🇵🇾 PARAGUAY · TAX ID
RUC validator (free) — Paraguay
The RUC (Registro Único del Contribuyente) is Paraguay's tax identifier issued by the Subsecretaría de Estado de Tributación (SET). It uses a Mod-11 algorithm with ascending weights starting from 2. This tool validates format and 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 RUC (Paraguay) validation works
A Paraguayan RUC has a variable-length base (typically 3-8 digits) plus a single check digit, formatted as XXXXXX-X. Older RUCs were 4-5 digits; modern issuance uses 7-8 digits before the check digit.
The check digit is computed via Mod-11 with ascending weights starting from 2. Multiply each base digit (right to left) by 2, 3, 4, … sum the products, compute mod 11. If mod is 0 or 1, the check digit is 0; otherwise it is 11 − mod.
This tool strips dots and hyphens (so 80017726-3 and 800177263 both validate). It does not verify whether the RUC is active in SET's registry.
Frequently asked questions
Why is the RUC length variable?
SET issues RUCs sequentially as taxpayers register, so older numbers are short (4-5 digits) and newer ones are longer (7-8 digits). The algorithm handles any length by extending the weight sequence ascending from 2.
Do individuals and companies use the same format?
Yes. Paraguay uses the same RUC format for natural persons and legal entities. Individuals derive their RUC from their cédula plus the SET-calculated check digit.
Does this validator confirm the RUC is active with SET?
No. Format and check-digit validation only. Confirming an active RUC requires a query to SET's public service, which is not exposed as an open API.
Can I validate Paraguayan RUC via API?
Yes. Normadata's Verify API validates Paraguayan RUC alongside 17 other Latin American tax IDs with a single JSON call.
Want RUC validation in your app?
The Normadata Verify API validates Paraguayan RUC alongside 17 other Latin American tax IDs with a single JSON call.
See the Verify API→