If you want to stay in Canada permanently, you must qualify under one of the permanent resident categories. Learn about the permanent resident categories.
If you have lost your work status and you are still in Canada that means you didn’t respect the conditions of your permit.
In some cases, you may apply to restore your status. To apply, you must apply within 90 days of losing your status.
Give details of your situation and the reason you stayed in Canada longer than allowed. There is no guarantee that your application would be accepted.
You may stay in Canada while a decision on your application is pending. But, you aren’t allowed to work until your status has been restored. An officer will review your application and tell you what else you need to do.
In some categories, you can work without a permit with terms and conditions laid by the govt. of Canada.
Athlete or coach, Aviation accident or incident investigator, Business visitor, Civil aviation inspector, Clergy, Convention organizer, Crew member, Emergency service provider, Examiner and evaluator, Expert witness or investigator, Family member of foreign representative, Foreign government officer or representative, Health care student, Judge, referee or similar official, Military personnel, News reporter or film and media crew, Producer or staff member working on advertisements, Performing artist, Public speaker, Short-term highly-skilled worker, Short-term researcher, Student working off-campus, Student working on-campus.