Canadian · Validation

SIN validator: check a Canadian SIN number.

Type a 9-digit Social Insurance Number to check its format and Luhn check digit, and to see whether it is a temporary SIN. Everything runs in your browser: no SIN ever leaves your device.

Short answer: a valid SIN has 9 digits, starts with 1–7 (or 9 if temporary) and its Luhn checksum adds up to a multiple of 10. This check confirms format and checksum only, not that the number was issued to anyone.

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, summing the parts, and checking that the total is divisible by 10 confirms the SIN is mathematically well-formed. That is all this tool can say. It does not look the number up, so it cannot tell you whether the SIN was issued or whose it is. Facts below are as of October 2026.

How to tell if a SIN looks real

9 digits, no letters. Dashes or spaces are only formatting.
Passes the Luhn check (the table above shows the working for your digits).
First digit 1–7, or 9 for a temporary SIN. Per Service Canada, a SIN starting with 9 belongs to a temporary resident and expires with their immigration documents.
Not a placeholder. 000 000 000 technically passes the checksum, but repeated-digit patterns are not issued numbers.

A number can tick every box and still never have been issued. Treat this as a typo detector, not an identity check.

First digit and region (legacy, not reliable)

Older public documentation links the first digit to where a SIN was originally issued. Those regions no longer reliably describe the holder, because people move and numbering has changed, so never use this to infer where someone lives. Service Canada does not publish this table as a way to identify a person; it comes from secondary public documentation (Wikipedia: Social insurance number), checked October 2026.

First digit	Legacy regional meaning
1	Atlantic provinces
2–3	Quebec
4–5	Ontario
6	Prairies, Northwest Territories, Nunavut
7	Pacific region, Yukon
9	Temporary SIN (current, per Service Canada)
0, 8	Not used for ordinary issuance; flagged unrecognised by this tool

More SIN guides and tools

How to validate a SIN number: the Luhn check by hand, plus which typos it misses.
SIN number format: digits, grouping and the first digit.
Temporary SIN (9xx) checker: what a SIN starting with 9 means for expiry.
SIN number generator: Luhn-valid test numbers for developers.
SIN vs BN vs ITN, the employer SIN checklist and the SIN privacy guide.

Can you look up a SIN? No

There is no public SIN lookup and no legitimate site can give you the owner of a number. If you need to confirm your own SIN, use your SIN confirmation letter or contact Service Canada. Be cautious of anyone asking you for a SIN by text or email. Details: Service Canada, Social Insurance Number.

How to check a SIN, with examples

The Luhn check takes the nine digits, doubles every second digit starting from the second (digits 2, 4, 6 and 8 from the left), adds the digits of each doubled value, then adds everything. If the total ends in 0, the number passes.

Worked example: a number that passes

046 454 286 → digits 0, 4, 6, 4, 5, 4, 2, 8, 6. Doubling positions 2, 4, 6, 8 gives 8, 8, 8, 16 (16 counts as 1 + 6 = 7). Total: 0 + 8 + 6 + 8 + 5 + 8 + 2 + 7 + 6 = 50. Divisible by 10, so it passes the checksum. This is the widely used sample number for testing forms; it is not issued to anyone, and its first digit 0 is not an ordinary issued range.

Worked example: a number that fails

046 454 287 changes only the last digit. The total becomes 51, not divisible by 10, so it fails. That is why one mistyped digit is always caught.

The example numbers on this page are fixed test values, never randomly generated, so none can be a real person’s SIN. Press Try a test number above to load one.

Frequently asked questions

Is a SIN that passes this check a real SIN?

No. Passing means the nine digits are mathematically well-formed. Only Service Canada can confirm that a number was issued, and to whom. This tool never contacts any database.

How do I check whether a SIN number is valid?

Enter the nine digits above. The tool runs the Luhn check and reports Valid or Invalid, shows the step-by-step working, and reports the number type based on the first digit.

How can I tell if a SIN looks real?

A SIN has exactly 9 digits and passes the Luhn checksum. Its first digit is 1 to 7 for a permanent SIN or 9 for a temporary one. Patterns such as 000 000 000 or one repeated digit are placeholders, not issued numbers. Looking real is not the same as being issued.

Can you look up a SIN?

No. There is no public lookup. Service Canada does not let the public search for a SIN or the person it belongs to. An employer may ask to see your SIN document, and Service Canada can help you confirm or recover your own number. This tool only checks format and checksum.

How can I tell if a SIN is temporary?

Per Service Canada, a temporary resident's SIN starts with 9 and expires with their immigration documents. A permanent SIN does not expire. This tool flags any SIN starting with 9 as temporary.

What does the first digit of a SIN mean?

Historically the first digit was linked to the region where the SIN was issued, and 9 marks a temporary SIN. The regional meaning is legacy and not reliable today, so do not infer where someone lives from their SIN.

Why does my real SIN show as invalid?

Most often a mistyped digit; the Luhn check catches any single wrong digit and most swapped neighbours. Re-enter it carefully, and if it still fails, check the number against your SIN confirmation letter or card.

How does the SIN checksum (Luhn algorithm) work?

The ninth digit of a SIN is a check digit. To test a number, double every second digit (positions 2, 4, 6 and 8), add the digits of any result above 9, then add all nine values. If the total is a multiple of 10 the SIN passes. The same arithmetic catches any single mistyped digit and most swapped neighbours.

Which other numbers use the Luhn check?

Credit and debit card numbers and IMEI phone identifiers use the same Luhn calculation, as do several other national ID numbers. Each has its own length and rules, so a number that passes one check is not a valid number of another kind. The ID number validators directory lists the checkers for each type.

Is it safe to type a SIN here?

The check runs as JavaScript in your browser. The number is not sent, stored or logged. Still, only enter a SIN you are entitled to use, and never share a real one in a message or form you do not trust.

Sources: Service Canada, Social Insurance Number (temporary SINs, no public lookup); Luhn algorithm (ISO/IEC 7812-1); legacy first-digit table. Related: BN and GST/HST number validator, postal code validator.

Other ID number validators

Need to check a different kind of number? Every tool below tests format and, where one exists, the checksum, in your browser. Browse the full ID number validators directory.

Canada

United States

Latin America

United Kingdom and Europe

Asia-Pacific, Middle East and Africa

Bank, securities and company identifiers

Products, publishing and research identifiers

Vehicles, vessels, devices and travel documents

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.