How is a SNILS checksum calculated?

Multiply each of the first 9 digits by a descending weight from 9 down to 1 and sum the products. If the sum is below 100 the checksum equals the sum; if it equals 100 or 101 the checksum is 00; if it exceeds 101 take the sum modulo 101, and if that result is 100 or 101 the checksum is 00.

How is a SNILS formatted?

A SNILS is 11 digits, usually written as XXX-XXX-XXX YY — three groups of three digits, then the two-digit check number. This tool accepts it with or without the dashes and space.

Does the checksum check the digits for being all equal?

The standard algorithm only validates numbers whose 9-digit body is greater than 001-001-998. Smaller numbers (including all-zero or repeated-digit test values) are outside the checksum's defined range, so this tool flags very low numbers as out of range.

Does a valid SNILS mean the person is insured?

No. A valid checksum confirms the number is internally well-formed. It does not confirm the SNILS is issued to a real, insured person. Use official Pension Fund / Gosuslugi services for that.

Is my SNILS sent anywhere?

No. The whole calculation runs locally in your browser. The number never leaves your device.

Russia SNILS Validator

A СНИЛС (SNILS) is the 11-digit individual personal account number on a Russian pension insurance certificate, issued by the Pension Fund. It is used in HR onboarding and Gosuslugi identity verification, and it carries a two-digit checksum so transcription errors can be caught instantly. This validator runs the official checksum in your browser.

How it works

The last two digits are a check number computed from the first 9 digits:

Strip non-digits. The number must be 11 digits, written as XXX-XXX-XXX YY.
Multiply the 9 body digits by descending weights 9, 8, 7, 6, 5, 4, 3, 2, 1 and sum the products.
Reduce the weighted sum:
- if sum < 100, the checksum is sum;
- if sum == 100 or sum == 101, the checksum is 00;
- if sum > 101, take sum mod 101, and if that is 100 or 101, the checksum is 00.
The SNILS is valid when the computed two-digit checksum equals the actual last two digits.

The checksum is only defined for 9-digit bodies greater than 001-001-998, so smaller numbers are reported as out of range.

Example

For body 112-233-445 the weighted sum is 1×9 + 1×8 + 2×7 + 2×6 + 3×5 + 3×4 + 4×3 + 4×2 + 5×1 = 95. Since 95 < 100, the expected check number is 95. A SNILS 112-233-445 95 therefore passes.

Notes

A valid checksum confirms the number is consistent, not that it is issued to a real insured person — use official Pension Fund / Gosuslugi services for that. Everything runs locally, so your SNILS never leaves your device.