You run a company in London, New York, Dubai, Singapore or Tel Aviv. A French client signs, your French subsidiary needs hands on site, or a Paris construction project needs your crew for three months. You book flights, you send two trusted employees, and you assume their foreign employment contracts travel with them. In France, that assumption triggers one of the most inspected procedures in French labour law: the posting of workers, known as detachement. Before the first day on French soil, a prior declaration must be filed on SIPSI, the online portal for international service provision run by the Ministry of Labour, a contact person must be appointed in France, French minimum pay and working-time rules must apply, and a full file must wait on the work site for the labour inspector. Miss one step from abroad and the price rises fast: up to 4,000 euros per posted worker, joint payment of back wages with your French client, a full URSSAF reassessment, and in serious cases a criminal prosecution for concealed work. This guide explains, for a foreign owner who lives outside France, how to post staff lawfully, what papers the inspector will demand, and how to fix a failed posting before it becomes a court case.

I. How do you lawfully post staff to France from abroad: SIPSI declaration and papers on site?

A. Who must file the prior posting declaration on SIPSI and appoint a representative in France?

French law starts from a simple principle. The statute provides: “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.” That sentence comes from Article L1262-1 of the French Labour Code, and it carries three practical tests for a foreign founder. Your company must be genuinely established outside France, each posted worker must remain your employee under a real employment contract, and the assignment must be temporary. The same article lists the three accepted patterns: work performed for your company under your direction within a contract signed with a recipient established or operating in France, movement between establishments of the same company or between companies of the same group, and work performed for your own account without a contract with a recipient. If you send staff to your own French subsidiary, the second pattern covers you. If you send a team to a French client site, the first pattern covers you. If none of the three fits, you are not posting workers at all: you are hiring in France, and you need a French employment structure instead.

Once the pattern fits, two prior duties apply, and both sit with the foreign employer. The statute 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.” That is Article L1262-2-1 of the French Labour Code. In practice the declaration is not a letter to a local office. It is filed online on SIPSI, which stands for Systeme d’information sur les prestations de services internationales, the national online portal for posting declarations, at sipsi.travail.gouv.fr, and the official filing guide is published at service-public.fr declaration prealable de detachement with the Ministry of Labour doctrine at travail-emploi.gouv.fr SIPSI page. You file before the posting starts, for the place where the work begins, and you describe the company, the workers, the dates, the hours, the place of work, and the nature of the service. The portal issues a receipt. Your French client will ask for a copy on day one, because the client has its own verification duty, explained below. Keep the receipt with the travel file, the service contract, and the proof of filing date: inspectors check dates first, and a declaration filed after the start is treated as a missing declaration.

The same article imposes a second duty that foreign owners often discover too late: you must appoint a representative of the company on French territory, tasked with liaising with the inspection services during the assignment. A foreign phone number and an email address in another time zone do not satisfy this duty. The representative must be reachable in France, able to produce the documents listed below without delay, and able to answer the labour inspector, called the inspection du travail, the field service operating under the DREETS, the Regional Directorate for Economy, Employment, Labour and Solidarity, the regional authority that supervises labour inspection. Many groups appoint their French subsidiary manager, their French lawyer, or a dedicated posting correspondent with a written appointment letter, a French address, and a direct telephone line. State the representative clearly in the SIPSI declaration. If the inspector calls and nobody in France can produce the file, the file is treated as absent.

Two related duties complete the picture. The framework article Article L1261-1 of the French Labour Code recalls that posting rules apply subject to international treaties and European Union instruments, which matters for social security coordination and for the A1 certificate, the portable European document proving that a worker posted inside the European Union or European Economic Area remains affiliated to the home social-security scheme. And the client-side verification article Article L1262-4-1 of the French Labour Code requires the project owner or principal, called the maitre d’ouvrage or donneur d’ordre, who contracts with a service provider posting workers, to check before the posting starts that the provider has completed the SIPSI declaration and the representative appointment, and, failing receipt of a copy of the declaration, to file a substitute declaration with the labour inspectorate within forty-eight hours of the start of the posting. In plain terms: your French client is legally required to ask you for the SIPSI receipt before you start, and to report you to the inspectorate within two days if you cannot produce it. Send the receipt before the workers board the plane, not after the inspector arrives.

Special cases deserve a short warning. Postings through a foreign temporary-work agency follow a dedicated information chain under the same Article L1262-2-1 of the French Labour Code, with the user company informing the agency before the posting of the applicable pay rules. Long postings beyond twelve months, extendable to eighteen with a reasoned notification, shift toward full application of French labour law except for termination rules and supplementary pension schemes. Transport, construction, and public-procurement sites face sector checks, including the BTP card on building sites. Non-European employers must also prove lawful social-security coverage, either through a bilateral social-security agreement or through French affiliation, and must hold work authorisations for third-country nationals where required. None of these details replaces the two core steps: a timely SIPSI declaration and a real representative in France, both completed before day one.

B. Which pay, hours and documents must be ready for the labour inspector on the work site?

Posting is not a way to keep home pay on French soil. From day one, posted workers benefit from the hard core of French employment protections: the statutory or extended collectively-bargained minimum wage, overtime rates, maximum working time and rest periods, paid leave rules, health and safety duties, and equal-treatment guarantees. The applicable minimum is not your home salary converted into euros. It is the French SMIC, the national statutory minimum wage, or the higher minimum set by the extended branch collective agreement that covers the activity performed in France, for example the building, cleaning, hotel, road-transport or engineering agreements. The branch agreement is identified by its IDCC number and its geographic and professional scope. A foreign founder who posts engineers to Paris under the engineering agreement, or masons to Lyon under the building agreement, must pay at least the French conventional minimum for the right classification, add the overtime premiums for hours above thirty-five per week, grant the daily and weekly rest, and record every hour. The payslip must show it, and the inspector will compare the SIPSI hours, the time sheets, and the bank transfers.

Social security follows a parallel track that confuses many foreign owners. Inside the European Union, European Economic Area and Switzerland, a posted worker can remain under home social security for up to twenty-four months with an A1 certificate issued by the home institution under Regulation 883/2004, provided the worker was affiliated at home before the posting, the posting is temporary, and no worker is sent to replace another posted worker at the same post. The certificate must be requested before departure and carried or made available on site. For postings from outside that European coordination zone, coverage depends on bilateral social-security agreements signed by France, and where no agreement maintains home coverage, French affiliation and French contributions apply from the first day of work. URSSAF, the French agency that collects social-security contributions, checks this point systematically during site visits and during later desk audits. Keep the A1 certificates or the agreement-based proof next to the SIPSI receipts. A missing A1 does not automatically create a posting fine, but it moves the file toward a far heavier URSSAF reassessment for undeclared French wages.

The document list the inspector can demand is fixed by regulation, and it is long on purpose. Under Article R1263-1 of the French Labour Code, the employer established outside France keeps at the workplace of the posted worker, or where materially impossible at any other place accessible to its appointed representative, and produces without delay at the request of the labour inspectorate, the file proving the posting. The required items include the employment contract or equivalent document showing the place of recruitment, any work authorisation for third-country nationals, proof of an equivalent pre-employment medical examination where applicable, payslips or equivalent proof of pay with gross remuneration, pay period and hours distinguishing standard and premium hours, leave and public holidays with related pay elements, applicable branch agreement title where relevant, and affiliation to paid-leave and bad-weather funds where applicable, plus proof of actual payment of wages and a daily time record showing the start, end and duration of each worker’s working day. For postings of one month or more, individual payslips or equivalent documents are required. For shorter postings, any document proving compliance with the minimum pay suffices, but inspectors still expect bank proof. For companies established outside the European Union, the employer must also hold proof of lawful social-security status under an international agreement. Translate key documents into French or provide a certified summary: an inspector who cannot read the file treats it as unusable.

Inspection powers and information sharing have grown. Under Article L1263-1 of the French Labour Code, the control officers and the authorities coordinating their action may share all information and documents needed to enforce the posting title, including with officers holding equivalent powers in foreign states. In practice, the labour inspector, the URSSAF auditor, the tax auditor and the police unit against illegal work compare SIPSI data, DPAE hiring declarations, payslips, A1 certificates and client contracts. The DPAE, the declaration prealable a l’embauche, the prior hiring declaration for French hires, does not replace SIPSI: a worker declared at home but not on SIPSI is still an undeclared posting in France. Prepare one binder per site, in French or with French summaries, containing the SIPSI receipt, the representative appointment, the service or intra-group agreement, the A1 certificates or social-security proof, the contracts, the time records, the payslips with payment proof, the branch agreement reference, and the client’s verification exchange. Update it every week for long sites. When the inspector arrives unannounced at 7 a.m. on a building site in Saint-Denis, the binder decides whether the visit ends with advice or with a formal report.

Two practical points from Paris and Ile-de-France practice close this section. Paris means the Paris and Ile-de-France DREETS units, multilingual inspection teams on large service and construction sites, and systematic checks around the Olympic-legacy projects, Grand Paris works, and hotel and event peaks. Inspectors in the region routinely ask for the French representative’s physical availability within hours, not days, and for immediate electronic access to time records. Build that availability into the appointment letter: name, French mobile number, French address, backup contact, language capacity, and authority to hand over the file. Second, keep the service contract consistent with the SIPSI story. If SIPSI declares an intra-group posting but the contract shows a direct service to an outside client, or if SIPSI declares two engineers for three weeks but ten workers are on site for three months, the inconsistency becomes the centre of the report. Align the contract, the SIPSI declaration, the A1 dates, and the actual roster before departure, and correct SIPSI promptly if dates or headcount change.

II. What do you risk if the posting fails: back pay, fines and criminal court?

A. How do URSSAF reassessment and administrative fines hit the foreign employer and its French client?

The first bill is administrative, and it arrives per worker. The statute provides that breach by a posting employer of the SIPSI declaration, representative, document or related duties is punishable by an administrative fine under the conditions of the fine article. That is Article L1264-1 of the French Labour Code. The mirror provision for clients provides that the project owner, principal or user company faces the same type of fine when its contractor has missed the declaration duties and the client has missed its own verification duties. That is Article L1264-2 of the French Labour Code. The amounts sit in a single scale. The statute provides: “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 €.” That is Article L1264-3 of the French Labour Code. The fine is imposed by the administrative authority after findings by a labour-inspection control officer, calibrated to the circumstances and seriousness of the breach, the conduct of the offender including good faith, and resources and charges, with a two-year limitation period, recovery like a state claim unrelated to tax or state property, and challenge before the administrative court to the exclusion of any hierarchical appeal. For a foreign founder, the arithmetic is stark: six workers without SIPSI receipts can mean up to 24,000 euros for the foreign employer, plus a parallel exposure for the French client, doubled in case of repetition within two years, capped at 500,000 euros per decision.

The client’s exposure does not stop at its own fine. Under Article L1262-4-3 of the French Labour Code, a project owner or principal informed in writing by a control officer of partial or total non-payment of the statutory or conventional minimum wage owed to a posted worker by its contractor, a direct or indirect subcontractor, or a subcontractor’s partner, must immediately order in writing the subcontractor or partner and its immediate principal to end the situation without delay. Failing regularisation within the regulatory period, the project owner or principal that does not terminate the service contract is jointly liable with the employer for payment of wages, allowances and charges owed, under conditions set by decree in Council of State. In commercial terms, your French client can become the payer of your wage arrears if it keeps you on site after a written warning. That is why sophisticated French buyers now insert posting warranties, SIPSI delivery deadlines, audit rights, withholding mechanics, and termination rights into service contracts with foreign providers. From abroad, treat those clauses as an early warning system: deliver SIPSI, A1 and payslip proof on schedule, or the client will suspend payment and call counsel.

URSSAF runs a separate track focused on contributions, not on SIPSI as such. When workers operate in France without valid home coverage, URSSAF treats the wages as subject to French contributions and issues a reassessment, called a redressement, covering the audit period plus surcharges and late-payment penalties. The Cour de cassation confirmed the breadth of URSSAF document powers for foreign employers in a published ruling of 16 October 2025, appeal number 23-14.039, available at Cour de cassation, 2nd civil chamber, 16 October 2025, No. 23-14.039. The Court held that to investigate or establish concealed-work offences for employees working in France for an employer headquartered abroad, the approved and sworn control officers of social-security bodies verify the declarations the employer must file by collecting from the employer the documents, whatever their form or medium, that show whether the employer holds French social-security affiliation. The lower court was overturned for holding that URSSAF officers lacked power to demand and copy posting-related documents from a company not established in France. For a foreign owner, the message is direct: URSSAF can demand your posting and affiliation file on French soil, and refusal accelerates the reassessment. The controlling legal definitions quoted by the Court state: “est réputé travail dissimulé par dissimulation d’activité, l’exercice à but lucratif d’une activité de production, de transformation, de réparation ou de prestation de services ou l’accomplissement d’actes de commerce par toute personne qui, se soustrayant intentionnellement à ses obligations :” followed by failure to register or to file social-protection or tax declarations. Keep that sentence in mind: operating steadily in France without French declarations is analysed as concealed activity, not as a paperwork oversight.

Procedure from abroad follows a fixed sequence. The labour inspector draws up a report, called a proces-verbal, or an administrative-findings note. The DREETS sends a registered letter stating the alleged breaches, the workers concerned, and the contemplated fine per worker, and invites written observations within a short deadline, commonly fifteen to thirty days. The authority then issues a reasoned fine decision, notifies it, and sets payment terms. The only remedy is the administrative court, the tribunal administratif, of the place of the posting, within two months, with no suspensive effect on recovery unless the judge grants a stay. In parallel, URSSAF sends a letter of observations, then a formal demand, then enforced recovery, with its own social-security litigation path. A foreign company can defend both tracks without flying in every director: appoint a French representative or lawyer with a written mandate, file observations in French with dated exhibits, request a hearing where available, and align the two defences so the labour file and the social-security file tell the same story about dates, headcount, pay and coverage. Paying the fine without observations closes the file but leaves the facts recorded, which doubles the next fine as repetition. Challenging with a thin file wastes the deadline. The winning posture is narrow: admit what is late, prove what is compliant, quantify the arrears paid, and document the corrected SIPSI process for the next posting.

B. When does a false posting become concealed work in criminal court, and how do you regularise from abroad?

A failed posting becomes a criminal file when the inspector or prosecutor concludes that the posting was a cover for stable, habitual work in France without French declarations. The criminal definitions sit in the concealed-work provisions: dissimulation of activity for unregistered or undeclared business, and dissimulation of salaried employment for missing hiring declarations, missing payslips or understated hours, and missing wage or contribution filings. Penalties for individuals include imprisonment and fines, professional bans, exclusion from public contracts, and confiscation, alongside corporate criminal liability for the company, and the criminal court can award damages to URSSAF, the workers, and the trade unions. Two criminal rulings on foreign postings set the frame every foreign owner should know. In Cour de cassation, criminal chamber, 2 March 2021, No. 19-80.991, a Slovak temporary-work structure and its managers were prosecuted for concealed work, unlawful lending of labour, forgery and related counts after postings through certificates later challenged as fraudulent. In Cour de cassation, criminal chamber, 12 January 2021, No. 18-86.757, a Portuguese building company and its manager were convicted of concealed work after numerous postings for French building sites were found not to reflect genuine temporary posting. Both rulings turn on the same European rule about A1 certificates.

That rule is strict and often misunderstood. The Court recalls: “les certificats E101, devenus A1, délivrés par l’institution compétente d’un Etat membre créent une présomption de régularité de l’affiliation du travailleur concerné au régime de sécurité sociale de cet État et s’imposent à l’institution compétente et aux juridictions de l’État membre dans lequel ce travailleur effectue un travail” even where the host state finds that the working conditions plainly fall outside the European cases allowing issuance, citing the Court of Justice of the European Union, 27 April 2017, A-Rosa Flussschiff, C-620/15, as restated in Cour de cassation, criminal chamber, 12 January 2021, No. 18-86.757. The presumption can only be set aside through a defined fraud procedure. The Court adds that where the host institution has asked the issuing institution to review and withdraw certificates in light of evidence gathered in a judicial investigation showing fraudulent procurement or use, and the issuing institution has failed to consider that evidence for review of the issuance, the trial court may set the certificates aside if, on that evidence and with fair-trial guarantees, it finds fraud, citing the Court of Justice, 6 February 2018, Omer Altun, C-359/16. The trial court must first check whether the host institution triggered that review request, must use all legal means to have it triggered if not, and may rule finally on fraud and set the certificates aside only after finding that the issuing institution failed to review them and to state its position within a reasonable time, citing the Court of Justice, 2 April 2020, Vueling Airlines, C-370/17 and C-37/18. For a foreign founder, the operational lesson is concrete: real A1 certificates requested before departure protect the posting, while certificates kept as a shield for permanent French activity collapse once the issuing institution is confronted with the site evidence and stays silent.

Fraud in this context has two limbs that the criminal court must characterise: an objective limb, the failure to meet the posting conditions, and a subjective limb, the intent to circumvent or evade the applicable rules. Objective signs drawn from the two rulings and from inspection practice include a letter-box company abroad with only internal or administrative activity at home, continuous work in France that is habitual, stable and uninterrupted, replacement of posted workers post after post on the same French assignment, absence of genuine recruitment and supervision at home, French clients as the only real business, cash top-ups or understated hours on payslips, and missing SIPSI or late SIPSI combined with missing French wage filings. Subjective intent is inferred from the pattern: backdated contracts, coordinated false time sheets, instructions to hide workers during inspections, or parallel bookkeeping. A single late SIPSI declaration with correct pay and valid A1 certificates points toward an administrative fine. A system of rotating postings with false certificates and French-only activity points toward concealed work. Keep the two tracks separate in your defence papers: fix the administrative breach fast, and reserve the fraud question for precise evidence, not for general statements about good faith.

Regularising from abroad follows a practical order that preserves both the business and the defence. First, freeze the risk: stop new arrivals until SIPSI is current, align the on-site roster with the declared roster, and move the French representative to daily availability. Second, file or correct SIPSI without delay, even late, and deliver the receipts to the French client with a dated cover note, because late compliance still reduces the fine calibration and supports good faith. Third, pay the French wage arrears immediately, with corrected payslips, overtime, leave balances and bank transfers, and keep the proof of actual payment that Article R1263-1 of the French Labour Code requires. Fourth, clarify social security: request or renew A1 certificates where European posting conditions are genuinely met, or register for French contributions and file the missing returns where they are not, with URSSAF. Fifth, answer the DREETS letter within the deadline in French, with exhibits numbered and dated, through a mandated representative or lawyer, addressing each worker and each date separately. Sixth, negotiate the commercial layer: amend the service contract with posting warranties, a SIPSI delivery calendar, a right to suspend postings on inspection findings, and a shared document room. Seventh, decide the structural question for recurring French work: repeated postings of the same roles often cost more than a French hiring solution, whether a French subsidiary with French contracts and DPAE filings, a registered branch, called a succursale, the secondary establishment of a foreign company without separate legal personality, or compliant use of a licensed temporary-work agency. Posting is a tool for temporary assignments, not a substitute for a French workforce.

Conclusion

Sending trusted staff to France from abroad remains an excellent way to win a first French contract, support a new subsidiary, or deliver a specialised project. French law welcomes it, provided the assignment stays temporary, declared, and paid at French standards. File SIPSI before day one, appoint a representative who answers in France, apply the correct minimum wage and working-time rules with full time records, carry valid A1 or agreement-based social-security proof, and keep a site binder the inspector can read without translation help. When the posting fails, treat the administrative fine, the client’s joint liability, the URSSAF reassessment, and the criminal concealed-work risk as four separate fronts with one common remedy: dated filings, paid arrears, and a documented process that prevents repetition. Run from abroad with that discipline, and the posting becomes what it should be: a short, clean bridge between your home team and your French growth.

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