You run a company in London, New York, Warsaw or Dubai, and next month three of your people start work on a French site, in a Paris office or at a client’s factory near Lyon. Your payroll provider tells you everything is in order because the team stays on home-country contracts and carries A1 certificates. Then a labour inspector walks onto the site and asks, in French, for the SIPSI declaration receipt, the name of your representative in France and the pay records translated into French. Within weeks, a fine of several thousand euros per worker lands on your desk, your French client receives a letter of its own, and URSSAF — the French body that collects social-security contributions (Unions de recouvrement des cotisations de sécurité sociale et d’allocations familiales) — opens a file asking why no French contributions were ever declared. This scenario plays out every week: sending staff to France is legally a posting of workers, known in French as détachement, and it triggers a full set of prior declarations, a local representative, French minimum pay and hours rules, and a strict proof system for social security. The good news is that each of these obligations can be fixed, even after an inspection has started, if you move fast and produce the right documents. This guide explains what a foreign company must file before day one, which French employment rules apply to posted staff, what a missing SIPSI declaration or a missing A1 really costs, and how to answer the inspector and URSSAF from abroad. Our companion hub for foreign founders setting up a French presence, covering bank account, Kbis extract, VAT and first hires, is Setting Up a Company in France as a Foreign Founder.
I. Your Employee Sent to France Is a Posted Worker: the SIPSI Declaration, the Local Representative and the Papers Inspectors Demand
French law starts from a simple principle: an employer based outside France may send employees to work temporarily on French soil only if a genuine employment contract ties the worker to that employer and the employment relationship continues throughout the posting. The statute states it plainly: “Un employeur établi hors de France peut détacher temporairement des salariés sur le territoire national, à condition qu’il existe un contrat de travail entre cet employeur et le salarié et que leur relation de travail subsiste pendant la période de détachement.” The same article lists the three classic patterns: work performed for the employer’s own account under its direction within a contract signed with a recipient established or operating in France, movement between establishments of the same company or group, and work performed for the employer’s own account with no French recipient at all. Agency work has its own parallel provision for temporary-work businesses in article L. 1262-2 of the Labour Code, and the whole posting title applies subject to international treaties and EU rules under article L. 1261-1. In practice, almost every cross-border assignment your company organises — installing equipment, auditing a subsidiary, staffing a French project for a client — falls inside this definition, including intra-group secondments that managers often wrongly treat as internal travel. Once the definition bites, two families of duties follow: administrative duties toward the French labour administration, and substantive French employment standards for the posted team.
A. How to File the Prior SIPSI Declaration and Appoint Your Representative in France
Before the first posted worker sets foot on the French site, the foreign employer must file a prior posting declaration through SIPSI, the online system for international service provision (Système d’information sur les prestations de services internationales) run by the Ministry of Labour, addressed to the inspection du travail — the labour inspectorate — of the place where the work starts. The governing text, article L. 1262-2-1 of the Labour Code, provides: “L’employeur qui détache un ou plusieurs salariés, dans les conditions prévues aux 1° et 2° de l’article L. 1262-1 et à l’article L. 1262-2, adresse une déclaration, préalablement au détachement, à l’inspection du travail du lieu où débute la prestation.” The declaration identifies your company, the French place of work, the posted workers, the dates and hours, the nature of the service and the applicable collective agreement, and it must be renewed or updated whenever the assignment changes. The administration’s guidance on this prior declaration is published on the Ministry of Labour’s SIPSI pages at travail-emploi.gouv.fr, which walk employers through the online filing. Filing late or not at all is the single most common finding on French construction sites, logistics platforms and IT projects staffed from abroad, and inspectors check it first because the SIPSI database tells them in seconds whether your posting exists.
The second prior duty is to appoint a representative of your company on French soil. The same article continues: “L’employeur mentionné au I du présent article désigne un représentant de l’entreprise sur le territoire national, chargé d’assurer la liaison avec les agents mentionnés à l’article L. 8271-1-2 pendant la durée de la prestation.” This représentant is not a figurehead: it is the person the inspector calls, visits and serves papers on, and who must be able to produce the file on demand throughout the assignment. Foreign groups typically appoint their French subsidiary’s manager, their French lawyer, or a specialised posting representative; what matters is a real person, reachable at a French address, holding a written appointment letter and a complete set of documents. The statute warns that ticking these boxes proves nothing by itself — “L’accomplissement des obligations mentionnées aux I et II du présent article ne présume pas du caractère régulier du détachement” — so a SIPSI receipt plus a representative never whitewashes a sham arrangement, but without them every inspection starts badly.
The third practical duty is to keep translated documents available where the work is performed. Article L. 1263-7 of the Labour Code requires: “L’employeur détachant temporairement des salariés sur le territoire national, ou son représentant mentionné au II de l’article L. 1262-2-1, présente sur le lieu de réalisation de la prestation à l’inspection du travail des documents traduits en langue française permettant de vérifier le respect des dispositions du présent titre.” Concretely, the inspector expects the SIPSI receipt, the A1 certificates, employment contracts, pay slips (bulletins de paie), time records, proof of working-time compliance and the appointment letter of the representative, all in French or with a French translation. Payslips in English only, time sheets kept on a server in Texas that nobody on site can open, or A1 forms “available on request from head office within two weeks” are treated as missing documents. Build one posting file per assignment — paper or immediately printable on site — before the team travels, and brief the site supervisor that the inspector may arrive unannounced and will ask for it first.
Foreign companies that send staff to a French client face one more trap: the client’s own duties. When a French customer — the donneur d’ordre (contracting party) or maître d’ouvrage (project owner) — hires a service provider that posts workers, it must check before the posting starts that the provider completed the SIPSI declaration and appointed a representative. Article L. 1262-4-1 of the Labour Code states: “Le donneur d’ordre ou le maître d’ouvrage qui contracte avec un prestataire de services qui détache des salariés, dans les conditions mentionnées aux articles L. 1262-1 et L. 1262-2, vérifie auprès de ce dernier, avant le début du détachement, qu’il s’est acquitté des obligations mentionnées aux I et II de l’article L. 1262-2-1.” If the provider never handed over a copy of the declaration, the client must itself file a declaration with the inspectorate within forty-eight hours of the posting’s start. This is why experienced French buyers now demand the SIPSI receipt and the representative’s details in the contract before your team boards the plane: your missing paperwork exposes them to a fine of their own, and they know it. Offer these documents spontaneously with your bid and you remove a frequent reason French prospects hesitate to sign with a foreign provider.
B. Which French Pay, Hours and Safety Rules Apply From Day One and What the A1 Certificate Proves
Posted workers remain employed by you, yet while they work in France they benefit from a protective core of French employment law, the so-called noyau dur. Article L. 1262-4 of the Labour Code guarantees the posted employee “l’égalité de traitement avec les salariés employés par les entreprises de la même branche d’activité établies sur le territoire national,” equal treatment with employees of same-sector companies established in France, across a closed list of subjects: individual and collective freedoms at work, discrimination and gender equality, maternity and parental leave, temporary-work safeguards, the right to strike, working time, compensatory rest, public holidays, paid annual leave and night work of young workers, holiday-fund membership, pay within the meaning of article L. 3221-3 including overtime uplifts, health and safety, minimum working age and youth employment, illegal-work prohibitions, and — for longer postings — further guarantees the article details. The decisive question for your budget is pay: every posted worker must receive at least the French statutory minimum wage, the SMIC (Salaire minimum interprofessionnel de croissance), plus the minimum rates of the French sector collective agreement (convention collective) covering the activity performed in France, including overtime uplifts, Sunday and night premiums, holiday pay accrual of ten percent for fixed-term style top-ups where applicable, and allowances the agreement treats as salary. A Polish, Romanian or American salary that is perfectly lawful at home becomes unlawful the day it falls below the French sector minimum for the same job, and the shortfall is recovered as back pay with interest.
Working time is the second shock for foreign employers. France caps the standard week at thirty-five hours, requires premium pay for overtime, limits daily and weekly hours, mandates daily and weekly rest, and restricts night work — and these caps apply to your posted team from the first day, whatever home-country contracts say. Keep French-style time records for every posted worker, make sure the site enforces rest breaks, and check the applicable convention collective for sector caps that can be stricter than the statute. Health and safety duties apply in full as well: risk assessment for the French site, safety instructions in a language the workers understand, protective equipment, accident reporting to the French system, and for construction and high-risk work the coordination and site-welfare rules your French client will impose. An accident involving a posted worker without French-compliant safety documentation turns a workers’-compensation file into a criminal-risk file, so treat safety paperwork as part of the posting file, not as an afterthought.
Social security is where the A1 certificate enters. Under the EU coordination rules — Regulation (EC) No 883/2004 on the coordination of social security systems — a worker genuinely posted to another Member State stays covered by the home state’s social-security scheme, and the home institution certifies this with the portable document A1 (formerly E101). The A1 is therefore the only paper that lets you answer URSSAF’s first question: why were no French contributions declared for people working on French soil? The Cour de cassation confirmed the mechanism in a published ruling of 16 October 2025, appeal No. 23-14.039, holding that where posted workers were never declared to the French institutions, “il appartient à l’employeur de prouver que la législation française n’est pas applicable à ces salariés en fournissant à l’organisme chargé du recouvrement des cotisations de sécurité sociale le formulaire A1, anciennement E101, prouvant leur assujettissement à la législation de leur pays d’origine,” and that failing that proof, the company faces reassessment for concealed work — full text on Légifrance (Cass. 2e civ., 16 Oct. 2025, No. 23-14.039, published in the Bulletin). Get A1 certificates issued by your home institution before departure, check every name, date and French place of work on each form, and carry them in the site file: an A1 applied for after the inspection starts is better than none, but an A1 already on site ends the argument immediately. URSSAF’s own pages for foreign employers on international mobility at urssaf.fr describe the same expectation from the collector’s side.
One warning closes this picture: a valid-looking A1 does not protect a sham. The criminal chamber of the Cour de cassation ruled on 2 March 2021, appeal No. 19-80.991, that concealed-work offences “peuvent être établis, nonobstant la production de certificats E101 ou A1, lorsque les obligations déclaratives qui ont été omises ne sont pas seulement celles afférentes aux organismes de protection sociale (article L. 8221-3, 2°, du code du travail) ou aux salaires ou aux cotisations sociales (article L. 8221-5, 3°, du code du travail),” giving as examples a missing registration with the trade-and-companies register (registre du commerce et des sociétés, the RCS — the French company register that issues the Kbis extract) for concealment by hidden activity, or missing pay slips for concealment of employees — see Légifrance (Cass. crim., 2 Mar. 2021, No. 19-80.991, published in the Bulletin). The ruling relays the Court of Justice of the European Union’s Bouygues judgment of 14 May 2020, case C-17/19, that posting certificates “s’imposent aux juridictions de l’Etat sur le territoire duquel les travailleurs exercent leurs activités uniquement en matière de sécurité sociale” — they bind the host state’s courts only for social-security purposes. In that case the managers were convicted of concealed work, unlawful lending of labour, forgery and misuse of corporate assets, with suspended prison terms, 45,000-euro fines, five-year professional bans and confiscations. The lesson for honest companies is symmetrical: genuine postings with real A1 certificates, real SIPSI filings and real French pay have nothing to fear, while letterbox arrangements with home-state activity limited to internal or administrative management fall under article L. 8221-3, 3° of the Labour Code, which expressly treats as concealed work “s’est prévalue des dispositions applicables au détachement de salariés lorsque l’employeur de ces derniers exerce dans l’Etat sur le territoire duquel il est établi des activités relevant uniquement de la gestion interne ou administrative, ou lorsque son activité est réalisée sur le territoire national de façon habituelle, stable et continue.” If your French operations are permanent and continuous, stop posting and hire or incorporate instead — our hub article above explains the subsidiary route.
II. Your Posting Is Challenged in France: the Labour Inspector’s Fine, the URSSAF Bill and How a Foreign Company Fights Back From Abroad
Most foreign employers discover French posting law through an inspection, not through a textbook. The visit usually starts quietly: an inspector (inspecteur du travail) arrives on site, notes the foreign number plates on the vans, interviews two or three workers, photographs the notice board and asks the site supervisor for the SIPSI receipt, the representative’s details and the French-translated file. If the answers are vague, the inspector returns with colleagues, extends the visit to pay and hours records, and sends a formal letter listing the breaches found. From that letter, three bills can follow in parallel: an administrative fine for the missing declaration, a separate fine for your French client, and a social-security reassessment for unpaid French contributions — each with its own procedure, deadline and judge. Understanding the three tracks is what lets you respond in the right order instead of answering everything with one confused letter.
A. How Much a Missing SIPSI or A1 Costs: 4,000 Euros Per Worker, Client Fines and the Contribution Reassessment
The employer’s fine is automatic in structure and painful in amount. Article L. 1264-1 of the Labour Code provides: “La méconnaissance par l’employeur qui détache un ou plusieurs salariés d’une des obligations mentionnées à l’article L. 1262-2-1, au troisième alinéa du II de l’article L. 1262-4, à l’article L. 1262-4-4 ou à l’article L. 1263-7 est passible d’une amende administrative, dans les conditions prévues à l’article L. 1264-3.” Every missing piece — no SIPSI declaration, no appointed representative, missing documents on site — is a separate breach, and the pricing is set by article L. 1264-3: “Le montant de l’amende est d’au plus 4 000 € par salarié détaché et d’au plus 8 000 € en cas de réitération dans un délai de deux ans à compter du jour de la notification de la première amende. Le montant total de l’amende ne peut être supérieur à 500 000 €.” Five posted workers with no declaration therefore expose you to up to 20,000 euros on a first finding, doubled on a repeat finding within two years, within an overall cap of half a million. The authority must weigh “les circonstances et la gravité du manquement, le comportement de son auteur, notamment sa bonne foi, ainsi que ses ressources et ses charges,” so a first-time omission by a company that regularises immediately pays far less than a repeat player that ignores the inspector — but the starting arithmetic concentrates minds. The administration has two full years from the breach to act — “Le délai de prescription de l’action de l’administration pour la sanction du manquement par une amende administrative est de deux années révolues à compter du jour où le manquement a été commis” — and the fine is collected like other State debts, with no suspensive effect for challenges to enforcement: “L’amende est recouvrée comme les créances de l’Etat étrangères à l’impôt et au domaine. L’opposition à l’exécution ou l’opposition aux poursuites n’a pas pour effet de suspendre l’action en recouvrement de la créance.” Paying late adds surcharges, so never treat the fine notice as a letter you can answer next quarter.
Your French client is fined on a parallel track, which is why it will pressure you the moment it is notified. Article L. 1264-2 of the Labour Code makes the project owner, contracting party or user company liable to the same administrative fine where its contractor missed the SIPSI duties and the client failed its verification duty, skipped its own 48-hour declaration, or breached related information duties. In practice the inspector notifies the client, the client invokes the warranty and indemnity clauses of your service contract, and you end up reimbursing the client’s fine on top of your own unless your contract caps that pass-through. Review your French service agreements now: add a clause in which you warrant that SIPSI filings and A1 certificates are in place before mobilisation, undertake to deliver copies on demand, and accept a defined indemnity — and mirror it with a clause requiring the client to forward any inspection letter to you within days, because its deadlines run even while the letter sits in its mailroom.
The third track is social security, and it is usually the most expensive. Where posted workers were never declared in France and no valid A1 proves home-state cover, URSSAF treats the French pay as a concealed payroll and reassesses contributions on the entire amount, using the general contribution base of article L. 242-1 of the Social Security Code, which subjects all sums paid in consideration or on the occasion of work to contributions. The sequence follows the standard collection ritual: control, letter of observations (lettre d’observations) inviting your comments, formal demand (mise en demeure), then an enforceable order (contrainte) served for collection. The 16 October 2025 ruling described above shows exactly how this ends when the employer cannot produce A1 forms: the reassessment stands, and the Cour de cassation quashed the appeal judgment that had cancelled the letter of observations and the demand — “CASSE ET ANNULE, en toutes ses dispositions, l’arrêt rendu le 9 février 2023” — sending the case back to the Metz appeal court and ordering the company to pay 3,000 euros under article 700 of the Code of Civil Procedure. Add back pay owed to underpaid workers, the client’s indemnity claim and your own legal costs, and a six-month posting of a five-person team can easily cost more than the margin on the French contract. That is the commercial reason to fix the file before URSSAF prices it for you.
B. How to Answer the Inspector and URSSAF Within the Deadline and Fix Your File Without Flying to Paris
When the inspector’s letter arrives, work in this order. First, diary every deadline the same day: the fine procedure gives you a short window to submit written observations before the authority fixes the amount, and the statute sends any challenge to the administrative court with no hierarchical appeal — “L’employeur, le maître d’ouvrage ou le donneur d’ordre peut contester la décision de l’administration devant le tribunal administratif, à l’exclusion de tout recours hiérarchique.” A lawyer in Paris or in the region of the site can file and plead for you; neither the observations nor the court appeal require your directors to travel. Second, appoint the French representative immediately if none exists, file or correct the SIPSI declarations for the ongoing posting, and assemble the translated site file described in part I — SIPSI receipts, A1 certificates, contracts, pay slips, time records and the appointment letter. Third, write to the inspector through counsel admitting nothing about intent, showing the fresh filings, documenting good faith — first posting, immediate correction, language difficulties now solved by a representative — and asking the authority to weigh those circumstances as article L. 1264-3 requires. Inspectors and fining authorities reduce penalties for companies that visibly come into compliance; they increase them for companies that argue the law does not apply to foreigners. If the site is in Paris or anywhere in Île-de-France, the file is handled by the Paris labour inspectorate and the DREETS Île-de-France (Direction régionale de l’économie, de l’emploi, du travail et des solidarités — the regional state service for labour matters), which process a high volume of posting files and expect a professionally presented response in French; an English-only reply from head office with no representative is the fastest route to the maximum.
Answer URSSAF on its own separate track, with the same discipline. Reply to the letter of observations within the stated deadline, worker by worker: produce each A1 with its issue date and coverage period, reconcile every payslip with the declared home-state base, and explain each gap — a worker who joined mid-project, a certificate renewed late, a name misspelt on the form — with dated proof. Challenge the mise en demeure and any contrainte before the correct judge within the deadline printed on each document, and never let an enforceable order become final through inattention while you negotiate informally with the controller. Where A1 certificates are missing, ask your home institution for them at once and, in parallel, prepare the fallback: voluntary disclosure of the French payroll with payment of the contributions reduces penalties and ends the concealed-work characterisation far more cheaply than a reassessment imposed after a fight. Keep the two disputes consistent — the story you tell the inspector and the story you tell URSSAF must match on dates, headcount, hours and pay, because both administrations read each other’s files.
Finally, close the file structurally so the next posting starts clean. Calendar the two-year repeat window from any first fine, because a second breach within two years doubles the per-worker ceiling to 8,000 euros. Renegotiate the French client’s contract with the warranty, document-delivery and letter-forwarding clauses described above. Decide honestly whether the activity is still temporary posting or has become permanent French operations: teams present “de façon habituelle, stable et continue,” in the words of article L. 8221-3, 3°, must move to French hiring or a French subsidiary rather than a new round of SIPSI filings. And keep one standing posting kit at head-office level — template SIPSI data, representative appointment letter, translation checklist, A1 request procedure, time-record model and the applicable convention collective minima — so each new assignment files before departure instead of after the inspector’s visit.
Conclusion
Sending your own people to work in France is not business travel: it is a posting that French law surrounds with prior declarations, a local representative, translated site documents, French minimum pay and hours, and A1-backed social-security proof. The SIPSI filing and the representative cost little and take days; the fine for skipping them runs to 4,000 euros per worker, your French client is fined alongside you, and URSSAF reassesses the whole payroll where no valid A1 justifies the absence of French contributions — with the Cour de cassation backing controllers who demand posting documents and quashing judgments that cancel their reassessments. The two 2025 and 2021 rulings discussed here draw a clear line: genuine postings, documented before departure and paid at French rates, survive inspections and court review, while sham arrangements fail even behind stacks of A1 forms. File early, pay French rates, keep the translated file on site, and answer every letter within its deadline through French counsel. Handled that way, a posting inspection becomes an administrative formality instead of the most expensive lesson of your French expansion.
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