Canada SIN validator
How the SIN format works
- Format
- 9 digits
- Example
- 046454286
Things to watch for
- SIN is 9 digits and Luhn-valid — the same checksum used by many card numbers
- Format + checksum only — does not confirm the SIN is actually issued or belongs to a real person
- SINs starting with 9 are issued to temporary residents and are not permanent
^[0-9]{9}$A Social Insurance Number (SIN) is the 9-digit number Canada uses to track who’s eligible to work and who can access government programs and benefits. It’s usually written in three groups of three — like 046 454 286 — and employers, benefits administrators, and tax software all expect it in that shape. Because a SIN is entered by hand into so many forms, a single mistyped or transposed digit is one of the most common reasons a submission bounces back or a form flags an error — and that’s exactly the kind of mistake a checksum catches before it causes a problem.
How this validator works
Beyond confirming the number is 9 digits, this tool runs the Luhn checksum against the final digit — the same check-digit algorithm used by many card numbers — entirely in your browser. If the digits don’t add up the way the algorithm expects, the SIN as typed can’t be a validly constructed one, which usually means a digit was mistyped, swapped, or dropped somewhere in the sequence. Nothing about the number is looked up against any registry; the check is pure arithmetic on the digits you entered.
What a pass doesn’t tell you
A pass here means the number is correctly formatted and internally consistent — nothing more. It does not confirm the SIN was actually issued, that it’s currently active, or that it belongs to the person who gave it to you; only Service Canada or the person’s own records can establish that. Because a SIN is sensitive personal information, treat it carefully regardless of what this tool reports: don’t paste it into untrusted forms, don’t share it over unencrypted channels, and don’t store it longer than necessary.
Scope: this page checks SIN format and Luhn checksum only — a client-side sanity check for catching typos, not an identity or eligibility lookup. Use it to verify a SIN was entered correctly; use Service Canada for anything involving the person behind the number.
Content last reviewed 2026-07-09.
SIN FAQ
What does the first digit of a SIN mean?
It indicates the province, territory, or registrant type where the SIN was first issued — for example, SINs beginning with 9 go to temporary residents, such as work-permit or study-permit holders, and are not permanent numbers.
Does a valid SIN mean it belongs to a real person?
No. This check only confirms the number is 9 digits and passes the Luhn checksum used to generate real SINs — it does not look anything up. A checksum-valid number may never have been issued to anyone, so a pass is not proof of identity.
Is my SIN sent anywhere when I use this tool?
No. The check runs entirely in your browser using JavaScript — your SIN is never transmitted to a server, logged, or stored anywhere. Given how sensitive this number is, that matters more than it does for most forms.