A Social Insurance Number (SIN) is a unique nine-digit number that is used to identify individuals for tax and other government-related purposes in Canada. It is important for individuals who are working in Canada or receiving benefits from the government to have a SIN.
The SIN program was introduced in 1964 to help the government track and manage tax deductions and payments. Over the years, the SIN has become an important part of the Canadian identity system and is used for a variety of purposes, including: