Temporary foreign workers and international students who are entitled to work in Canada often wonder how to match their work permits with the social insurance number (“SIN”) in order to keep using it.
The first thing to know is that the SIN is granted on a personal basis by Service Canada (SC) and that SC and Citizenship and Immigration Canada (CIC) are both federal agencies with different duties.
When someone is granted a SIN, this number will be the same for that person until they become permanent residents. Although, at the time of application, they are given a document that bears an expiry date, that is only a formality to serve as the first guidance for the right to use the SIN.
The SIN does NOT expire, what expires is the right to use it.
That being said, if someone is under implied status because they meet the conditions to keep working in Canada, they can continue to use the SIN despite the fact of having a document that says it is expired. It is not illegal to keep using the SIN as long as the applicant has the legal right to use it. That right is granted by the current immigration laws.