How is the Uruguayan RUT check digit calculated?

The DGI multiplies the first 11 digits by the weights 4,3,2,9,8,7,6,5,4,3,2, sums the products, and takes the remainder modulo 11. The 12th check digit is 11 minus that remainder, where a result of 11 becomes 0. A remainder that would produce 10 marks an invalid number.

What do the first two digits mean?

The first two digits encode the taxpayer type, for example companies and other legal entities. The authoritative validity test is the modulo-11 check digit; the prefix is shown for reference.

Does a valid RUT mean the taxpayer is registered?

No. A valid result confirms the RUT passes the DGI check-digit rule and is internally consistent. It does not confirm the taxpayer is registered or active. Confirm status on the official DGI portal before issuing electronic invoices.

Why does my RUT fail?

Most failures are a mistyped or transposed digit. Because the check digit depends on all 11 preceding digits, a single wrong digit breaks the test. The tool shows the expected check digit so you can locate the error.

Is my RUT sent anywhere?

No. The weighting and modulo-11 maths run entirely in your browser. Nothing is uploaded, which makes it safe to validate supplier and customer lists.

Uruguay RUT Validator

The RUT (Registro Único Tributario) is Uruguay’s 12-digit tax identifier issued by the DGI (Dirección General Impositiva). It carries a single modulo-11 check digit in the final position, calculated from the preceding 11 digits. This free validator runs the DGI algorithm and shows the full calculation.

How it works

The DGI uses a weighted modulo-11 scheme:

Take the first 11 digits and multiply them, left to right, by the weights 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2.
Sum the products.
Compute sum mod 11 to get a remainder.
The check digit is 11 - remainder. If that gives 11, the check digit is 0. A remainder that would yield 10 marks an invalid, never-issued number.

The 12th digit must equal that computed check digit for the RUT to be valid. The tool prints the weighted sum, the remainder, and the expected digit so the result is fully transparent.

Example and notes

Enter a 12-digit RUT and the tool weights the first 11 digits, sums them, takes mod 11, and compares the derived check digit to the entered 12th digit. Change any digit and the check digit will usually shift, revealing the error.

A valid result confirms the RUT is internally consistent under the DGI rule — it does not confirm the taxpayer is registered or active. For e-CFE (electronic invoice) compliance, confirm taxpayer status on the official DGI portal. All processing is local; your RUT never leaves your device.