Main infringement action: stages and deadlines
A main infringement action moves through five stages: pre-action assessment, filing, defence and evidence exchange, hearing, and decision with enforcement. In practice, disputes routed through unitary and national tracks take between twelve and twenty months from filing to a first-instance decision, depending on the forum and the complexity of technical evidence.
How the procedure unfolds
Each stage has its own actor, its own paperwork, and its own point of no return. The table below sets out what happens, who drives it, and how long it usually takes in practice.
| Stage | Who acts | Typical duration |
|---|---|---|
| Pre-action assessment | Patent holder and counsel | 2–6 weeks |
| Filing and service | Claimant, then the court registry | 2–4 weeks |
| Defence and evidence exchange | Defendant, then both sides | 3–6 months |
| Hearing preparation and hearing | Court, with both parties | 4–8 months |
| Decision and enforcement | Court, then the prevailing party | 1–3 months |
The point of no return sits at service of the claim on the defendant. Before service, a claimant can still withdraw quietly. After service, withdrawal becomes a matter of record, and it usually carries a cost consequence for the party that pulls out.
What changes once the action is filed
Filing fixes the scope of the dispute. The claims pleaded at this point define what the court will decide; adding a new legal theory later is possible but slows the timetable and invites objections from the other side.
Filing also starts the clock on procedural deadlines for the defence, for disclosure requests, and for any application for interim relief. Missing one of these internal deadlines does not end the case, but it narrows what remains open for argument at the hearing.
What to do before and after filing
- Instruct counsel to map the alleged infringement against the granted claims before drafting anything.
- Assemble the evidence file: the patent certificate, the allegedly infringing product or process, and dated proof of use.
- Decide, with counsel, whether interim relief is needed before the main hearing or whether the timetable can absorb full proceedings.
- File the claim through the competent registry and confirm service on the defendant.
- Track every procedural deadline that starts running after service, and assign one person on your side to own that calendar.
- Prepare for disclosure: identify which internal documents will need to be produced if the other side requests them.
Who decides and where
The forum depends on the patent's protection route: a unitary patent falls under one court structure, a bundle of national patents falls under separate national courts. Either way, a single judge or panel manages the case from filing to decision, and that same body rules on interim relief if one is requested.
The decision issued at first instance is enforceable once it becomes final, subject to any appeal lodged within the applicable window. Enforcement itself is handled by a separate body from the one that decided the merits.
Common forks
If the other side raises a validity challenge as a defence, the timetable usually splits: validity is examined alongside infringement, and the decision on infringement often waits for that finding.
If ownership of the underlying patent is itself disputed — for instance, when a departing party claims to hold rights in the invention — the infringement action typically pauses until title is settled. A related scenario, where a departing founder leaves with a prototype and the register does not resolve the question on its own, is set out here: AI products and models a founder leaves with the.
If the defendant does not engage at all, the court can proceed on the record before it, and a default decision becomes a realistic outcome within the stages set out above.
What this page does not resolve
This page does not set exact statutory deadlines for any single jurisdiction, and it does not quantify costs or fees. It describes the stages, the actors, and the practical timing observed across active files, not the wording of any particular procedural code.
Verified
Reviewed for accuracy as part of the current file cycle. The stage sequence and timing ranges reflect internal case tracking rather than a single cited statute, in keeping with the procedural focus of this page.
For a broader view of how deadlines are tracked across active files, see Delivery statistics, published automatically overview and the deadline.
Where the dispute involves a counterparty based in Spain, a due diligence report can map that party before the claim is filed: Counterparty in Spain in detail.
Related publications
If the first-instance decision does not resolve the matter, the next stage is set out separately: Appeal against a first instance decision step by step.
FAQ
How long does a main infringement action take in practice?
Most first-instance proceedings run twelve to twenty months from filing to decision. Validity challenges, disclosure disputes, or a slow defendant can extend that window; a straightforward, well-evidenced claim can move faster.
Which documents are needed to start?
A claimant needs the patent certificate, a clear description of the alleged infringement, and dated evidence connecting the two. Supporting technical analysis strengthens the filing but is not, by itself, a substitute for the underlying proof of use.
What happens if the other side does not respond?
The court proceeds on the claimant's evidence and pleadings. A default decision is a realistic outcome, though the claimant still has to prove its case to the standard the court applies at that stage.
Next steps
If a coexistence proposal has arrived alongside a related trade mark dispute, the immediate steps are set out here: What to do first in this situation.
If a mark connected to the same portfolio is being challenged as descriptive, the response differs from an infringement action: When a mark is challenged as descriptive: what to.
If a token or digital reference points to a right that was never formally registered, the starting point is different again: When the token refers to an unregistered right and.