At one point in your life, you may have heard someone tell you to not lose your Social Insurance Number (SIN), at all costs. If it got stolen or you think you lost yours, there’s nothing to worry about. It’ll be okay. 

Here’s what you need to know about why your SIN is important, what to do if it’s lost or stolen, and how to protect it.

Key Takeaways
  1. Find your SIN on a card, a confirmation letter, or CRA-related tax forms such as income tax returns, tax slips, records of employment, and RRSP contribution documents.
  2. You can apply for a reissued version of your SIN confirmation letter for free.
  3. The only time Service Canada will replace your SIN is if there’s proof that you’re a victim of identity theft or fraud.

What is a Social Insurance Number (SIN)?

Commonly referred to as a “SIN number”, your SIN is a 9-digit number that Service Canada gives you as a citizen, permanent resident, or temporary resident. 

Every person has their own unique SIN. It’s what you need to work in Canada, file your income tax returns, or access government programs and benefits like collecting tax credits.

Your parents or legal guardians may have applied for your SIN when you were born. Otherwise, you likely got yours as a teenager, before you started your first job. 

Where can I find my Social Insurance Number (SIN)?

You don’t have to look hard. Your 9-digit SIN is in one of two places.

  • SIN card or confirmation letter: Service Canada issues out our SIN in a paper format called, Confirmation of SIN letter. If you have a physical card that hasn’t expired, it’s still valid.
  • CRA documents: The Canada Revenue Agency (CRA) uses your SIN to identify who you are, so check the first page of any CRA-related tax forms such as income tax returns, tax slips, records of employment, and RRSP contribution documents.

Can I get a replacement if I’ve lost my SIN?

It happens. People lose or have their Social Insurance Numbers stolen. But not to worry. SIN replacement isn’t difficult. Service Canada can reissue your SIN confirmation letter for free if you apply.

  • In person: Visit your local Service Canada branch with the required information that proves your identity, status, and proof of address. You’ll get a reissued version of your SIN confirmation letter on the spot.
  • Online: Submit an application through Service Canada depending on your situation and status in Canada.
  • Mail: Complete, sign, and mail the SIN application form along with the required documents. Service Canada will mail your SIN confirmation letter. But, before mailing your SIN request, you must first get permission from Service Canada by calling 1-800-206-7218 (select Option #3).

What to do if your SIN gets stolen?

In the unfortunate event of identity theft or fraud, you’ll be issued a new SIN. Check out Service Canada’s protecting your Social Insurance Number web page for more details.

To be on the safe side, review your bank account, credit cards, and other financial transaction statements. If anything doesn’t look right, promptly contact your bank. If you suspect that your SIN is being used fraudulently, report this to the police. It’s a serious matter.

Also, know your do’s and don’ts of safely filing taxes online.

How to protect your SIN number?

Your SIN is confidential and it’s illegal for anyone else to use it. So it’s important you protect it and keep it in a safe and secure place that won’t get easily stolen or lost. Otherwise, it could lead to invasion of privacy, identity theft, credit fraud, or you losing government benefits, tax refunds, or bank credits.

When to give out your SIN number?

When to share your SIN

When to NOT share your SIN

  • After being hired by your employer
  • When it’s legally required
  • When submitting your income tax return information to the CRA (i.e.: ​​T3, T4, or T5 slips)
  • When opening a bank account that earns interest for tax purposes (ie: RRSP)
  • When applying for government programs and benefits
  • When you’re asked to show a piece of identification
  • When you receive emails or text messages that ask for your SIN
  • When applying for jobs, post-secondary institutions, or credit cards
  • When completing banking transactions (i.e.: mortgage, line of credit, loans)
  • When renting a property or car

Can I use my SIN if I’m self-employed?

If you’re self-employed, in some cases, you can use your SIN instead of a business number, especially as a subcontractor or commission salesperson.

Read more on SIN and being self-employed.

How do I get my child’s SIN number?

Apply for a Social Insurance number when your child is born. It will come in handy sooner than you think. Get a jump on this so you’ll be ready when your child gets their first job. They do grow up so quickly.

Once your child turns 12 or older, they may apply for their own SIN.

At TurboTax, we take the security of your personal information seriously. We understand the importance of your SIN and what it can do. With that in mind, we’re happy to answer any questions you may have.

Know your taxes are done right, however you choose.

Filing on your own, with live help or handing off your taxes to an expert, with TurboTax you can be confident your taxes are done right.