The permanent nine-digit identifier assigned in France to each legal unit, from a company or sole trader to an association or public body. The National Institute of Statistics and Economic Studies records it in the Sirene register of businesses and their establishments. The digits do not describe the unit’s name, address, legal form, or activity.
The register has operated since 1973 under Articles R123-220 to R123-234 of the French Commercial Code. A filing on the single window for business formalities produces the number automatically, with no separate application. INSEE then issues a notice of listing. That notice is not a Kbis, the commercial-court extract for a business on the trade and companies register.
How the Digits Are Built
The first eight digits are handed out in sequence. The ninth is a check digit. INSEE tests it with the Luhn formula. From the right, the last digit stays as written and every second digit moving left is doubled. If a doubled value is 10 or more, add those two digits: 6 doubled is 12, and 1 + 2 = 3. The total must be a multiple of 10.
- No hidden code. The first eight digits do not encode region, size, legal form, or activity.
- Transcription check. If the Luhn total is not a multiple of 10, a digit was mistyped. A passing total is not proof that the unit exists.
- Not recycled. INSEE does not reissue the number after a natural person dies or ceases all activity, or after a legal entity is dissolved.
| Part | Digits | Role |
| Sequential stem | 8 | Positions 1 to 8. Assigned in order, with no meaning of their own. |
| Check digit | 1 | Position 9. Completes the Luhn check of the nine-digit number. |
| Establishment suffix | 5 | Not part of the company number. Appended to it so one site can be told from another, making 14 digits. |
A well-formed number can still be unused or closed. Existence and status come from the Sirene register, which INSEE publishes free of charge through the national business directory and the Sirene API.
One Legal Unit, Many Sites
Each site of that legal unit, such as the head office, a shop, or a warehouse, is identified by a 14-digit Système d’Identification du Répertoire des Établissements (SIRET). Those 14 digits are this company number plus a five-digit internal classification number. The first four of those five are an order number. The fifth checks the full 14-digit string with Luhn, separately from the check digit in position 9. The suffix does not encode the site’s activity or its address.
A legal unit keeps one company number and receives one 14-digit identifier per site. One head office and two shops mean one company number and three establishment identifiers. A change of address replaces the establishment identifier. The company number stays the same.
The register includes units in metropolitan France, Corsica included, and in Guadeloupe, Martinique, French Guiana, Réunion, Mayotte, Saint-Barthélemy, Saint-Martin, and Saint-Pierre-et-Miquelon. Foreign organizations with a representation or an activity in France are listed too. Public administrative bodies in New Caledonia, French Polynesia, and Wallis and Futuna are also covered.
Invoices and Tax Identifiers
French invoices show the company number for the legal unit and the 14-digit identifier for the site. The intra-EU Value-Added Tax (VAT) number used in France is FR, a two-digit key, and the same nine digits. The usual key is (12 + 3 × (the company number modulo 97)) modulo 97. The tax office issues that VAT number. A unit exempt from charging VAT can hold a company number and still have no active VAT number.
Since 1 September 2026, a domestic Business-to-Business (B2B) sale between VAT-liable businesses established in France must be sent as a structured Electronic Invoice (E-Invoice). The Direction Générale des Finances Publiques (DGFiP) requires the supplier’s company number and the customer’s company number on that invoice. The accepted forms are Universal Business Language (UBL), the UN/CEFACT Cross Industry Invoice (CII), and Factur-X, a Portable Document Format (PDF) with embedded structured data. A paper invoice, or an ordinary PDF sent by email, does not qualify. Delivery runs through an approved platform.
All in-scope businesses had to be able to receive these invoices from 1 September 2026. Large and mid-tier companies had to issue them from that date. Small enterprises and micro-enterprises, including freelance entrepreneurs, have until 1 September 2027 to issue them. Electronic reporting of transactions outside domestic business-to-business invoicing follows the same dates.
In the invoice data, ISO 6523 scheme 0002 labels this nine-digit number and scheme 0009 labels the 14-digit establishment identifier. When both appear, the first nine digits of the establishment identifier must match the company number. Approved platforms use the customer’s company number, or a chosen establishment identifier, to find where the invoice should go.
