Evidence Before Argument: The French Weapon Foreign Patent Holders Forget

The first strategic choice in a patent dispute is not where to sue. It is where to secure the evidence that will make the claim pleadable, quantifiable and commercially credible. A case may ultimately be decided in Paris, before the Unified Patent Court, in London or in the United States; the evidence capable of changing the economics of that case may be sitting today on a server, in an accounting system, at a contract manufacturer or on a production line in France. Increasingly, sitting in France does not mean physically stored there. A workstation in a French subsidiary may be the operational gateway to ERP, CRM, manufacturing, source code or cloud systems containing the relevant evidence.

For a foreign patent owner confronted with a product, a process or a supply chain that touches France, that question should be asked before the statement of claim is drafted. France offers the saisie-contrefaçon, a court authorized measure allowing allegedly infringing products, processes, documents and data to be described, sampled or physically seized before the target has been heard. Its practical force still surprises foreign counsel. An order is obtained ex parte and, without prior warning to the target, a judicial officer may arrive with the patent attorney and, where authorized, a forensic IT specialist capable of identifying and preserving the relevant digital trail. The UPC offers closely related measures for preserving evidence and inspecting premises. Both derive from the same European model: rapid preservation before the merits, possible ex parte execution, safeguards for confidential information, security and a deadline for bringing the action on the merits.

It is therefore no longer accurate to say that France has surprise while the UPC has procedure. The UPC can also act without hearing the defendant, appoint a person to inspect premises, preserve digital media and obtain physical material. In earlier Kluwer papers I have examined national and UPC saisies, the first UPC orders, proportionality, review, later use and trade secrets.1The question left for practice is more concrete: what can the operation actually achieve in a pharmaceutical or SEP dispute, and how should a company prepare when it is on the receiving end?

The answer turns on evidentiary design. In France, the applicant helps shape the technical lens through which the facts are captured. At the UPC, the Court keeps closer custody of the operation and of access to its result. The French advantage is not brute force. It is the possibility of assembling the right technical team, concentrating cost on one operation, linking a hidden technical fact to commercial scale and, where appropriate, using the resulting map in a wider litigation or licensing strategy. Article 145 of the French Code of Civil Procedure broadens the palette again when the missing fact concerns conduct rather than infringement.

Three instruments, three evidentiary failures

A saisie is sometimes described to common-law lawyers as a French Anton Piller order, or as miniature discovery. Neither description survives close inspection, because each instrument answers a different evidentiary failure.

US discovery addresses a universe of information held by the opposing party and reconstructs it progressively. It is adversarial and iterative, reaches documents, electronically stored information and entry onto land for inspection, and is bounded by relevance, proportionality and privilege. The English search order addresses a real risk that important evidence will be destroyed or removed. It is an exceptional in personam remedy, executed under independent supervision and, for digital material, often through an imaging order; it does not authorize forced entry.

The French saisie-contrefaçon addresses a third failure: the patentee cannot observe a technical or commercial reality located on another person's premises. It is a statutory IP evidence mechanism executed by a commissaire de justice (judicial officer), with targeted technical assistance, and it does not invariably depend on proving that the target is likely to destroy anything.2The UPC measure, finally, preserves and inspects evidence relevant to a future UPC action under the procedural custody of the Court.3

The distinction matters commercially. Discovery asks the opponent to explain. A search order prevents disappearance. A saisie records a defined reality at a defined place before that reality has been curated for litigation. The instruments can be used in sequence, but they should not be confused.

The petition is the product

French law allows any person with standing to sue for infringement to seek an ex parte order. The operation is carried out by a judicial officer who may be assisted by experts designated by the applicant.4Those last words are decisive. The applicant selects the technical competence standing beside the officer when the evidence first appears.

The Cour de cassation made the point clearly in 2019. A patent attorney who had already prepared a report on the accused product for the applicant could still assist the judicial officer. The mission was not a judicial expert appointment and was not subject to the same duty of impartiality. The officer authenticates what is found; the patent attorney recognizes the claim feature; the forensic IT specialist locates, filters, copies and preserves the corresponding digital record without altering its integrity.

This division of labor is where the procedure becomes a litigation product rather than a form. In a process patent case, the team must know which intermediate, operating parameter or control screen reveals the claimed step. In a software or connected device case, it must know which repository, firmware branch, log, module reference or access credential matters. Today, much of the operation may take place through screens rather than filing cabinets. The right computer can expose the chain from technical design to product configuration and, through connected business systems, from product configuration to sales. The order sets the perimeter. Preparation determines whether the decisive fact will be recognized when it appears.

The UPC distributes the roles differently. An inspection is carried out by a person appointed by the Court; the applicant may not attend personally, although an independent professional named in the order may represent it. The executing person must offer guarantees of expertise, independence and impartiality and reports to the Court. That model is not weaker. It simply places custody elsewhere. On the French route, counsel asks what the officer and the chosen expert must be authorized to identify. On the UPC route, counsel asks what the Court should instruct its appointee to capture.

Compared with discovery or a search order, a saisie-contrefaçon is often remarkably inexpensive because its cost is concentrated in a single, targeted operation. A focused petition and a short operational team may secure in one morning the technical and commercial facts that broader disclosure would pursue for months. For the right case, the evidentiary yield can therefore be extraordinary relative to the cost. The applicant is buying a brief window of access.

Pharma: evidence that disappears into the product

Pharmaceutical patent cases provide the most obvious, and still underused, application. A finished tablet, vial or biological product may show that a substance is present. It rarely shows how the substance was synthesised, purified, formulated or released. For a process patent, the decisive evidence may disappear into the product before the product reaches the market.

Consider an API process. Subject to a tightly drafted order, the useful evidence may be the master manufacturing instruction, the electronic batch record, reactor temperatures, pressure or pH profiles, in-process chromatograms, raw-material and intermediate lot references, deviation reports, validation records and samples of an intermediate. The patent attorney can identify which records correspond to the claimed sequence; the IT specialist can preserve the relevant manufacturing-execution-system data; the judicial officer can authenticate the link between the physical batch and the digital record.

The same logic applies to biologics and formulation patents. Cell-culture conditions, purification steps, fill-finish parameters, particle-size distributions, polymorphic form, quality-control results or stability batches may answer a question that reverse engineering cannot. A sample taken during the operation can later be analyzed under a protocol designed around the claim. The petition must nevertheless remain a patent petition, not a general raid on a regulatory dossier: the requested categories must be connected to a credible infringement theory and must distinguish commercial manufacture from activities that may fall within a regulatory exemption.

The seller is not always the right address. French law permits the measure to be carried out “in any place”, subject to the order and proportionality.5In practice, the useful site may be a contract manufacturing organisation, an analytical laboratory, a distributor, a logistics provider or the French subsidiary that holds the batch and ERP records. This is often the first practical insight that changes the case: go where the evidence is, not merely where the product is sold.

SEP: from implementation to licensing economics

SEP lawyers rarely think first of a saisie-contrefaçon. The reason is understandable. Essentiality and infringement are often argued by mapping the claims to the standard, while compliance material or a product sample may establish implementation. That approach can prove the technical proposition and still leave the commercial case strangely abstract.

A carefully designed operation can identify which products actually implement the standard, through which chip, module, firmware or software release, since which date and under which SKU. Conformity reports, bills of materials, integration documents, test logs, release records and device-management data may be more useful than the external product alone. The point is particularly concrete for connected medical devices and diagnostic equipment, where the cellular or Wi-Fi implementation may sit several layers below the branded product.

The overlooked value is commercial. Once the technical identifier is known, the same operation may connect it to ERP, CRM, invoice or sales ledger fields showing French units, revenues, customers and deployment dates. A FRAND rate is not generated mechanically from turnover, and a French saisie is not a free worldwide audit. But implementer figures are indispensable to test the royalty base, volume tiers, past use exposure, product mix and the total value produced by a proposed rate. Even where the operation establishes only a reliable French minimum, it can identify the database fields and custodians around which later disclosure or a licensing audit should be organized. Those figures do not themselves determine a FRAND rate. But by reducing the informational asymmetry between the parties, they may give subsequent licensing negotiations a more concrete economic basis and sometimes make agreement easier before a court is asked to determine the terms.

The practical sequence is simple: standard feature, technical implementation, product version, SKU, units and revenue. That chain turns a debate about an abstract rate into a bounded licensing position. It may strengthen an injunction or damages case; it may also show that the relevant implementation is limited, recent or absent. A good saisie does not merely create leverage. It prices the decision whether to litigate, license or walk away.

From technical identity to commercial scale

On paper, the French and UPC texts authorize much the same objects of preservation. French law permits detailed description, sampling, physical seizure of allegedly infringing products or processes and seizure of related documents, materials and instruments. The UPC expressly adds digital media, data and access passwords. Neither measure is limited to photographing a product.

A properly framed order may therefore reach technical drawings, source code, software releases, design files, test reports, manufacturing instructions, process parameters, quality control records, batch documentation, bills of materials, supplier and customer references, ERP extracts, invoices and sales ledgers. These materials can answer three questions at once: the origin of the infringement, meaning where the accused product, process or functionality comes from; its substance, meaning what it actually is and how it works; and its extent, meaning the products, quantities, customers, dates and revenues through which the infringement translates into commercial exposure. They do not authorize a search of the undertaking's entire information system. Categories, sites, periods and search methods must remain connected to the alleged infringement and proportionate to the evidentiary objective.

The commercial value is not theoretical. In a judgment of 31 March 2023, the Paris Tribunal judiciaire found that computer files obtained during a saisie established slightly more than EUR 9 million in turnover for the accused products over five years. Applying a royalty rate to the turnover proved by the operation, it awarded an interim payment of EUR 633,000 and ordered further certified production because the infringement had continued.6The operation had converted an allegation into a quantified litigation and settlement position before the final accounting exercise was complete.

The most valuable operation usually connects a technical identifier to a commercial database. A source code module, batch reference or firmware version becomes materially more useful when it can be traced to dates, customers, quantities and turnover. In a modern company, those two worlds may be only a few clicks apart on interconnected systems. A technically focused seizure can therefore move, within the limits of the order, from the feature that proves infringement to the records that establish its commercial scale. That connection changes settlement dynamics before the damages phase. It can also narrow later US discovery from “all documents relating to the accused functionality” to identified code branches, batch records, fields and custodians. France supplies the map; discovery can reconstruct the journey.

One of the most unusual strategic features of the French route is that the evidentiary record is not, by statute, confined to the French litigation for which it was obtained. Subject to the terms of the order, confidentiality restrictions and the procedural rules of the receiving forum, material secured in France may therefore be capable of being deployed before the UPC or another national court, or used to focus subsequent US or other disclosure. A French record may in that sense be more portable than a UPC record, because Rule 196.2 ties the outcome of a UPC preservation measure by default to the corresponding UPC merits proceedings, while the French patent provisions contain no equivalent express single case restriction. France can therefore sometimes be the place where evidence is secured even when France is not the place where the principal dispute will ultimately be decided. Portability is not automatic admissibility. The merits action keeping the operation alive, access restrictions, trade secret orders, data protection, privilege and the receiving court's rules must all be mapped before cross border use.

The target’s side: secrecy, custody and readiness

The same procedure that is attractive to a patentee can be dangerous to the target. French law allows provisional sequestration of seized material to protect trade secrets, and the Cour de cassation has held that this dedicated mechanism is the prescribed route for doing so.7Secrecy is not a veto on evidence. It is a problem of identification, custody, triage and controlled access.

In my experience, pharmaceutical companies are more likely to have inspection protocols because regulatory visits and controlled technical dossiers are familiar. Electronics and SEP businesses often do not think about patent-seizure readiness, although their source code, license comparables, customer prices, standards strategy and security credentials may be among their most sensitive assets. The first time these categories are mapped should not be while a judicial officer and an IT expert are already imaging systems.

A useful readiness review is practical rather than theatrical. It identifies the repositories containing crown-jewel data, names the counsel, IT and business decision-makers who must be called, separates personal and legally protected material, prepares a method for identifying trade secrets contemporaneously, and explains how to request sequestration or a confidentiality circle without obstructing lawful execution. It also ensures that logs and objections are preserved for a later request to modify or retract the order. The best defense starts before reception calls upstairs.

The UPC begins from a different institutional position. The person executing the measure reports to the Court; access may be restricted to specified persons; and the result is, by default, confined to the corresponding merits case. In Progress Maschinen v AWM and Schnell, the Court of Appeal treated disclosure as inherent in the preservation request but still required an adversarial confidentiality process, potentially limiting access to authorized representatives. A UPC measure therefore has at least three stages: grant, execution and access.

The clocks also differ. In France, the applicant must bring the merits action within twenty working days or thirty-one calendar days, whichever is longer, from the operation itself.8The deadline does not wait for a claim chart or secrecy dispute. At the UPC, the Court specifies the starting date with regard to the report, and Progress Maschinen held that the period ran from access under the disclosure order, or final refusal of access, rather than from execution alone.9France gives the applicant more influence at capture but less room for open-ended exploration.

Privilege must be kept analytically separate from trade secrets. The forthcoming French regime for qualifying in-house legal consultations will create another protected category when it enters into force; it is conditional and is not a substitute for a trade-secret protocol.10Applicant and target counsel should therefore design the secrecy architecture with the same care as the technical search.

Article 145: when the missing evidence is held by a person

The saisie-contrefaçon is tied to the proof of patent infringement. Article 145 of the French Code of Civil Procedure is broader. Before proceedings, any interested person with a legitimate reason may seek legally admissible measures to preserve or establish facts on which a potential dispute may depend. The measure may be sought in summary proceedings or, where the departure from adversarial process is specifically justified, ex parte. It must be circumscribed in time and object, necessary and proportionate; it cannot become a general investigation. That can make Article 145 a remarkably direct evidentiary tool: the measure can be designed around the person, premises or systems where the relevant facts are actually held rather than around the formal defendant to a future patent infringement claim.

That makes Article 145 particularly useful where the missing evidence concerns conduct around the patent: FRAND negotiations, discrimination, misuse of confidential information, the role of a former employee, the location of a key custodian, or the decision-making behind parallel proceedings. A saisie-contrefaçon captures the technical and commercial reality of infringement. Article 145 can capture the broader facts that explain how the dispute was conducted.

The Thales/Philips litigation provides the clearest SEP illustration. Thales alleged abusive conduct in negotiations over Philips' GSM, UMTS and LTE SEP portfolio. It obtained an order of 15 November 2021 authorizing the search and seizure of documents and emails linked to US proceedings handled from France by Philips' principal IP and licensing counsel. The measure was executed on 14 December 2021 at Philips France's headquarters. The Paris court refused to retract the order and later organized expert triage and a confidentiality circle to exclude protected and personal material.

The publicly filed application is even more instructive. Because the relevant counsel appeared to be teleworking, Thales presented parallel requests designed for simultaneous execution at the company and at her home. The published French decision records execution at the corporate site, not at the residence. It should therefore not be cited as proof that the home measure was executed. It does show the architecture: Article 145 can be designed around the actual custodian and, in an exceptional case, a private residence, provided necessity, privacy and proportionality are addressed with precision.11

Sometimes the right strategy is sequential: a patent saisie at the plant, server or accounting site to establish implementation and scale, combined with an Article 145 measure aimed at negotiation conduct or another non-infringement fact. Sometimes the UPC is cleaner, particularly for a unitary patent, evidence outside France but within UPC territory, or a merits action intended to remain within a single court-controlled chain. The UPC may also order production of banking, financial and commercial documents under Article 59.12

The destination of the evidence decides the drafting. Which title is asserted? Where is the missing fact? Who must recognize it on the spot? Which merits action keeps the measure alive? Who may see the result? Where must it later be used? For a classical European patent, the UPC transitional regime and any opt-out must be mapped before execution. This is why the operation should not be handed to French counsel as local procedural paperwork after the wider strategy is fixed. The evidence map is the wider strategy.

The evidence map before the knock

The question for foreign counsel is whether a French site, subsidiary, contract manufacturer, workstation, server, production line, accounting system or key custodian provides access to evidence capable of changing the economics of a wider dispute.

Where that evidence exists, a saisie-contrefaçon can provide an unusually concentrated way to secure it: a public officer to authenticate, a patent attorney to recognize the relevant feature and, where needed, a forensic IT specialist to preserve the digital trail. An ex parte order can thus give the applicant, in a matter of hours, a court authorized window onto technical and commercial evidence that would otherwise remain entirely inside the competitor's organization. In pharma, that may reveal the process that has vanished into the product. In SEP litigation, it may connect implementation to units and revenue. The resulting record may then inform proceedings in France, before the UPC or elsewhere, subject always to the rules governing its disclosure and admissibility. On the target side, a readiness protocol may protect the secrets that should never flow freely to a competitor.

A good operation does four things at once: it identifies the hidden fact, ties that fact to commercial scale, anticipates secrecy and fits the merits route that follows. Its strength is both procedural and operational: surprise creates the window, but preparation determines what comes through it. That is not a form. It is a field operation designed by counsel, the judicial officer, the patent attorney and the IT specialist before anyone knocks on the door.

The right question is therefore not simply “France or the UPC?” It is what evidence must be frozen, by whom, at what cost, under what secrecy architecture and for use where. Forum selection should follow that evidentiary design, not precede it.

• 1See, among earlier Kluwer Patent Blog coverage, Matthieu Dhenne, “An occasion to seize!” (25 January 2021); “Saisies-contrefaçons and trade secrets: developments in France since the 2018 reform” (7 May 2022); “The other ‘saisie’: the saisie conservatoire in France to recover evidence for foreign proceedings” (14 March 2023); the four-part “UPC ‘saisie-contrefaçon’” series (14 March to 3 April 2024); “Is saisie-contrefaçon dead? Long live saisie-contrefaçon?” (22 October 2024); and “The UPC Didn’t Kill Parallel Litigation—It Weaponized It” (7 April 2026).
• 2CPI, art. L. 615-5, paras 1-2; French Code of Civil Procedure (CPC), arts 493-498. The patent statute does not condition the measure on a risk of destruction, although an ex parte application must justify departure from adversarial process.
• 3UPCA, art. 60; Rules of Procedure of the Unified Patent Court (RoP), rr. 192-199.
• 4CPI, arts L. 615-5 and R. 615-4.
• 5CPI, art. L. 615-5 (“en tout lieu”). The statutory reach does not dispense with a precise order, connection to the alleged infringement and proportionality.
• 6

  Tribunal judiciaire de Paris, 31 March 2023, RG No. 20/02638 (EP 1 186 719), paras 86–88, 93–94 and operative part: saisie-obtained computer files established minimum turnover of EUR 9,049,472.46; the court awarded EUR 633,000 provisionally and ordered certified worldwide sales and turnover data because the saisie accounting search had been limited to France. Confirmed on these points by Paris Court of Appeal, 9 January 2026, RG No. 23/19521.

• 7CPI, art. R. 615-4, final paragraph; French Commercial Code, art. R. 153-1; Cour de cassation, Commercial Chamber, 1 February 2023, no. 21-22.225, ECLI:FR:CCASS:2023:CO00095, published in the Bulletin and Annual Report.
• 8CPI, art. R. 615-6.
• 9

  UPCA, art. 60(8); RoP, r. 198.1; UPC Court of Appeal, Progress Maschinen & Automation AG v AWM Srl and Schnell SpA, 23 July 2024, UPC_CoA_177/2024, APL_20002/2024, ORD_36778/2024, paras 16 and 20.

• 10Law no. 2026-122 of 23 February 2026, art. 1, creating art. 58-1 of Law no. 71-1130 of 31 December 1971. The regime protects qualifying in-house legal consultations against seizure in civil, commercial and administrative matters under detailed conditions; art. 4 provides that it enters into force on a date fixed by decree and no later than 1 February 2027.
• 11

  Thales SA, Requête aux fins de mesures d’instruction in futurum, 9 Nov. 2021, paras 158–175, 190–203, Exs A–B to Philips’ Motion to Reopen Record, USITC Inv. No. 337-TA-1240. The application contemplated parallel measures at Philips France Commercial’s premises and a private residence, but the materials cited establish execution only at the company’s Suresnes headquarters; see TJ Paris, 13 Sept. 2022, RG No. 22/00651, paras 4–5.

• 12UPCA, art. 59(1)-(2).