Peruvian RUC Validator

RUC: Peru's 11-digit taxpayer registry number

The RUC (Registro Único de Contribuyentes) is the 11-digit number that identifies every taxpayer in Peru — people and companies alike — administered by SUNAT. The first two digits announce the taxpayer type, and the last digit is a mod-11 check digit. This tool validates the prefix, length and checksum; 20100070970 is a sample company RUC.

For an individual, the RUC is usually their DNI (national ID) prefixed with 10 and given a check digit — so the RUC and DNI are tightly linked for natural persons.

The type prefix

• 10: persona natural (an individual, typically DNI-based).
• 15 / 17: persona natural no domiciliada (non-resident individual).
• 20: persona jurídica (a company/legal entity).
• Check digit: weights 5,4,3,2,7,6,5,4,3,2 over the first 10, then (11 − sum mod 11) mod 10.

Where it matters

• Invoicing: every Peruvian factura/boleta electrónica carries the issuer's and buyer's RUC.
• Tax filing: SUNAT keys all declarations and payments to the RUC.
• Business checks: the RUC reveals the entity type and tax status (active/suspended).
• Mock data / testing: validating prefix + checksum before a SUNAT lookup.

Common pitfalls

• Prefix must be valid: only 10, 15, 17, 20 are accepted types.
• Checksum ≠ active: a valid RUC can still be a suspended or de-registered taxpayer.
• Leading digits matter: store as an 11-character string, never an integer.
• RUC vs DNI: the 8-digit DNI is embedded in a 10-type RUC but isn't the same field.

FAQ

How is the RUC check digit computed? Weights 5,4,3,2,7,6,5,4,3,2 over the first ten digits, then (11 − sum mod 11) mod 10.

What does a 20 prefix mean? A persona jurídica — a registered company or legal entity.

Is an individual's RUC their DNI? Essentially yes — a 10 prefix plus the 8-digit DNI plus a check digit.