Your SIN is a confidential number that is restricted to income reporting purposes. There are a select and limited number of federal government departments and programs specifically authorized to collect the SIN.
When it comes to what you can do when asked for your SIN by some agency other than the feds, the Privacy Commissioner offers the following advice:
- Ask if you are required by law to provide it (see list below);
- Ask why the person needs it, how it will be used and to whom it will be given;
- Your SIN is not a piece of identification. If it is not required by law (and you are not satisfied with the explanation), tell the person you prefer not to use the SIN and offer other identification;
- If the organization refuses to give you the product or service unless you give your SIN, complain to the Privacy Commissioner of Canada;
- If you would like better legal protection for your SIN, call or write your federal Member of Parliament.
More information on authorized uses of your SIN can be found here. Know your rights.