Finance · company detailsValidate Russian details: INN, KPP, SNILS, OGRN

10 or 12 digits

A company has 10 digits, an individual or sole trader 12. The last digits are the checksum, the first four are the tax office code.

9 characters

The reason-for-registration code. It has no checksum but a strict format: inspectorate code, reason, serial number.

11 digits

The individual pension account number. The last two digits are the checksum, computed from the first nine.

13 / 15 digits

The primary state registration number: 13 digits for organisations, 15 for sole traders. It encodes the record kind, year and region.

mod 11

The last digit is derived from the others through a weighted sum. If it does not match, the number contains an error.

region · year

The leading digits of an INN or OGRN give the region and the tax office; an OGRN also carries the year. All offline.

It is the last digit of the number, computed from the rest through a weighted sum divided by eleven. A ten-digit company INN has one such digit, a twelve-digit personal one has two. If the calculated value does not match the number, there is a typo somewhere: digits swapped, a character lost, or the number simply made up. The check is instant and needs no database.

By length. An organisation's INN has ten digits, an individual's or a sole trader's has twelve. In both cases the first four digits are the code of the tax office that issued the number, and the first two of those are the region. Different lengths also mean different checksum formulas, so the tool first detects the type from the length and only then does the arithmetic.

From the first two digits: that is the region code in the tax classifier, while the first four identify the particular inspectorate. One catch matters here — tax codes are not the vehicle plate codes. For the tax service Crimea is 91, Sevastopol 92 and Baikonur 99, whereas plates use 82 for Crimea. This tool follows the tax reference; the other list would name the wrong region.

The first marks the kind of record: one and five mean a legal entity, three and four a sole trader. The next two digits are the year the record was made, two more are the region code, then comes the inspectorate code, the record's serial number and finally the check digit. The register has been kept since 2002, so the year is always in the twenty-first century: «92» there means a corrupted number, not 1992.

No, and that sets it apart from the other codes. Only the format can be verified: nine characters, of which four are the inspectorate code, two the reason for registration and three a serial number. Foreign organisations may have Latin letters in the reason characters. That is why the tool says «format is valid» for a KPP rather than «checksum is valid» — the latter would be a false promise.

Not with this tool, and we say so plainly. What is verified is the checksum and the format, that is, the absence of a typo. Whether the record exists in the state registers of companies, sole traders or the pension fund cannot be established this way: that requires the official databases, which means a request to a server. A number that passes here may belong to nobody — it is merely built by the rules.