When an ex-employee appears as an inventor elsewhere: what to do first

Treat the filing as a competing claim, not gossip. Freeze internal records today: invention disclosures, lab notebooks, the employment contract, and any assignment clause. Check the application's filing and priority dates before choosing between an entitlement claim, an opposition, and a quiet approach to the other applicant's counsel. The clock is already running, whether you have noticed it or not.

What EU patent law actually covers here

European patent law does not harmonise who counts as inventor or as owner. That question is decided under the law of the state where the application sits, using that state's own evidence rules. What is harmonised, and worth watching from day one, is what happens once — and if — the disputed filing moves toward unitary protection.

Registration of unitary effect follows Regulation (EU) No 1257/2012. Translation duties once that effect is registered follow Council Regulation (EU) No 1260/2012. Any later dispute over the granted right, including a revocation action built on a disputed inventor entry, sits with the forum created by the Agreement on a Unified Patent Court, for the states that joined it.

What changes once the filing is public

An unpublished application gives you little to react to beyond internal preparation. A published one opens a window: you can read the claims, compare them against your own disclosure records, and see whether the priority date predates or follows the employee's departure.

Deadlines rarely announce themselves. Running clocks are not unique to patent files: When royalties encoded on-chain are ignored and the deadline for a claim can also expire quietly, without anyone flagging the date. Waiting for certainty before acting is the most common way to lose a live option.

What to do first

1. Instruct records or IT to preserve every disclosure, notebook entry, and email tied to the invention, dated as they stand today.
2. Ask patent counsel to pull the published application and compare its claims against your internal disclosure, line by line.
3. Map the application's filing and priority dates against the employee's last working day and contract end date.
4. Route any personal data pulled from company systems through a written data processing agreement; see Data processing agreement: template in detail for the template used for this kind of internal review.
5. Decide the channel — entitlement claim, opposition, or a direct approach to the other applicant's counsel — before contacting anyone outside the company.
6. Calendar every subsequent deadline the relevant office sets, once the channel is chosen.

A partner replies within minutes during business hours once instructed, and a written cost estimate follows within one working day.

Who decides, and on what

In the first instance, the office or court where the application was filed decides entitlement. That decision rests on documentary evidence: dated disclosure records, internal correspondence, and the exact wording of the employment or assignment contract. If the right later becomes a Unitary Patent, a dispute over the granted patent moves to the forum set by the Agreement on a Unified Patent Court, for participating states only.

Three forks worth naming

If the employment contract carries a signed, specific assignment of the invention, the path is comparatively direct: you assert the assignment and ask the office to correct the record. If the assignment was informal, undated, or never signed, the position weakens; the same gap sits behind When the assignment is unsigned but performed and its effect on later inventorship claims, and the fix usually starts with the same evidence trail.

If the invention was made jointly with other staff who remain employed, their statements carry weight and should be taken now, while memory is fresh. If the other applicant is a third party rather than the employee personally, the dispute may run alongside a separate question of who that party actually is.

What this page does not decide

This page does not determine who the true inventor is, does not calculate the specific deadline running on your file, and does not draft an entitlement claim. Where the competing applicant has since incorporated abroad, verifying that counterparty becomes a separate and useful step; see Counterparty in Poland and the deadline that a due-diligence report can actually establish.

Related reading

A comparable timing problem shows up outside patent law too: When a distributor is sued over your product and the notice window that follows works on the same logic — act on the date you learned of the claim, not the date you feel ready.

Verified

Checked against current text as at the publication date below. Sources used: Regulation (EU) No 1257/2012; Council Regulation (EU) No 1260/2012; Agreement on a Unified Patent Court. National entitlement rules are not covered here and are not asserted as harmonised.

FAQ

What is the first step when an ex-employee appears as an inventor elsewhere?

Freeze your internal records the same day: invention disclosures, lab notes, the employment contract, and any assignment clause, before deciding on any external step.

Which deadline is already running?

The application's own filing and priority dates are already fixed. Any office deadline tied to publication or opposition starts from those dates, not from the date you discovered the filing.

Who decides, and on what evidence?

The office or court where the application was filed decides entitlement first, based on dated disclosure records and the wording of the employment or assignment contract. A later dispute on a granted Unitary Patent moves to the Unified Patent Court.

— Vaidas Kudirka, AURELIS