Canadian · Validation
Canadian SIN validator.
Validate a Social Insurance Number against the Luhn check digit. Everything runs in your browser: no SIN ever leaves your device.
Inputs
Result
Enter a SIN and press Validate.
How SIN validation works
A SIN is a nine-digit identifier issued by Service Canada. Validity is checked with the Luhn algorithm: the same checksum used for credit cards. Doubling every second digit from the right, summing the parts, and checking that the total is divisible by 10 confirms the SIN is mathematically well-formed.
First-digit meaning
- 1–7: regular SIN (citizens, permanent residents).
- 9: temporary SIN (work or study permit holders); expires with the underlying permit.
- 0 and 8: not currently issued.
TNAADO Inc. · Toronto
What the check digit can and cannot tell you
A Social Insurance Number is nine digits carrying a Luhn check digit, so a mistyped number usually fails arithmetic before it reaches a person. The first digit indicates the region of registration, and a leading 9 marks a SIN issued to a temporary resident, which carries an expiry date tied to the holder’s immigration document. The check here runs entirely in your browser: nothing typed into this page is transmitted anywhere.
The mistake people make. Reading a passing checksum as a valid, active SIN. Luhn only proves the digits are internally consistent. It says nothing about whether the number was ever issued, to whom, or whether it is still valid, and only Service Canada can confirm that. Employers must see the card or a Service Canada confirmation, and a 9-series SIN has to be re-checked against its expiry date each time.
Privacy
This tool runs entirely in your browser. Nothing you type is transmitted, stored, or logged. Use it freely on shared devices.