🇨🇱 CHILE · TAX ID
RUT validator (free) — Chile
The RUT (Rol Único Tributario) is Chile's tax identifier issued by SII for both individuals and companies. The check digit can be 0-9 or the letter K (for value 10). This tool validates format and Mod-11 check digit client-side.
Validates locally — your data never leaves your browser. No tracking on input. Format and check-digit validation only.
Validates locally — your data never leaves your browser. No tracking on input.
How RUT validation works
A RUT has 7-8 base digits plus a single check digit. The canonical format is XX.XXX.XXX-X, where the last character can be 0-9 or K. The check digit is computed via a Mod-11 algorithm with weights cycling [2, 3, 4, 5, 6, 7] applied from right to left.
Take the body digits, reverse them, multiply each by the next weight in the cycle, sum the products, compute (11 − sum mod 11). If the result is 11 the check digit is 0; if 10 the check digit is K; otherwise the result itself.
This tool strips dots and hyphens so 12.345.678-5 and 123456785 both validate. It does not verify whether the RUT is registered with SII — that requires an SII service query.
Frequently asked questions
Why can the check digit be the letter K?
When the Mod-11 calculation yields 10, a single digit cannot represent it, so Chile uses the letter K. About 1 in 11 valid RUTs end in K.
Do individuals and companies use the same RUT format?
Yes. Chile uses the same RUT format for individuals and companies. Companies typically have higher numeric ranges (above 50 million) but the algorithm and structure are identical.
Does this validator confirm the RUT is registered with SII?
No. It validates format and check digit only. Confirming an active RUT requires a query to SII's online registry, which is not exposed as a public API.
Can I validate RUT via API?
Yes. Normadata's Verify API validates Chilean RUT alongside Argentine CUIT, Peruvian RUC and 17 other tax IDs with a single JSON call.
More resources
Want RUT validation in your app?
The Normadata Verify API validates Chilean RUT alongside 17 other Latin American tax IDs with a single JSON call.
See the Verify API→