How is the Iranian national ID check digit calculated?

Multiply the first nine digits by the weights 10,9,8,7,6,5,4,3,2, sum them, and take the remainder mod 11. If the remainder is below 2 the check digit equals it; otherwise the check digit is 11 minus the remainder.

How many digits is an Iranian national ID?

Ten digits. Because a leading zero is sometimes dropped on printed documents, this tool pads shorter input back to 10 digits before validating.

Why are repeated-digit codes rejected?

A code such as 0000000000 or 1111111111 can satisfy the arithmetic by coincidence but is never a genuine issued national ID, so the validator rejects all single-repeated-digit codes.

Does a valid checksum mean the person exists?

No. A valid checksum only confirms the code is internally consistent under the modulo-11 rule. It does not prove the person exists or that the ID is currently active.

Is my national ID sent anywhere?

No. The check runs entirely in your browser, so the code never leaves your device and nothing is logged or transmitted.

Iran National ID (Kod Melli) Validator

The Iranian national identity code (Kod Melli) is a 10-digit number issued to every Iranian citizen and used throughout banking KYC, HR onboarding and government services. The final digit is a modulo-11 check digit, so a single mistyped digit is detectable. This free validator runs the exact algorithm in your browser.

How it works

The official modulo-11 check-digit algorithm:

Take the first nine digits.
Multiply each by its weight: 10, 9, 8, 7, 6, 5, 4, 3, 2.
Sum the nine products.
Compute the remainder r = sum mod 11.
The expected check digit is r when r is less than 2, otherwise 11 - r.
The code is valid when the tenth digit equals that expected value.

A leading zero is sometimes lost when a code is stored as a number, so the tool pads shorter input to 10 digits. Codes made of one repeated digit are rejected even if the arithmetic passes.

Example

For 0084575948 the weighted sum is 212. 212 mod 11 = 3, so the expected check digit is 11 - 3 = 8. The tenth digit is 8, so the code is valid. Change any digit and the expected check digit no longer matches.

A valid checksum confirms the code is well-formed, not that the person exists. All processing stays on your device.