Brazilian driving licence (CNH) validator

Check the structure and check digits of a Brazilian CNH national registration number using compared public conventions, without an official lookup.

Check a CNH number

The number is processed only in your browser. This tool does not send it, save it, or include it in links.

CNH national registration number

Use all 11 national registration digits, including leading zeroes. Dots, hyphens and plain whitespace are ignored. Do not use the mirror number, RENACH form number or security code.

Share only the tool link. The entered number is never included.

Result

Waiting for a number

Type or paste a registration number to check its structure and digits.

This check uses a community convention. Matching digits do not prove issuance, authenticity, ownership, validity or permission to drive.

Authenticate through the official Senatran service

Frequently asked questions

Which CNH number should I enter?

Enter the 11-digit national registration number. It differs from the mirror number, RENACH form number and security code. Keep leading zeroes.

Do matching digits prove authenticity?

No. A number can have matching digits without an issued licence. Use the official Senatran service for authentication.

Does this query Senatran?

No. All calculations run in your browser without querying official records. The number is not saved or included in shared links.

Does the result confirm validity or permission to drive?

No. This tool does not check expiry, licence categories, points, suspension, ownership or driving entitlement.

Why are some results inconclusive?

We compared public open-source implementations. They agree on most of the calculation but differ on three remainder pairs. For those cases, we assert neither a match nor a mismatch. We did not find a complete public official specification to confirm these exceptions.

About the CNH validator

The CNH validator helps detect typing errors in an 11-digit Brazilian driving licence national registration number. It checks structure and digit consistency against a compared community convention. It is not a Detran or Senatran service and does not authenticate documents.

How to check a CNH number

Enter the national registration number, read the result and guidance, then copy the entered digits if needed. Use the official service to confirm authenticity. Inconclusive results indicate disagreement between public references.