Social Insurance Number
Overview
 
A social insurance number (SIN) is a number issued in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 to administer various government programs. The SIN was created in 1964 to serve as a client account number in the administration of the Canada Pension Plan
Canada Pension Plan
The Canada Pension Plan is a contributory, earnings-related social insurance program. It forms one of the two major components of Canada's public retirement income system, the other component being Old Age Security...

 and Canada's varied employment insurance programs. In 1967, Revenue Canada (now the Canada Revenue Agency
Canada Revenue Agency
The Canada Revenue Agency is a federal agency that administers tax laws for the Government of Canada and for most provinces and territories, international trade legislation, and various social and economic benefit and incentive programs delivered through the tax system...

) started using the SIN for tax reporting purposes. SINs are issued by Human Resources and Social Development Canada (previously Human Resources Development Canada).

The SIN is formatted as three groups of three digits (e.g., 123-456-789).
Through functionality creep, the SIN has become a national identification number
National identification number
A national identification number, national identity number, or national insurance number is used by the governments of many countries as a means of tracking their citizens, permanent residents, and temporary residents for the purposes of work, taxation, government benefits, health care, and other...

, in much the same way that the Social Security Number has in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.
 
x
OK