Social Insurance Numbers

I’ll start with some historical facts.  The SIN was created in 1964 to serve as a client account number in the administration of the Canada Pension Plan and Canada’s varied employment insurance programs. In 1967, what is now Canada Revenue Agency (CRA) started using the SIN for tax reporting purposes.  Basically, you need a SIN to work in Canada or to have access to government programs and benefits.

SINs are a nine-digit number.  The top of the card has changed over the years as the departments that are responsible for the card have changed:

  • Manpower and ImmigrationSIN (Iowa Lott)
  • Employment and Immigration Canada
  • Human Resources Development Canada
  • Government of Canada

As of 31 March 2014, Service Canada no longer issues plastic SIN cards.  Instead, an individual will receive a paper “Confirmation of SIN letter.”

For a list of list of legislated uses of the SIN, go here –


If you thought your SIN was arbitrary, think again.  The first digit of a SIN indicates the province of registration.

0 = Not used
1 = NB, NF, NS, PE
2 = QC
3 = QC
4 = ON
5 = ON
6 = AB, MB, SK, NT, NU
7 = BC, YU
8 = Not used
9 = Temporary

Temporary SINs

SINs that begin with a “9” are issued to temporary workers who are neither Canadian citizens nor permanent residents.  The use of these SINs is temporary and are valid only until the expiry date indicated on the immigration document authorizing them to work in Canada.  If your SIN begins with a “9”, you must update your SIN record to ensure that the expiry date always corresponds with the expiry date on your document from Immigration, Refugees and Citizenship Canada authorizing you to work in Canada.  Once your SIN record has been updated, you will receive a SIN with the new expiry date.  Your previous SIN is no longer valid and should be destroyed in a secure manner.

Validating your SIN:

First of all, no two people can have the same SIN.  Your SIN is unique to you, only!  That’s one reason why you should use your SIN, when having someone trustworthy, like me, check your credit report.  But that’s another subject for another day.

How can an online store tell when you have incorrectly entered your Visa number?  How does your income tax program know if you entered the wrong SIN?  Is it magic?  No, it’s a relatively simple checksum formula, known as Luhn algorithm.  It is used to validate a variety of identification numbers such as credit cards, and Canadian social insurance numbers.  It was created by IBM scientist Hans Peter Luhn.  Here’s how it works:

The 9 numbers above (Iowa Lott) are fictitious, but valid 324 217 694
Multiply each top number by the number below it 121 212 121

In the case of a two-digit number, add the digits together and insert the result. Thus, in the second-to-last column, 9 multiplied by 2 is equal to 18.  Add the digits (1 and 8) together (1 + 8 = 9) and insert the result (9).

So the result of the multiplication is:

344 415 694

Then, add all of the digits together:


If the SIN is valid, this number will be divisible by 10.

For more information about the Canadian SIN, visit the following FAQ:


If I can help, let me know.