Chile RUT / RUN validator
How the RUT / RUN format works
- Format
- 7-8 digits + 1 check character (0-9 or K)
- Example
- 760864285
Things to watch for
- Enter digits only (no dots or hyphen) — the check character is a weighted mod-11 digit, or K when the result is 10
- Checksum only — a valid RUT does not confirm the person or business is currently registered with the SII
- The same RUT format is used for both individuals (RUN) and businesses
^[0-9]{7,8}[0-9K]$RUT (Rol Único Tributario) and RUN (Rol Único Nacional) refer to the same underlying number in Chile — RUN is how the Civil Registry identifies you as a person, and RUT is how the Servicio de Impuestos Internos (SII), Chile’s tax authority, identifies you as a taxpayer or a registered business. In everyday use, most people just say “RUT” regardless of context. It’s conventionally written with dots grouping the digits and a hyphen before the final check character, for example 12.345.678-5, though this tool expects plain digits with no punctuation.
The number itself is 7 or 8 digits, and the final character is a check digit calculated by weighting each digit, summing the results, and reducing that sum modulo 11. Most of the time that produces a digit from 0-9, but when the calculation lands on 10, Chile’s convention is to write the letter K instead of a two-character result. Because the check character is derived rather than chosen, a single transposed digit almost always produces a mismatch — catching that before a form or contract gets rejected is the point of validating it.
How this validator works
This tool checks the digit count and recomputes the weighted mod-11 result against the final character (0-9 or K) entirely in your browser, with nothing sent to a server.
What a pass doesn’t tell you
A matching check character confirms the RUT/RUN is internally consistent — not that it’s currently registered with the SII or the Civil Registry, or that it belongs to the person or business you expect.
Scope: this page covers RUT/RUN format and check-digit validation only — not SII taxpayer registration status.
Content last reviewed 2026-07-22.
RUT / RUN FAQ
Is RUT the same as RUN?
They're the same number used for two purposes. RUN is how Chile's Civil Registry identifies a person, and RUT is how the tax authority identifies a taxpayer — an individual's RUT and RUN are identical, and the same numbering and check-digit system covers registered businesses too.
Why does a RUT sometimes end in the letter K?
The check character comes from a mod-11 calculation that normally yields a single digit 0-9. When the arithmetic result is 10, there's no single digit for it, so Chile's convention substitutes the letter K instead.
Do I need to type the dots and hyphen?
No — enter the digits (and K if that's the check character) with no dots or hyphen. The formatting on an ID card or invoice, like 12.345.678-5, is just for readability; the underlying value this tool checks has none.