Anyone who moves to Canada to work needs a Social Insurance Number, usually called a SIN. It is the number employers, banks and government departments use to identify you, and without it you cannot legally be paid.
The SIN is what connects you to the tax system and to federal programmes. Whether you are starting a job, claiming Employment Insurance or building entitlement to a pension, the number has to be on file.
Getting one is straightforward, but the documents, the timing and the rules on updating a SIN catch people out, particularly temporary residents whose number expires. This guide covers who needs a SIN, how to apply, how to protect it and what to do when your status changes.
What is a SIN number in Canada?
If you intend to work in Canada or use federal services, you need a Social Insurance Number. It is a nine-digit number, and it is one of the first things an employer will ask for when you start work, get paid and begin filing tax.
The SIN lets the federal government link your employment record, your tax filings and your access to benefit programmes to one identity. Anyone working in Canada or drawing on federal programmes needs one.
Who needs a SIN number in Canada?
Anyone who works in Canada or receives government benefits needs a SIN. That covers:
- Canadian citizens
- Permanent residents
- Temporary residents who are authorised to work or to access government services
The SIN identifies you in federal and tax systems and is a precondition for working in Canada.
SIN numbers for children
A child aged 12 or over can apply for a SIN in their own name. For a child below the age of majority in their province, which is 18 or 19 depending on where they live, a parent, legal guardian or legal representative can apply on their behalf. The same applies to an adult under someone else’s legal care.
If you or your child need a SIN, you can apply through the Government of Canada website or in person at a Service Canada office.
Which application type applies to you?
The first step is identifying which situation you are in, because that determines the documents required. Service Canada sets out several scenarios, and picking the right one at the start avoids a rejected or delayed application.
1. Applying for yourself
This covers people applying on their own behalf: international students, newcomers and anyone who has just started work in Canada.
2. Applying as a parent or legal guardian for a child or dependant
A parent, guardian or legal caregiver applies for a child below the age of majority, or for an adult in their care. The age of majority differs by province and is either 18 or 19.
3. Applying as someone’s legal representative
Where a person cannot apply themselves for physical, cognitive or legal reasons, their legal representative can apply. Documents proving the representative’s authority have to be supplied.
4. Applying as the legal representative of a person who has died
If you are dealing with the financial or legal affairs of someone who has died, you can request confirmation of their SIN. This is normally needed for estate administration, probate and closing financial records.
Each scenario has its own document list. Getting the category right at the outset means you assemble the right documents once. The current list is published on the Social Insurance Number pages of the Government of Canada website.
Protecting your SIN number
Your SIN is among the most sensitive pieces of personal information you hold in Canada. It is needed for work and for benefits, and in the wrong hands it can do real damage. Here is why protecting it matters.
- Identity theft and loss of privacy
If your SIN reaches someone who intends to misuse it, it can be used for financial fraud or to file false information in your name. That damages your credit record and can leave you answering for activity you had nothing to do with.
- Loss of money or benefits
Misuse of a SIN can cost you government benefits, a tax refund or access to credit. People have discovered accounts opened and benefit payments claimed in their name without their knowledge.
- Tax problems
If someone works illegally using your SIN, you can end up assessed for tax on income you never earned. Unwinding that with the Canada Revenue Agency (CRA) takes time and paperwork.
How to apply for a SIN number in Canada
The Social Insurance Number is what makes legal employment and access to federal programmes possible. If you have just arrived in Canada, the method and the documents depend on your situation. There are three ways to apply.
- Online
- In person at a Service Canada office
- By mail
Applying online is normally the fastest route if you are not going in person.
- With a complete form and the required documents, an online application is usually processed within about five business days, and the number is then available in your My Service Canada account. Service Canada revises its service standards, so treat any published timeline as indicative.
- You can only apply once you hold a valid document authorising you to be in Canada, such as a work permit or a study permit.
Without that document there is nothing to apply on. For the current requirements and forms, use the Government of Canada website.
Updating your SIN record
To change the information attached to your SIN, you submit a new application with supporting documents. Once the change is processed you receive a letter or email confirming that the record has been updated.
A SIN normally stays the same for life. The exception is a change of immigration status. Temporary residents are issued a SIN beginning with the digit 9, and that number carries an expiry date tied to the permit that authorises the work.
If your status changes and you are issued a new SIN, the main federal departments are updated automatically, but you have to tell your employer, your bank and anyone else who holds the old number.
Do you also need work authorisation?
Holding a valid SIN does not by itself give you the right to work in Canada. The permission to work comes from your immigration status, not from the number.
Full-time students at a designated learning institution in an eligible programme can generally work off campus under the conditions printed on the study permit, without a separate work permit. Eligible full-time students may work up to 24 hours a week off campus during regular school terms, and unlimited hours during breaks scheduled by their school. Working more than 24 hours a week during term breaches the study permit conditions. If your study permit carries the condition “This permit does not permit the holder to engage in off-campus employment in Canada”, you are not authorised to work off campus at all.
If the conditions on your permit are unclear, speak to the international student advising office at your institution before you accept work. Working outside the conditions of a permit can affect a future extension and a later permanent residence application.
Expiry, misuse and security
A SIN beginning with 9 expires on the same date as the permit that authorises you to work in Canada. Every time you extend a study or work permit and intend to keep working or to file tax, you have to update your SIN record with the new document.
The SIN is sensitive personal information and the federal government treats misuse of it seriously.
If you think someone has used your SIN without permission, or you have been told your information was exposed in a data breach, act quickly to limit the damage.
Signs that a SIN is being misused include:
- A notice from the Canada Revenue Agency (CRA) about income you never reported, which can mean someone earned money using your number.
- Transactions or credit applications you do not recognise on your credit report.
- Employment records you do not recognise in your My Service Canada account.
If you see any of these, report it and take steps to secure your records straight away.
Frequently asked questions
1. Can you apply for a SIN from outside Canada?
Yes. If you are outside Canada but hold a valid study or work permit, you can apply online for a new SIN, update your record or request confirmation of an existing number, even without a Canadian mailing address. You supply a copy of your passport and of the permit.
2. What is the fastest way to get a SIN in Canada?
Going in person to a Service Canada office is the quickest route, since the number is normally issued during the visit.
Online applications are usually processed within about five business days, and a mailed confirmation takes longer. Service standards change, so check the current published times.
3. Does your SIN change when you become a permanent resident?
Yes. Once you receive Canadian permanent residence you apply for a new SIN, selecting Change of Status as the application type. The new number will not begin with 9 and does not carry an expiry date.
