Finance · free tool

SIRET and SIREN validator for French company identifiers

Validate the length, structure and Luhn key of French SIREN or SIRET numbers. Your data stays in your browser whenever the task can be processed locally.

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SIRET / SIREN Validator

SIREN ou SIRET

Accepts spaces, dots and hyphens. Local validation by length and Luhn key.

Result

Good to know

A SIREN or SIRET validator checks whether a French company identifier has the expected length and control key.

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Understand

Understand SIRET / SIREN Validator

What is SIRET / SIREN Validator?

A SIREN or SIRET validator checks whether a French company identifier has the expected length and control key.

Main use case: Validate SIREN or SIRET values before using them in forms, billing QA, CRM imports or test datasets.

Common use cases

Form validation: Check local format before submitting a company form.
CRM import: Detect malformed identifiers in exported lists.
Billing QA: Verify test values used in invoice scenarios.

How to use the tool

Paste a SIREN or SIRET.
Remove spaces or separators if needed.
Check length and Luhn feedback.
Use official sources when existence matters.

Best practices

Use realistic test values when validating forms, exports or API payloads.
Keep real customer, banking and production secrets out of public tools.
Check the output format before copying it into a production workflow.
Document whether a value is generated, validated, converted or only estimated.

Common mistakes

Confusing valid format with real-world validity: A generated or locally validated value can match a format without proving that it exists in an official system.
Using real production data: Public utilities are best for test data, demos, fixtures, QA and quick checks, not for confidential values.

Frequently asked questions

Does a valid SIRET prove a company exists?

No. Local validation checks structure, not official existence.

What is the Luhn key?

It is a checksum used to detect many typing mistakes in numeric identifiers.

Can I validate lists?

This tool is designed for quick checks; use batch scripts for large datasets.

Are my inputs sent to a server?

OnSubmit tools run in the browser whenever the task can be processed locally. Avoid pasting production secrets, real banking details or personal data into public tools.