In order to work in Canada, you must have a Social Insurance Number (SIN). Your SIN is confidential and must be protected. Your SIN is linked to numerous government benefits - if someone else get a hold of your SIN, they can receive your rightful government benefits, services, or tax refunds.
If my SIN is so important, why do many employers ask for it right away?
It is not against the law for employers to ask for your SIN. Most employers ask for your SIN to conduct credit checks as part of the background screening process. In fact, within three days after your employment begins, employers are required by law to request your SIN.
Having your SIN on file, allows employers to provide information to the government regarding your income, income tax deducted, and amounts related to government benefit programs, like unemployment insurance or pension. Employers also need your SIN so they can provide you with your Record of Employment (ROE) or your T4 for income tax.
Do I need to provide my SIN to my employer?
As an individual, you do not have to provide your SIN unless deemed necessary by the government. If you are unsure about whether or not you should provide your SIN, feel free to ask! Under the Personal Information Protection and Electronic Documents Act (PIPEDA), you have the right to know why and how an organization will collect, use, and disclose your information.