When the product is redesigned mid-dispute: what to do first
When a patent dispute is already open and the product changes shape, good faith is not the question. The question is whether the new version still falls within the claims that were asserted against the old one. Treat the redesign as a new infringement question in its own right. Freeze evidence of both versions, and tell the court or the opposing side before they find out on their own.
Legal basis
If the patent at the centre of the dispute is a European patent with unitary effect, or a classical European patent litigated under the opt-in system, the procedure sits under the Agreement on a Unified Patent Court. The underlying patent right itself is shaped by Regulation (EU) No 1257/2012 and, for translation arrangements, by Council Regulation (EU) No 1260/2012.
Where the patent falls outside that framework — a purely national patent, or a European patent that was opted out — the redesign question is decided under the applicable national procedure. The forum already seized of the original dispute normally keeps jurisdiction over the amended product, unless a party successfully argues that the change is substantial enough to require a fresh action.
What changes in practice
A redesign does not pause the clock. Interim measures already granted usually keep running against the product description on file at the time they were issued. Whether they extend to the new version is a separate question, and it belongs to the court, not to either party to decide on its own.
Evidence gathered before the redesign can lose weight if the technical solution changed materially. Evidence about the new version may not yet exist in a form a court will accept, which is exactly why the comparison work has to start immediately, not after the next hearing.
What to do first
- Freeze the technical file for both the old and the new version, dated and signed off internally before any external disclosure.
- Commission an updated, claim-by-claim comparison against the new version before showing it to the opposing side or the market.
- Notify the court and the opposing party of the change in writing, ahead of any hearing or deadline that would force disclosure anyway.
- Check whether any interim order names a product description that the new version no longer matches, and flag the gap rather than waiting for it to be found.
- Hold the launch of the redesigned product until the comparison result is in hand, if the launch itself is what prompted the dispute.
Who decides, and by when
The forum depends on which patent is in dispute and where the original proceedings already sit.
| Situation | Forum | Typical deadline |
|---|---|---|
| European patent with unitary effect, or opted-in classical European patent | Unified Patent Court, division seized of the original action | Set by the court's case management order, not a fixed statutory term |
| National patent, or opted-out European patent | National court seized of the original action | Under the applicable national procedure |
| Interim measures already in force | Same forum that granted them | Reviewed on application; no automatic expiry from the redesign alone |
If your situation differs
If the redesign followed a former employee launching a similar product elsewhere, the ownership question and the infringement question run in parallel. They should not be merged into a single file. What to do first in this situation step by sets out that separate sequence.
If the redesign responds to a licensing contract that left no room for a later upgrade, the dispute may sit closer to contract law than to patent law. When the contract has no upgrade path explained covers that scenario on its own terms.
If no interim order is in force yet, the priority shifts. Building the comparison evidence before the opposing side does matters more than compliance with an existing order.
Sources and limits
This page does not decide whether the redesign avoids infringement. That call depends on the specific claims and the specific technical change, and no general page can make it on a reader's behalf. It does not replace a claim chart, and it does not extend or lift an existing interim order — only the forum that granted it can do that.
If the redesign surfaces in a due-diligence or counterparty report and named individuals are affected by that, separate rights apply. If you are named in a report in detail sets those out.
Where an opposing party or a licensee sits in Spain, the country-specific mechanics of what can be checked about them differ from what applies at EU level. Counterparty in Spain step by step covers what such a report can and cannot establish.
Checked: 4 February 2025. Sources: Regulation (EU) No 1257/2012; Council Regulation (EU) No 1260/2012; Agreement on a Unified Patent Court.
Related publications
When damages are demanded without evidence: what to do covers a related pressure point in the same dispute.
FAQ
What is the first step when the product is redesigned mid-dispute?
Freeze the technical file for both versions and commission a claim-by-claim comparison before disclosing the new version to anyone outside the file.
Which deadline is already running?
Any interim order granted before the redesign keeps running against the product description it names. Whether it covers the new version is for the forum that issued it, not for either party.
Who decides, and on what evidence?
The forum already seized of the dispute — the Unified Patent Court division or the national court, depending on the patent — decides on the updated technical comparison, not on the launch announcement or the marketing description.