What is the difference between a 10 and 12 digit INN?

A 10-digit INN belongs to an organisation (legal entity) and has one check digit. A 12-digit INN belongs to an individual or sole trader and has two check digits.

Does a valid checksum mean the company really exists?

No. The check digit only proves the number is internally consistent. It does not confirm the entity is registered with the FNS.

Is my INN uploaded anywhere?

No. All validation happens locally in your browser and nothing is sent over the network.

Russia INN Validator

Check a Russian INN (10 or 12 digit) check digits — in your browser.

Russian INN validator

The INN (ИНН — taxpayer identification number) is 10 digits for an organisation and 12 digits for an individual or sole trader. The final digit (or final two digits) is a control digit computed with the federal tax service weighting formula.

Paste a number and this tool detects the type, shows the region code from the first two digits, and confirms whether the check digit(s) are valid — all in your browser, with nothing uploaded.