Any company that is incorporated in Canada which wishes to carry on business in another province or territory other than the province or territory in which it is registered in most cases will need to be registered in that province to carry on business.

Each province and territory provides its own definition of what "carrying on business" means. It can be costly to register in another jurisdiction so you should ensure that you review the statute for the jurisdiction in which you wish to carry on business first to see if it will be necessary.