What is SIREN?
SIREN (Système d'Identification du Répertoire des Entreprises) is the 9-digit identifier assigned by INSEE (Institut national de la statistique et des études économiques) to every business registered in France. A SIREN identifies a legal entity as a whole — the company, association, or self-employed person — regardless of how many physical locations it operates.
Every French business has exactly one SIREN for its entire lifetime. It appears on official documents, contracts, invoices, and — under the September 2026 e-invoicing mandate — in the PPF's central directory that routes electronic invoices between businesses.
Structure
A SIREN is 9 numeric digits. The last digit is a check digit computed with the Luhn algorithm (modulo 10). Validators should always verify this check digit to catch typos.
Example: 732 829 320 (the historical SIREN for Danone).
SIREN vs. SIRET
The two are related but distinct:
A business can have multiple SIRETs (one for each physical establishment) but only one SIREN. The SIREN is effectively the "root" of the identifier hierarchy.
SIREN and the French VAT Number
France's VAT number is derived from the SIREN. The full format is:
FR + 2-digit key + 9-digit SIREN
The 2-digit key is computed from the SIREN itself using a modulo-97 algorithm. This means that if you know a valid SIREN, you can derive the VAT number deterministically — something ERP systems often do when onboarding French customers.
In EN 16931 terms:
FR + key + SIREN form.@schemeID="0002" (System Information Repertoire des Entreprises).SIREN in the French E-Invoicing Mandate
Under France's September 2026 e-invoicing reform, every French business must be registered in the PPF's central directory (annuaire) by its SIREN. When a sender needs to deliver an invoice, the directory maps the recipient's SIREN (or SIRET, if a specific establishment is targeted) to the PDP (Plateforme de Dématérialisation Partenaire) that the recipient uses.
In practice:
Peppol Usage
In Peppol, French participants are identified using ISO 6523 scheme 0002 (SIRENE) for SIREN, or scheme 0009 (SIRET-CODE) for SIRET. A Peppol participant ID for a French company using its SIREN looks like 0002:123456789.
Where SIREN Appears on an Invoice
On a Factur-X or UBL invoice issued by a French seller:
@schemeID="0002".FR + 2-digit key + SIREN.On the buyer side, BT-46 (Buyer identifier) and BT-47 (Buyer legal registration identifier) are the corresponding fields.
What ERP Developers Need to Know
1. Validate the check digit — A SIREN that fails the Luhn check should never reach the PDP. The tax administration rejects invoices with malformed SIRENs.
2. Derive the VAT number, don't store it separately — For French customers, the VAT number is a pure function of the SIREN. Storing both invites drift.
3. Handle the SIREN/SIRET hierarchy — Your data model should link establishments (SIRETs) to their parent legal entity (SIREN) and keep them in sync.
4. Query INSEE's public SIRENE API — For real-time validation and enrichment (company name, NAF code, address, status), INSEE publishes an open API. Check whether the SIREN is still active before issuing invoices.
5. Respect the PPF directory — From September 2026, the PPF directory is the authoritative source for routing. Cache it, refresh it regularly, and reconcile your customer master data against it.
Relation to Chorus Pro and Government Invoicing
For B2G invoicing, France's existing Chorus Pro platform already uses the SIRET (and by extension the SIREN) as the primary identifier for public-sector recipients. The PPF inherits this model and extends it to B2B. If you already integrate with Chorus Pro, your SIREN/SIRET handling will largely carry over.