Social Insurance Number
You must have a social insurance number when you complete your income tax return. The social insurance number is a confidential nine-digit personal identification number that is assigned by the federal government to all persons residing in Canada, whether they are newcomers or not.
Since no two social insurance numbers are the same, Revenu Québec uses your social insurance number to identify you, in particular with regard to income tax and benefits. For example, we use your social insurance number when we transmit the amount of your earnings as an employee or a self-employed person to Retraite Québec.
If you do not have a social insurance number, you can apply for one at the Service Canada office in your area.