When the same invention is granted to someone else: what it costs to be wrong
The direct cost is losing the window to act while it is still open. Once a rival patent stands granted, every unchallenged day strengthens its position, exposes your shipments to border seizure, and turns a claims comparison you could have done quietly into a dispute fought in front of a court or an office. Being wrong about your own priority is what makes this expensive, not the existence of the rival grant itself.
Basis for a challenge
The basis for contesting a granted patent that covers your invention sits inside the European unitary patent framework. Where a European patent carries unitary effect, its validity is decided under the Agreement on a Unified Patent Court, the single forum competent for revocation actions across the participating states. Unitary effect itself is established under Regulation (EU) No 1257/2012. The language in which the granted claims are published and translated follows Council Regulation (EU) No 1260/2012, and that translation matters directly: a claim compared against the wrong language version is compared against the wrong scope.
None of these acts tell you whether your product infringes the granted claims. They tell you which forum will answer that question, and under what instrument the grant itself exists.
What changes once someone else holds the grant
Silence has a price once the rival patent is granted. If the right holder targets goods entering the EU, they can rely on Regulation (EU) No 608/2013 to have customs authorities detain shipments believed to infringe the granted patent. A dispute that started as a paper disagreement over who invented what first can stop a container at the border before either side has filed anything in a court.
The same caution belongs anywhere a file mixes rights that were never cleared against each other from the start. The pattern repeats when When open source is found inside a deliverable and the ownership chain never matched the claim it was meant to support: the cost of being wrong is discovered late, and it is discovered by the other side first.
What to do, in order
- Pull the granted patent's claims and compare them line by line against your own filing or product, not against a general description of the invention. Assign this to whoever filed or built the product, not to a generalist.
- Fix the evidence of your own dates before contacting anyone. Preserve invention disclosure records, lab notebooks, or commit history exactly as they stand; do not clean them up first.
- Check whether the granted patent carries unitary effect. Where it does, a revocation action runs through the Unified Patent Court, not through a national court.
- Do not approach the other side until the comparison and the evidence steps are both finished. An early contact fixes your position before you know what it is.
- Route the file to a patent professional who can draft an opposition or a revocation action. General counsel can manage the process; they should not be drafting the technical comparison alone.
- Track the office's own published term for the current window. The window exists; its exact length is set and published by the office handling the grant, and last year's term is not a safe assumption.
Who decides, and on what evidence
| Forum | Decides | On what evidence |
|---|---|---|
| European Patent Office | Whether the grant is maintained, amended or revoked, while the opposition window remains open | The grounds raised against the granted claims, matched against the office's own file |
| Unified Patent Court | Whether a European patent with unitary effect is valid, under the Agreement on a Unified Patent Court | Prior art, priority date, and a claim-by-claim technical comparison |
| National court | Disputes over patents without unitary effect, or entitlement disputes between the parties | Filing dates, inventorship records and internal disclosure evidence |
Where the dispute forks
If the granted patent carries unitary effect, the revocation route runs through the Unified Patent Court and nowhere else for that patent. If it does not, the same fight is fought office by office, country by country, and a win in one forum does not carry to the others.
If your own disclosure predates the grant and you can prove it, the fight is about priority. If it postdates the grant, the fight is about scope — whether your product actually sits inside the granted claims at all, which is a narrower and often harder question. The same fork appears outside patents: when When a collection uses third-party artwork explained, the question is again whether the disputed right was cleared before the claim became public, not after.
What this page does not settle
This page does not draft the opposition or the revocation action, does not value the dispute, and does not tell you whether your product infringes the granted claims — that comparison needs the actual file, not a situation page. Where the dispute touches a live commercial relationship, the exposure calculation continues on the reports layer, for example in Counterparty report when a subprocessor is added step by, because a rival granted patent changes the risk profile of any contract built on the disputed technology.
Verified
Reviewed against the current registry snapshot. Primary sources: Regulation (EU) No 1257/2012, Council Regulation (EU) No 1260/2012, the Agreement on a Unified Patent Court, and Regulation (EU) No 608/2013. Handling of the underlying comparison file, including how long extracts and copies are kept, follows Retention: the report, the extracts and our copy step.
Related reading
A related situation, When an injunction application is served in practice, covers the mirror case: what changes once the other side moves for interim relief instead of waiting for a revocation ruling.
Frequently asked questions
What is the first step when the same invention is granted to someone else?
Compare the granted claims line by line against your own filing or product, and fix the evidence of your own dates before contacting anyone on the other side.
Which deadline is already running?
An opposition or revocation window starts running from the date of grant. Its length is set and published by the office handling the grant, and it does not pause while you gather evidence.
Who decides, and on what evidence?
The European Patent Office, the Unified Patent Court, or a national court, depending on whether the granted patent carries unitary effect. Each decides on prior art, priority date and a claim-by-claim technical comparison.