The Kbis extract is the "identity card" of a French commercial company: it certifies its registration in the trade and companies register (RCS) and summarises its legal particulars. It is asked of any new supplier, subcontractor, business tenant or trade-credit customer. It is also one of the easiest documents to forge: a PDF, a layout everyone knows, and a reading that is often quick. The good news: everything it contains can be checked in public registers, for free.
A Kbis states the company name, legal form, share capital, registered office address, identification number (SIREN) and registering court ("RCS" followed by a city), APE activity code, registration date, duration, activity, the identity and date of birth of its directors, and any ongoing insolvency proceedings (safeguard, receivership, liquidation). It is issued by the clerk of the commercial court, online through Infogreffe, and dated the day it is issued: it is a snapshot, hence the custom of demanding one less than three months old.
Two frequent confusions. The "extrait K" is the equivalent for a sole trader. And a micro-entrepreneur, a craftsperson or a liberal professional has no Kbis: they prove their existence with a SIRENE status notice (INSEE) or an extract from the National Business Register (INPI). A "Kbis" presented by a micro-entrepreneur is, by itself, a warning sign.
This is the check that matters, and it is free. The official Annuaire des entreprises aggregates data from INSEE, INPI and the court clerks: administrative status (active or ceased), registered office, directors, establishments, creation date. Infogreffe shows the RCS record and issues the official extract; the BODACC publishes legal notices — registration, amendments, insolvency proceedings, deregistration.
Go through the Kbis line by line and compare: same SIREN, same name, same legal form, same office, same directors, same registration date, same court. A director missing from the register, a different address, a company "active" on paper but struck off or in liquidation in the register: each of these gaps means refusal until explained. A very recent amendment may not be published yet — then ask for the court's filing receipt, not for another Kbis.
Before you even open the register, the file can give itself away:
A genuine Kbis proves that a company exists. It does not prove that the person sending it represents that company. Impersonation of real companies, dormant companies bought as a front, and short-lived companies created for a few months of fraud all come with a perfectly valid Kbis.
So also check that your contact is among the directors — or holds a mandate —, that their e-mail domain is the company's, and that the company is neither struck off nor in insolvency proceedings. A registration a few months old, a token share capital and a large first order together justify additional guarantees.
A Kbis never comes alone. The bank-detail document must be in the exact company name; the invoice must carry a SIRET whose first nine digits are the Kbis SIREN and an intra-EU VAT number consistent with it (FR, a two-digit key, then the SIREN); for subcontracting, the URSSAF compliance certificate completes the statutory due-diligence file. Any inconsistency between these documents weighs more than the quality of each taken alone.
TrustyFile runs these cross-checks on the PDFs you upload: SIREN, SIRET and VAT check digits, the company's existence in the INSEE register, and traces of editing in the file. Comparing with the register itself remains a step nothing replaces.
Free SIRET checker: validates the 14-digit French establishment number with the Luhn formula, including the special rule for La Poste establishments. Runs locally.
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Free SIREN checker: validates the 9-digit French company number with the Luhn formula and derives the intra-EU VAT number it implies. Runs in your browser, nothing is sent.
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Free French VAT number checker: validates the two-digit key against the SIREN it precedes and the SIREN's own Luhn digit. Runs in your browser; use VIES for registration.
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