Canadian SIN: Who Qualifies, Documents Needed, and How to Apply

To apply for a Canadian SIN, submit a free application to Service Canada with an original identity document that matches your status in Canada. You can apply online, in person at a Service Canada Centre, or by mail. There is no fee, the number is yours for life, and you’ll receive a paper Confirmation of SIN letter rather than a plastic card.¹

Who Can Apply

Three groups qualify: Canadian citizens, permanent residents, and temporary residents authorized to work or study in Canada.²

Citizens and permanent residents get a SIN with no expiry date. Temporary residents receive a SIN that begins with the digit 9 and expires on the same date as their work permit, study permit, or visitor record.³

Children qualify too. Anyone 12 or older can apply for themselves, and a parent or legal guardian can apply for a child who is under the age of majority in their province.² For newborns, most provinces let you apply at the same time you register the birth through the Newborn Registration Service. In the territories, you apply through Service Canada directly.⁴

Documents You Need

Mail and in-person applications require original documents. Photocopies aren’t accepted. Online applicants upload digital copies of those same originals.⁵

Primary Identity Document

Your primary document proves both identity and legal status. What you provide depends on your status:

Canadian citizens born in Canada: a birth certificate issued by the vital statistics agency in your province or territory of birth.
Canadian citizens born abroad: a Certificate of Canadian Citizenship or Certificate of Registration of Birth Abroad, both issued by Immigration, Refugees and Citizenship Canada (IRCC).
Permanent residents: a Permanent Resident Card issued by IRCC, or a Confirmation of Permanent Residence (accepted within one year of becoming a permanent resident; after that, the card is required).
Temporary residents: a work permit, a study permit indicating you’re authorized to work in Canada, or a visitor record authorizing work, all issued by IRCC.

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Secondary and Supporting Documents

If you apply in person and have reached the age of majority in your province, you’ll also need an original secondary identity document, such as a valid passport or driver’s license. If the name on any of your documents doesn’t match the name on your application, include a supporting document that explains the change, such as a marriage certificate or court order.⁶

The application (form NAS 2120) asks for your full legal name, date of birth, place of birth, your mother’s surname at birth, and your father’s first given name. Mistakes in these fields cause delays or rejections, so check each entry against your documents before you submit.

Three Ways to Apply

All three methods cost nothing. The difference is speed and how you send your documents.

Online

Applying through the Service Canada online portal is the fastest option. You upload digital copies of your original documents and submit the form electronically. If your application is complete, you’ll receive your SIN within five business days, followed by a confirmation letter by mail.⁷

In Person

Bring your original documents to any Service Canada Centre. If everything is in order, you’ll walk out with your SIN and your documents at the end of the appointment.⁶ This is the best route if you need to start work right away.

By Mail

Send the completed application and your original documents to:

Service Canada
Social Insurance Registration Office
P.O. Box 7000
Bathurst, New Brunswick E2A 4T1
Canada

Processing takes up to 20 business days from the date Service Canada receives a complete application, and your originals come back by mail.⁷ Since irreplaceable documents travel through the postal system either way, most applicants pick online or in person when they have the choice.

Whichever method you use, plastic SIN cards are no longer issued. Your official record is the paper Confirmation of SIN letter.¹

Renewing a Temporary SIN

If you’re a temporary resident and IRCC extends your work or study permit, the expiry date on your SIN needs to be updated to match. To do that, submit a new SIN application with your renewed immigration documents using any of the three methods above. Once processed, you’ll get a new Confirmation of SIN letter, or an email notification, showing the updated expiry date.⁸

What if your permit expires while IRCC is still processing your extension? Under maintained status, you can keep working even if your SIN has technically expired, as long as you applied for the permit extension before the old one ran out. Maintained status lasts until IRCC makes a decision on your application.⁸

Replacing a Lost SIN or Updating Your Record

If you’ve lost your Confirmation of SIN letter or can’t remember the number, you can request a new confirmation using the same application process as a first-time SIN. Service Canada will confirm your existing number rather than assign a new one.¹

If your legal name changes through marriage, divorce, or court order, or there’s an error in your date of birth or parents’ names on file, you update your record the same way: submit the application form and the documents that prove the change, online, in person, or by mail.⁹ Your SIN itself stays the same; Service Canada corrects the information tied to it.

When You Don’t Need to Give Out Your SIN

Once you have a SIN, it’s worth knowing that it isn’t a general-purpose ID. Your employer needs it for payroll and T4 slips, and you must provide it within three days of starting work.¹⁰ Banks collect it for accounts that earn income, because they have to report that income to the Canada Revenue Agency.¹¹ Outside those employment, tax, and benefit purposes, most requests are optional. Landlords, telecom providers, car rental companies, post-secondary schools, and employers screening job applications do not need your SIN, and neither does a routine credit check or credit card application. If someone asks and can’t point to a law that requires it, you can decline.

1
Government of Canada. Social Insurance Number – Overview
2
Government of Canada. Social Insurance Number – Do You Qualify
3
Government of Canada. Social Insurance Number for Temporary Residents in Canada
4
Government of Canada. Register Your Child’s Birth
5
Government of Canada. Social Insurance Number – Required Documents
6
Service Canada. Application for a Social Insurance Number Information Guide
7
Government of Canada. Social Insurance Number Application
8
Government of Canada. Social Insurance Number – Receiving and Updating Your SIN
9
Government of Canada. Apply, Update or Obtain a SIN Confirmation
10
Government of Canada. The Social Insurance Number (SIN) Code of Practice
11
Government of Canada. Social Insurance Number (SIN)