How do I replace my lost or stolen SIN card?

To apply for a replacement Social Insurance Number (SIN) card, please see How do I apply for a SIN?

If you suspect that someone is using your Social Insurance Number (SIN), please see What should I do if I suspect someone is using my SIN?

What should I do if I don't remember my SIN? number

If you don't remember your SIN number, you can refer to your income tax return where your SIN number can be found.