What is a Social Insurance Number?

Your social insurance number (SIN) is a unique 9-digit number that lets you work in Canada and access government programs and benefits (like the Canada Pension Plan, Employment Insurance program, or Canada Student Loans). Your SIN is formatted in groups of three digits (such as 234-567-890) and can be found on:

  • Your confirmation of SIN letter or valid SIN card issued by Service Canada
  • The first page of your previous year’s Canadian tax return or
  • Your notice of assessment or reassessment from the Canada Revenue Agency (CRA) or Revenu Québec

Remember, to successfully file your taxes, you’ll need to enter your SIN on your tax return – it is your main identifier with the CRA (and Revenu Québec, if applicable).

Your spouse only requires a SIN number if you are:

  • Preparing a coupled return
  • Splitting pension income with your spouse
  • Living in Québec and your spouse is a resident

If you are using our Do-it-yourself tax software and any of these situations apply to you, please contact one of our retail locations near you. Even if your spouse doesn't have a SIN number, our Tax Experts will be happy to help you with your return!

If you are using our Upload from Home service and any of these situations apply to you, send your Tax Expert a message from your Messages tab to let them know.