Peru RUC validator
How the RUC format works
- Format
- 11 digits: 2-digit taxpayer type prefix + 8-digit body + 1 check digit
- Example
- 10123456781
Things to watch for
- The first 2 digits indicate the taxpayer type — 10 for natural persons and 20 for companies are the most common prefixes
- Format + weighted mod-11 check digit only — a pass doesn't confirm the RUC is currently active or registered with SUNAT
- A RUC issued to a natural person can identify a specific individual — this check runs entirely in your browser, so nothing you type is stored or transmitted
^(10|15|16|17|20)[0-9]{9}$The RUC (Registro Único de Contribuyentes) is the 11-digit taxpayer number Peru’s tax authority, SUNAT, assigns to individuals and companies — for example 10123456781. It’s required for issuing invoices, filing taxes, and most formal business activity in Peru, and its structure is built to be checked mathematically before it’s ever looked up in a registry.
The first 2 digits are a taxpayer-type prefix: 10 marks a natural person and 20 marks a company, with 15, 16, and 17 covering less common categories. The next 8 digits are the taxpayer’s body number, and the final digit is a check digit generated by weighting the first 10 digits and reducing the result modulo 11. Because that last digit is derived from the rest rather than freely chosen, a single mistyped digit in a RUC almost always fails the calculation instead of silently pointing to a different, equally valid taxpayer.
How this validator works
This tool checks that the input is 11 digits starting with a valid taxpayer-type prefix (10, 15, 16, 17, or 20), then runs the real weighted mod-11 formula SUNAT uses to generate a RUC’s check digit, entirely in your browser. Nothing is sent to a server, and there’s no signup.
What a pass doesn’t tell you
A pass confirms the number is a mathematically valid RUC — not that the taxpayer is currently active, in good standing, or registered for a particular tax regime with SUNAT. Only SUNAT’s own records can confirm current status.
Scope: this page and tool cover RUC format and checksum validation only — not SUNAT registration status.
Content last reviewed 2026-07-23.
RUC FAQ
What do the first two digits of a RUC mean?
They identify the taxpayer type. 10 is the prefix for natural persons (individuals), and 20 is the prefix for companies — the two most common cases. SUNAT also uses 15, 16, and 17 for a handful of less common taxpayer categories.
Is a RUC the same as a DNI?
No. A DNI is Peru's national identity number, while a RUC is an 11-digit taxpayer number SUNAT issues for tax purposes. They're managed by different agencies for different purposes, even though most individuals with a RUC also hold a DNI.
Does a valid checksum mean the RUC is active with SUNAT?
No. This tool only confirms the 11 digits pass the weighted mod-11 calculation SUNAT uses to generate a valid RUC — it doesn't confirm the taxpayer is currently registered or in good standing.