Social Insurance Number Usage
CAUTION when using Social Insurance Numbers.
Unless an employee has consented in writing for the specific use of his or her Social Insurance Number, the employer could face very substantial fines for improper use.
Generally speaking, unless a third party must use an employee's Social Insurance Number to report to either Revenue Canada, Human Resources and Skills Development Canada, or Revenue Quebec, an employer may not communicate the number to a third party.
For example, neither the Ontario Family Support Plan nor the British Columbia Family Maintenance Enforcement Program have the right to request an individual's Social Insurance Number from an Employer. A Bank or other Financial Institution also does not have the right to request the number when doing a credit check.
It was quite common in the past to use the employee's SIN as an employee number on their Canadian Payroll - this is prohibited. The SIN must not appear on pay cheques, pay advices or communicated to life insurance carriers, other benefit providers or to unions.