How to Defend a Patent Infringement Lawsuit in Romania (2026): UPC vs National Tactics, Deadlines and Early Actions

Defend patent infringement Romania cases now demand a two-track mindset, because since 1 September 2024 Romania has been a full participant in the Unitary Patent system and the Unified Patent Court (UPC). Whether you have just opened a cease-and-desist letter or been served with proceedings, the first 72 hours will shape the entire outcome of the dispute. The decisions you make about evidence, forum, and early filings can determine whether a claimant secures a swift injunction or whether you retain room to negotiate, invalidate, or defeat the claim. This guide sets out a practical, defendant-focused playbook comparing UPC and Romanian national tactics, mapping the deadlines that matter, and identifying the immediate actions that protect your position.

It is written for in-house counsel, founders, and product counsel who need clarity fast, not a treatise.

Quick action checklist, the first 72 hours to defend patent infringement Romania claims

The opening days of any patent dispute are disproportionately important. Evidence disappears, deadlines run, and an unguarded email can undermine a defence months later. Treat the first three days as a controlled emergency. The goal is to preserve everything, say nothing you cannot stand behind, and buy time to make forum and strategy decisions with proper advice.

Hour 0–24: immediate preservation and triage

The moment a threat lands, your priority is to stop the destruction of anything relevant and to lock down the facts. Do not wait for a lawsuit to be formally served, a well-advised claimant may already be preparing an application for provisional measures. In these first hours, work through the following in order:

• Suspend routine deletion. Immediately halt any automatic document destruction, email purging, or backup rotation that could erase relevant material. Issue a written litigation hold to everyone who may hold relevant data.
• Quarantine files and preserve metadata. Copy the accused product designs, source code, manufacturing specifications, and correspondence to a secure, read-only store. Preserve original metadata, creation dates and authorship can be decisive in a prior-use or independent-development defence.
• Identify the accused product or process precisely. Establish exactly what the claimant says infringes, which patent (or patents) are asserted, and whether they are unitary patents, classical European patents, or Romanian national patents. This single fact drives the entire forum analysis.
• Assess territorial scope. Determine where the accused product is made, sold, marketed, and used. Cross-border activity may expose you to the UPC’s broad reach; purely domestic activity may keep matters in the Romanian national courts.
• Preserve chain of custody. Record who collected what, when, and how. Sloppy collection can render otherwise powerful evidence inadmissible or unpersuasive.

Day 2–3: tactical assessment and forum check

With the immediate preservation done, turn to strategy. This is the window in which patent infringement defense Romania strategy is actually set. Instruct UPC-capable counsel, the profile of lawyer you need is different from a purely domestic litigator, because forum choice now spans two systems. With counsel, run a rapid diagnostic: Is the asserted patent in force? Has it been opted out of the UPC? Is there an obvious invalidity attack or a clean non-infringement position? Should you consider filing a protective letter at the UPC to pre-empt an ex parte injunction? These questions should be scoped, if not fully answered, within 72 hours.

Immediate communications, who to notify and what not to say

Notify your insurers promptly; IP and general liability policies sometimes respond to infringement claims, and late notice can affect cover. Inform senior management and, where relevant, key customers or distributors under privilege. Critically, do not respond substantively to the claimant without advice. Anything you write may be used against you, and an ill-judged admission or an aggressive denial can both cause harm. Where an acknowledgement is needed, keep it brief and reserve all rights.

Romania and the Unitary Patent/UPC, status, scope and what accession means

Romania’s participation in the Unified Patent Court is a defining feature of the current landscape. Understanding what accession actually changed, and what it did not, is the foundation of any sound defence.

What accession means for Romanian companies

Romania deposited its instrument of ratification of the UPC Agreement and became a participating member state, with the UPC and Unitary Patent taking effect for Romania from 1 September 2024. A European patent with unitary effect now covers Romanian territory as part of a single, indivisible right, and the UPC has competence over disputes concerning such patents. In practical terms, a claimant can seek relief before the UPC that extends across all participating member states, including Romania, in a single set of proceedings. For a Romanian defendant, that raises the stakes: an adverse UPC judgment on infringement can produce cross-border injunctive relief rather than relief confined to Romania alone.

Conversely, the UPC also offers a single route to attack the patent through revocation, which can be a powerful defensive lever. The European Patent Office administers the unitary patent and sets out how it interacts with existing national and classical European patent rights.

Transitional rules and opt-out implications

The UPC system includes transitional arrangements that affect classical European patents. During the transitional period, holders of classical European patents may opt those patents out of the UPC’s jurisdiction, so that disputes concerning them remain with national courts. This matters enormously for a defendant. If the patent asserted against you has been opted out, the UPC is not available to the claimant for that patent and you are litigating in the Romanian national courts. If it has not been opted out, the claimant may have a choice between the UPC and national courts during the transitional period.

One of the first checks your counsel should make is the opt-out status of every asserted patent on the UPC register, because it determines which procedural rules, deadlines, and tactics apply to your defence.

UPC vs Romanian national court, jurisdictional test and tactical choice

Where a case is heard changes everything: the speed, the cost, the evidence rules, the reach of any injunction, and the tactical levers available to you. A defendant cannot always choose the forum, but understanding the plaintiff’s incentives and your countervailing options is essential.

When the UPC has competence

The UPC has competence over unitary patents and, unless they have been opted out during the transitional period, over classical European patents validated in participating states. Competence also depends on connecting factors such as where infringement occurred and the defendant’s domicile. Because the UPC can grant relief spanning multiple member states, a claimant seeking to shut down pan-European activity has a strong incentive to litigate there. The UPC operates under a single, detailed set of Rules of Procedure that govern jurisdiction, provisional measures, protective letters, and the coordination of infringement and validity. For a Romanian defendant facing a unitary patent, the UPC is very likely the forum, and the defence must be built around UPC procedure from day one.

When national courts retain competence

Romanian national courts retain competence over Romanian national patents granted through the national route, and over classical European patents that have been validly opted out of the UPC. National proceedings are confined to Romanian territory, which can be an advantage for a defendant whose activity is domestic: the exposure is geographically limited and the procedural environment is familiar. Coordination with the Romanian State Office for Inventions and Trademarks (OSIM, Oficiul de Stat pentru Invenții și Mărci) is central to national invalidity strategy, and Romanian civil procedure, published through the national legislative portal, governs provisional measures and enforcement.

Practical decision matrix: plaintiff incentives versus defendant options

The plaintiff will generally choose the forum that offers the broadest, fastest injunction at acceptable cost. The defendant’s task is to identify where that choice is weakest. If the patent is vulnerable to revocation, the UPC’s central revocation route may actually favour you, because a single successful counterclaim removes the patent everywhere. If the claimant’s real leverage is a threatened ex parte injunction, a protective letter can neutralise the surprise. If the activity is domestic and the patent is a national or opted-out right, keeping the fight in Romania limits exposure. Every one of these levers should be assessed within the first days, not weeks.

Emergency relief and preliminary injunctions, national timelines and UPC procedures

The most urgent threat in most patent disputes is a preliminary injunction. An injunction granted early can force a product off the market before the merits are ever decided, converting a legal dispute into a commercial catastrophe. Resisting emergency relief is therefore often the single most important task for a defendant.

What plaintiffs must prove in Romania for a preliminary injunction

To obtain a preliminary injunction patent Romania claimants must satisfy the standards for provisional measures under Romanian civil procedure. In broad terms, a claimant must show a credible case on the merits, urgency, and a balance of interests favouring interim protection, and courts commonly require the applicant to provide security. The precise standards are set out in national legislation available through the Romanian legislative portal, and the approach of the courts to provisional measures and enforcement is shaped by the case law of the High Court of Cassation and Justice (Înalta Curte de Casație și Justiție).

For a defendant, the key is to attack each element: undermine the merits with a serious invalidity or non-infringement argument, dispute urgency where the claimant has delayed, and demonstrate that the balance of harm favours preserving the status quo.

UPC emergency measures and protective letters

The UPC Rules of Procedure provide for provisional and protective measures, including the possibility of urgent measures and, in appropriate cases, orders made without hearing the defendant. The defensive countermeasure is the protective letter, a pre-emptive filing lodged with the Court in anticipation of an application for provisional measures. A well-drafted protective letter sets out the defendant’s case for why an ex parte injunction should not be granted, so that if the claimant applies, the Court already has the defendant’s arguments before it. Filing a protective letter can be the difference between being shut down without a hearing and securing the chance to be heard.

Drafting defensive evidence and rebuttal

Whichever forum applies, prepare your rebuttal evidence early: technical declarations on non-infringement, prior art demonstrating invalidity, and commercial evidence on the disproportionate harm an injunction would cause. This material must be ready before, not after, the claimant moves.

Key defences, non-infringement, invalidity, exhaustion and licence

A strong defence is rarely a single argument; it is a coordinated set of positions advanced in the right sequence. The two pillars are almost always non-infringement and invalidity, supported where available by exhaustion, prior use, and licence defences.

Invalidity counterclaim strategy and timing

An invalidity counterclaim Romania defendants raise can be transformative, because a patent that is revoked cannot be infringed. At the UPC, revocation can be pursued as a counterclaim within infringement proceedings, producing a single decision effective across all participating states, a formidable weapon where solid prior art exists. In the national arena, invalidity is coordinated through OSIM and the Romanian courts, with effect limited to Romania. Timing is critical: raise invalidity too late and you may forfeit procedural advantages; raise it strategically and you can reshape the entire dispute, converting a defensive posture into an offensive one.

Where a European or unitary patent is asserted, consider whether a central revocation route or a national invalidity action better serves your objectives, taking account of cost, speed, and the geographic scope of your exposure.

Non-infringement defence, building the technical evidence

A non-infringement defence Romania courts and the UPC will take seriously must be grounded in a rigorous claim construction exercise: map each feature of the asserted claims against your product or process and identify where a feature is missing or materially different. Support the analysis with contemporaneous technical documentation, source code, or manufacturing specifications, and a credible independent expert. Non-infringement is often the cleanest defence because it can be resolved without attacking the patent’s validity, and it can defeat a preliminary injunction by undermining the claimant’s case on the merits.

Other defences, exhaustion, prior use and licence

• Exhaustion. If the patented product was placed on the market in the European Economic Area by or with the consent of the patentee, the patent rights in that product may be exhausted, defeating a claim based on subsequent dealings.
• Prior use. Where you were already using the invention, or had made serious preparations to do so, before the relevant date, a prior-use right may protect your continued activity. This is where preserved metadata and dated records become decisive.
• Licence and estoppel. Check for any express or implied licence, cross-licence, or course of dealing that authorises your activity, and consider whether the patentee’s own conduct estops the claim.

Italian torpedo and anti-delay tactics

The “Italian torpedo” is a tactic that a defendant may consider to disrupt an aggressive enforcement strategy, and Romanian defendants operating in the UPC environment should understand both its mechanics and its limits.

Mechanics and examples

The italian torpedo upc concept refers to the strategic use of a first-filed action, traditionally a negative declaratory action for non-infringement in a slow-moving national court, to trigger lis pendens rules and stall a later infringement claim elsewhere. Historically, filing such an action in a jurisdiction known for lengthy proceedings could delay a patentee’s ability to enforce, because a court seised later might be required to stay its proceedings pending the first court’s decision on jurisdiction. The classic target was fragmented national litigation across Europe.

Practical counters and defensive use

The UPC’s design reduces the effectiveness of the traditional torpedo, because the Court operates as a single system with its own rules on competence and coordination, and the UPC Rules of Procedure address the relationship between actions. For a Romanian defendant, the practical questions are twofold. First, is a first-filed national or declaratory action available and worthwhile to shape the forum before the claimant moves? Second, if a claimant tries to use delay tactics against you, what response is available, for example, seeking expedited determination, raising lis pendens correctly, or filing a protective letter at the UPC to secure a hearing.

Any torpedo strategy must be assessed with care and current advice, because the tactic that worked under the old fragmented system may backfire in the unified environment. Treat it as one option to be weighed, not a reflex.

Evidence, disclosure and technical expert management

Patent litigation is won and lost on evidence. In both the UPC and the Romanian courts, the party that has preserved, organised, and presented its technical evidence best has a decisive advantage.

ESI preservation checklist

• Identify all custodians and systems holding relevant electronically stored information, including engineering, sales, and management.
• Preserve source code, design files, manufacturing specifications, lab and test reports, and product development records with original metadata intact.
• Capture relevant email and messaging correspondence, including with suppliers and customers.
• Document the preservation process itself to establish chain of custody and defend against allegations of spoliation.

Managing expert evidence for patentees versus defendants

Choose your technical expert early and choose well. The expert must be genuinely independent, technically authoritative in the relevant field, and able to explain complex matters clearly to a court or panel. For a defendant, the expert typically anchors both the non-infringement analysis and, where relevant, the invalidity case built on prior art. Where a dispute involves a standard-essential patent and a FRAND licensing dimension, expert evidence on the technical standard and on licensing terms must be handled with particular rigour and its cost planned for from the outset.

Costs, security for costs and enforcement considerations

Cost exposure differs markedly between the two systems. UPC litigation, with its pan-European reach and structured fee regime, can carry significant exposure, while Romanian national proceedings are territorially confined and may present a different cost profile. In appropriate cases a claimant may be required to provide security, and a defendant should consider whether to seek security for costs against a claimant with limited assets or based outside the jurisdiction. On the enforcement side, plan defensively: understand how any injunction or damages award would be enforced, consider the role of bank guarantees and customs measures, and watch for cross-border enforcement traps where a UPC judgment reaches beyond Romania.

Enforcement strategy is not an afterthought, it should inform settlement posture from the beginning.

Practical templates and specimen wording

Speed in the first days is easier when you have prepared structures ready to adapt. Have counsel finalise the wording for your specific facts, but know in advance what each document must contain.

Protective letter checklist

A protective letter for the UPC should identify the patent and the likely applicant, set out the defendant’s core arguments against provisional relief (non-infringement, invalidity, lack of urgency, disproportionate harm), attach or reference key evidence, and be lodged before any application is made so the Court has it on file.

Preservation notice template

An internal preservation notice to employees should identify the dispute, instruct recipients to stop deleting relevant material, list the categories of documents and data to preserve, name a contact for questions, and require written confirmation of compliance.

Without-prejudice reply structure

A without-prejudice response to a cease-and-desist letter should acknowledge receipt, reserve all rights, decline to admit any allegation, request specifics (the patent number, the claims asserted, and the basis of the allegation), and set a realistic timeframe for a substantive response, all without conceding anything.

When to settle, negotiation levers and settlement checklist

Not every case should be fought to judgment. The decision to settle turns on the strength of your invalidity and non-infringement positions, the real risk of an injunction, the product’s life cycle and margin, reputational factors, and cost. Where settlement makes sense, the levers include a narrow licence limited to the accused product, a run-off or sell-through licence covering existing stock, a time-limited covenant not to sue, and, where source code or confidential technical material is at issue, an escrow arrangement. A defendant negotiating from a credible revocation threat is in a far stronger position than one negotiating from weakness, which is why building the defence and exploring settlement should happen in parallel, not in sequence.

Next steps and how to instruct counsel

On day one, counsel will typically ask for the cease-and-desist letter or the served documents, the identity and number of every asserted patent, a description of the accused product or process, details of where it is made and sold, and any relevant contracts, licences, or prior correspondence. Send this material under privilege, confirm the deadlines already running, and agree an early strategy call covering forum, protective letters, and preservation. Acting quickly and instructing litigators with genuine UPC capability is the single most effective step you can take.

Appendix: quick reference timeline

The table below summarises the moments that matter most. Exact deadlines depend on the forum and the specific measures sought, so confirm each with counsel against the applicable rules.

Conclusion

To defend patent infringement Romania claims successfully in the current environment, you must think in two systems at once. Romania’s accession to the Unitary Patent and the Unified Patent Court has widened both the risks and the defensive opportunities: a single UPC injunction can now reach across participating states, but a single revocation can also destroy the patent everywhere. The defendants who fare best are those who act within the first 72 hours, preserving evidence, checking opt-out status, instructing UPC-capable counsel, and deploying protective letters and invalidity strategy before the claimant seizes the initiative. Forum choice, timing, and evidence discipline decide these cases far more often than the abstract merits.

Used early and deliberately, the tactics in this guide give a Romanian defendant the best chance of defeating, narrowing, or settling a patent claim on favourable terms.

Sources

1. Unified Patent Court, official site
2. UPC Rules of Procedure
3. European Patent Office, Unitary Patent overview
4. OSIM, Romanian State Office for Inventions and Trademarks
5. Monitorul Oficial, Romanian Official Journal
6. Romanian legislative portal (Just.ro)
7. Înalta Curte de Casație și Justiție, Romanian High Court of Cassation and Justice
8. European Patent Convention (EPC), legal texts