International · Paraguay
Paraguay RUC validator.
Validar RUC: check the verification digit of a Paraguayan RUC such as 80028061-0, or find the digit for a RUC without it. It runs in your browser and does not query the tax authority.
How it works: multiply the digits of the RUC body from right to left by 2, 3, 4, 5, …, add the products, and take the remainder mod 11. If the remainder is greater than 1 the check digit is 11 minus the remainder; if it is 0 or 1 the check digit is 0.
Inputs
Result
Enter a number and press Check.
How the check works
| Part | What happens |
|---|---|
| 1 | Take the body digits (without the check digit) |
| 2 | Multiply from the right by 2, 3, 4, 5, … |
| 3 | Add and take the remainder mod 11 |
| 4 | Check = 11 − remainder if the remainder is above 1, otherwise 0 |
Worked example 44444401: right to left 1×2 + 0×3 + 4×4 + 4×5 + 4×6 + 4×7 + 4×8 + 4×9 = 158; 158 mod 11 = 4; 11 − 4 = 7. The RUC is 44444401-7.
What this does not tell you
We could not find this formula published by the tax authority (DNIT, formerly SET), so it comes from python-stdnum, which this tool is tested against. The 80 prefix on 8-digit bodies is only noted, not required. A matching digit does not show the RUC is registered.
Sources
python-stdnum, stdnum/py/ruc.py; DNIT Paraguay (tax authority). Retrieved 16 October 2026.
Official register: DNIT Paraguay. Open it in a new tab and enter the number there; this page never sends the number anywhere.
Frequently asked questions
Is my RUC my cedula number?
For an individual the RUC is generally the cedula number followed by a check digit, so you can test it here.
What if the remainder is 0 or 1?
The check digit is 0 in both cases.
Does a valid result show the RUC is active?
No. Confirm on the DNIT site.
Format and check digit only — not an official lookup
This tool works entirely in your browser. A passing result does not prove that a number was issued, is active, or belongs to anyone, and it is not verification by any government. Nothing you type is transmitted, stored or logged.