The CPA’s Social Insurance Number (SIN) Verification Tool was designed to help payroll
practitioners confirm if a SIN is valid. It cannot, however, confirm that a valid
SIN belongs to a specific individual.
Employers must ask to see the SIN card of all new employees and the employee must
show it within three days of starting employment.
A SIN is confidential and should only be used for statutory reporting purposes.
Under no circumstances should any documents bearing an individual’s SIN be left
exposed and unattended.