CNH Validator (driver's licence number)

About this tool

The CNH número de registro is a single nationally-issued 11-digit number (9 base digits + 2 check digits). This tool applies the widely-used algorithm — a descending-weighted first check digit whose overflow feeds a correction factor into the ascending-weighted second — and rejects repeated sequences. Technical validation only.

How it works

1. Paste a CNH registration number (11 digits).
2. The validator applies the two check-digit algorithm and rejects repeated sequences.
3. Read the result locally in your browser — nothing is uploaded.

Example output

{
  "valid": true,
  "reason": "Valid CNH number.",
  "Number": "52798802310"
}

Frequently asked questions

Does a valid CNH number mean the licence exists?

No. This only checks the format and check digits — not whether a licence was issued to a driver.

Which CNH algorithm does it use?

The widely-used one: a descending-weighted first check digit whose overflow feeds a correction factor into the ascending-weighted second digit.

Does it run locally?

Yes — validation happens entirely in your browser; the number is never uploaded.

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