You can obtain a replacement Social Insurance Number (SIN) card through Service Canada, the federal agency that administers the program. To apply, visit the nearest Service Canada office in person with required identification documents—typically a valid government ID like a driver's license or passport, plus proof of citizenship or permanent residency. You'll need to complete an application form and provide documentation establishing your identity and status in Canada. Processing usually takes 2–4 weeks. Alternatively, some provinces allow online or mail-in applications; check your provincial Service Canada website for specific options in your area. If you've lost your card but still have your SIN number written down elsewhere, you don't urgently need a replacement card for most purposes—employers and financial institutions can verify your SIN directly. However, having the physical card is convenient for employment verification and other administrative tasks. There is no fee to replace a SIN card. If your card was stolen or you suspect fraud, report it to Service Canada immediately so they can flag your account for security purposes, though the SIN number itself cannot be changed.