RUT Validator (Chile)

How it is calculated

The tool removes dots and spaces and upper-cases the text. If there is a hyphen it splits the number there; otherwise the last character is taken as the check digit and everything before it as the body. The body must be digits only; the check digit must be 0-9 or K. Reading the body from right to left, each digit is multiplied by weights 2, 3, 4, 5, 6, 7, then 2 again, and the products are summed. DV = 11 − (sum mod 11), where 11 becomes 0 and 10 becomes K. If the computed digit equals the one typed, the RUT is valid. The tool also displays the RUT formatted with dots and a hyphen. It only checks the arithmetic of the Chilean RUT/RUN; it cannot tell whether that number was ever issued to a person or company.

Common mistakes

• Leaving out the hyphen and the check digit, for example typing 12345678: the tool then treats the 8 as the check digit and checks body 1234567, giving a computed digit 4 and invalid.
• Typing the check digit wrong, such as 12.345.678-9 instead of -5; the tool shows the correct digit it computed (5) so you can compare.
• Writing K as 10 or leaving it out. A check digit of K stands for a computed 10, and the lowercase k is accepted.
• Reading "valid" as proof that the person or company exists. Passing the check only means the digits are consistent, and a number like 0-0 also passes.
• Entering a foreign tax ID, passport or an old-format number with letters in the body; only digits are accepted before the check digit.