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Pattern

Regex for French SIREN

9-digit SIREN — French company registration.

The French SIREN regex is ^\d{9}$ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

^\d{9}$
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What it matches

  • 732829320
  • 123456789

What it doesn't match

  • 12345678
  • 1234567890

Notes & gotchas

SIREN (Système d'Identification du Répertoire des Entreprises) is the 9-digit unique identifier for a French legal entity. Issued by INSEE. Same number appears in every SIRET for that company.

Code in your language

Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.

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Token-by-token breakdown

Every part of the pattern, left to right:

TokenMeaning
^start of string (or line in multiline mode)
\d{9}exactly 9 times: digit (0–9)
$end of string (or line in multiline mode)

About this pattern

European Union identifiers follow standards set by individual member states with EU-wide coordination (VAT VIES, IBAN/SEPA, etc.). The regex validates structure; for production use, validate via the appropriate registry.

Quick usage in different languages

This exact pattern — with the correct escaping and idioms for each language:

  • JavaScript: /^\d{9}$/.test(value)
  • Python: re.match(r"^\d{9}$", value)
  • Java: Pattern.compile("^\\d{9}$").matcher(value).matches()
  • C# / .NET: Regex.IsMatch(value, @"^\d{9}$")
  • Go: regexp.MustCompile(`^\d{9}$`).MatchString(value)
  • Ruby: /^\d{9}$/.match?(value)
  • PHP: preg_match('~^\d{9}$~', $value)

The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.

Common pitfalls

  • Anchored to the whole string. This pattern uses ^ and $, so it requires the entire input to match. To find it inside a longer text, drop the anchors and use the global (g) flag.
  • Escape it correctly per language. In Java and JavaScript strings each backslash must be doubled (\\d); in Python, Go, and C# use raw/verbatim strings so the backslashes survive.
  • Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the french siren against a source of truth (database, API, or checksum) where it matters.

Standards & sources

This pattern is based on the following authoritative specification(s) and issuing authorities. Formats can change — always confirm against the primary source.

Related patterns

More patterns in the Europe 🇪🇺 category:

See also

Browse all 300 patterns in the library, or open this regex in the interactive explainer to see a token-by-token breakdown, test against custom input, and generate code in seven languages.


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