What is the difference between SIREN and SIRET?

SIREN is a nine-digit number identifying the legal entity — the company itself. SIRET is fourteen digits: the SIREN plus a five-digit establishment code identifying one physical site. A company has exactly one SIREN and as many SIRETs as it has establishments. Getting this wrong is the single most common error in French company data: counting SIRETs counts locations, not businesses.

The French activity classification, aligned to the European NACE system. Every establishment carries one, which makes sector filtering reliable and — because NAF maps to NACE — comparable with company registers across the rest of Europe. It is the field that turns a national register into something you can query alongside German, Polish or Czech data.

Is French company data free and open?

Yes. The Sirene register is published as open data covering every registered business and establishment in France, updated continuously. Individual entrepreneurs may exercise an opt-out that restricts publication of their details, which is why a small share of records are less complete — that is the register working as designed, not missing data.

How do you filter French companies by région or département?

Carefully, because location lives on the establishment rather than the company. Filtering on an area returns every company with any establishment there, including national groups headquartered elsewhere. If you want companies actually based in a département, filter to establishments in that area and then keep only those flagged as the siège. Skipping that second step is what makes regional company counts from Sirene come out wrong.

Home › Guides › France company data

France company data: SIREN, SIRET, and the mistake almost everyone makes

Q: What is a siège social?

The registered head office of a French company — the establishment flagged as the seat of the legal entity. Every other establishment is a branch or secondary site. The distinction matters for any geographic analysis, because a company headquartered in Paris may have establishments in twenty départements, and a naive location filter will return it for all twenty.

France publishes one of the best open company registers in Europe — every registered business and every physical establishment, updated continuously, free to use. It also has a structure that quietly breaks naive queries. This guide covers what SIREN and SIRET actually mean, why location lives on the establishment and not the company, and how to build a regional filter that returns the companies you meant.

SIREN and SIRET: entity versus site

	SIREN	SIRET
Length	9 digits	14 digits (SIREN + 5)
Identifies	The legal entity	One physical establishment
How many per company	Exactly one	One per site
Use it to	Count and join companies	Map footprint and locations

This is the first thing to get right, because everything downstream depends on it. A retailer with 300 branches has one SIREN and 300 SIRETs. Count SIRETs and you have counted shops; count SIREN and you have counted businesses. Both are legitimate numbers — they are answers to different questions, and reporting one while meaning the other is the most common error in French market sizing.

The siège trap: why your département filter is wrong

Here is the structural quirk that catches people out, and it is worth spelling out because it is not obvious from the data model.

Address data in Sirene sits on the establishment. So when you filter by a département, you are asking "which establishments are here" — and the answer includes every branch of every national group headquartered in Paris or Lyon. Your list of "companies in the Nord" fills up with the local depots of businesses that are not from the Nord at all.

The fix is two-step:

Filter establishments to the geographic area you want.
Keep only those flagged as the siège — the registered head office of the entity.

Do only step one and you get footprint. Do both and you get companies actually based there. Which you want depends on the question — a logistics supplier probably wants footprint, a regional bank wants sièges — but you must choose deliberately, because the default behaviour silently gives you the first.

France SIREN / SIRET company data →

NAF codes: France in European terms

Every establishment carries a NAF activity code, and NAF is aligned to the European NACE classification. That alignment is more valuable than it sounds: it means a sector filter you build for France transfers directly to Czech, Polish, Slovak and Slovenian registers, and to the Nordic ones.

It is the same principle that makes CPV codes useful in EU procurement: a shared taxonomy turns a set of national datasets into one queryable European market. Build your sector logic on the code, not on the French-language activity label, and it will survive the border.

What a Sirene record gives you

Identity — SIREN, SIRET, legal name, trading name where declared, legal form.
Status — whether the entity and each establishment are active, and the creation date. Company age is a genuinely useful qualifier and it is free here.
Activity — NAF code at both entity and establishment level. These can differ, and the establishment code describes what happens at that site.
Location — full structured address per establishment, plus commune and département codes.
Size band — an employee-count bracket, where declared.

What it does not give you is contact detail: no email, no phone. Sirene is an identity and classification register. Treat it as the verified spine of a French dataset and enrich contact routes separately — via career sites, firmographic enrichment, or the company's own web presence.

The opt-out, and why some records are thinner

Individual entrepreneurs in France can exercise a publication opt-out that restricts how much of their record appears. This shows up in a fill-rate table as a block of sparse rows, and the instinct is to treat it as a data-quality defect.

It is not. It is the register honouring a legal right, and it is concentrated in sole-trader records rather than spread randomly. Reporting it as missing data misdescribes what happened — and, more practically, it tells you something useful about the row: a restricted record is very likely a one-person business.

A practical French pipeline

Define the geography question first — footprint or headquarters. Then build the filter to match, with the siège step if you meant headquarters.
Deduplicate to SIREN before counting anything, unless you are deliberately counting sites.
Filter on NAF codes, not activity text, so the logic ports to the rest of Europe.
Use creation date and active status as free qualifiers — company age and current trading status are two of the most predictive cheap fields in any register.
Enrich contact separately. Sirene will never give you an email; it was not built to.

Frequently asked questions

SIREN or SIRET?

SIREN is the company (9 digits), SIRET is one establishment (14). Count SIREN for businesses, SIRET for locations.

What is a siège social?

The registered head office establishment. Filtering to sièges is what turns a location query into a company query.

What are NAF codes?

France's activity classification, aligned to European NACE — so sector filters built on it work across EU registers.

Is Sirene free?

Yes, published as open data and updated continuously. Some sole-trader records are restricted by a legal opt-out.

Search French companies → See all 87 datasets