Social Insurance Number (SIN)

Definition

The Social Insurance Number (SIN) is a nine-digit identification number issued by the Government of Canada to Canadian citizens, permanent residents, and temporary residents who are eligible to work in Canada. 

What is a Social Insurance Number?

The primary purpose of the Social Insurance Number is to track individual earnings and contributions to Canada’s social security system. It also serves as a key identifier for tax purposes, facilitating the administration of income tax and other federal and provincial taxes.

The SIN is a nine-digit number in the format XXX-XXX-XXX, where each group of digits is separated by hyphens. The first digit of the SIN is always a digit between 1 and 9, while the remaining eight digits are randomly assigned.

The Social Insurance Number is a sensitive piece of personal information, and individuals are encouraged to safeguard their SIN and only provide it when necessary. Service Canada takes measures to protect the security and privacy of SINs and has implemented safeguards to prevent misuse or unauthorized access.

Individuals may need to update or replace their SIN card if it is lost, stolen, or damaged, or if their personal information changes. 

Example of a Social Insurance Number

A social insurance number (SIN) is a unique nine-digit number issued to individuals for purposes of identification and accessing government benefits and services. For example, John Smith might have a SIN of 123-456-789. This number is used for various purposes such as filing taxes, accessing government benefits like employment insurance or pension plans, and opening bank accounts.