Russia INN validator
How the INN format works
- Format
- 10 digits (organisation) or 12 digits (individual or sole trader); the last 1 or 2 digits are weighted mod-11 check digits
- Example
- 7707083893
Things to watch for
- A 10-digit INN belongs to an organisation and has one check digit; a 12-digit INN belongs to a person (including sole traders) and has two
- The first 4 digits identify the tax office that issued the number — the first 2 are the region code
- Checksum only — a pass doesn't confirm the taxpayer is registered or that the INN belongs to a particular company
^([0-9]{10}|[0-9]{12})$An INN (ИНН, идентификационный номер налогоплательщика, taxpayer identification number) is the number Russia’s Federal Tax Service (ФНС) assigns to taxpayers. Organisations get a 10-digit INN. Individuals, including sole traders, get a 12-digit one. It’s the identifier Russian invoices, contracts and payment orders use to name each party.
What the digits encode
Every INN opens with a 4-digit code for the tax office that issued it. An organisation’s INN continues with a 5-digit record number and one check digit (4 + 5 + 1 = 10). A personal INN continues with a 6-digit record number and two check digits (4 + 6 + 2 = 12). The tool tells the two types apart by length.
How the check digits work
Each check digit is a weighted sum of the digits before it. The sum is taken mod 11 and then mod 10, so a remainder of 10 gives a check digit of 0.
- 10-digit INN: weights 2, 4, 10, 3, 5, 9, 4, 6, 8 on the first nine digits. For the example 7707083893, the weighted sum is 267 and the remainder is 3, which matches the final digit.
- 12-digit INN: the 11th digit comes from weights 7, 2, 4, 10, 3, 5, 9, 4, 6, 8 on the first ten digits. The 12th comes from weights 3, 7, 2, 4, 10, 3, 5, 9, 4, 6, 8 on the first eleven, including the 11th. Both must match.
What a pass doesn’t tell you
A pass confirms the digits are consistent. It doesn’t show that the taxpayer exists or is still registered, or that the number belongs to the company named on a document. A Russian legal entity also has a 13-digit OGRN from the state register, which has its own check digit.
Scope: Russian INN format and checksum validation only. It doesn’t cover taxpayer status or ownership.
Content last reviewed 2026-10-11.
INN FAQ
Do sole traders in Russia have a 10-digit INN?
No. A sole trader (индивидуальный предприниматель) is registered as an individual and uses their personal 12-digit INN, with two check digits. The 10-digit format is reserved for organisations, so a 10-digit number given for a sole trader is not that person's INN.
What is the KPP that often appears next to an INN?
The KPP (код причины постановки на учёт, registration reason code) is a separate 9-character code that Russian organisations quote alongside their INN, for example on invoices. It isn't part of the INN, it doesn't affect the INN's check digit, and this tool doesn't validate it.
Does a valid INN confirm who the taxpayer is?
No. A matching check digit only means the number is well-formed. It doesn't show that the INN is registered, active, or belongs to the company named on your invoice. Use the Federal Tax Service's own services to confirm a counterparty before relying on the number.