How to validate a CPF
- Paste the CPF with or without punctuation.
- Click Validate.
- Check that the check digits are correct and see the historical tax region when applicable.
Ontoom
CPF validator
Validate check digits and see the CPF tax region.
CPF
Important: Synthetic data for testing. Misuse is the user's responsibility.
Need a new number for a fixture? CPF generator.
What validation checks
Digit count, rejection of obvious sequences, and calculation of the two check digits (mod 11). No government registry lookup.
Validate vs generate
The validator checks a number you already have. The CPF generator creates a new synthetic number for tests. Different goals — use the right page for each task.
Frequently asked questions
- Does validating a CPF confirm the person exists?
- No. Validation here is mathematical only (check digits and format). Existence with the tax authority requires an authorized official lookup.
- Does it accept CPF with and without mask?
- Yes. You can paste 000.000.000-00 or just the 11 digits.
- Why is my CPF shown as invalid?
- Usually the check digits do not match, digits are missing, or the sequence is invalid (e.g. all identical).
- What is the tax region?
- A historical convention tied to the 9th base digit. Useful as a test reference; it does not prove the current real place of issue.
- Can I generate a valid CPF here?
- Yes. Use Ontoom’s CPF generator to create synthetic numbers and come back to the validator for manual entries.