International Students

Social insurance number (SIN)

what is a social insurance number (sin)?

A SIN is a unique 9-digit number, issued free of charge by Service Canada.  International students who would like to work in Canada must obtain a SIN, which is needed for tax purposes. 

You will be required to provide this number to your future employer, once your employment has been confirmed and you might also need to share it upon registering with some service providers (ex: Hydro-Québec, phone companies).  Students registered in a research-based program who are receiving financial assistance from their supervisor also need to provide it to Polytechnique, in order to receive payments.  It’s important to keep your SIN number confidential and to provide it only when necessary.

Your social insurance number will be valid until your study permit expires.  Should you need to renew your study permit in order to finish your program, you will also need to extend your SIN after receiving your new study permit.  

For more information about social insurance numbers, visit this Government of Canada website or go to a Service Canada office in person.


There are various ways to apply to SIN: online, by mail and in person at a Service Canada office.  It can also be obtained at the airport on arrival, according to certain timetables.

To apply, you will need to provide copies of several documents, including:

  • A study permit that indicates that you are authorized to work on and off campus.  If this remark is not on your study permit (SP) or if the SP indicates that you are not authorized to work, you will not be able to obtain a SIN.  You will rather need to follow the indications on this document.  
    a work permit (e.i. co-op work permit)
  • Passport

More details on how to apply for a SIN 

study permit renewals and transition to worker status

If you are a graduand or a student renewing your study permit, you must request a SIN extension as soon as your receive your post-graduation work permit (PGWP) or new SP. In both cases, the number will remain the same, and you will be allowed to maintain work or start a new job while waiting to extend your SIN.  If your SIN expires before you receive your document and are employed or soon-to-be employed, you may want to direct your employer to the Government of Canada’s explanation of “implied status”