Thu 9th Nov 2023

Wet signatures required for assignment of European patent applications

Service: Patents


Patent Attorney David Roberts explains the Legal Board of Appeal of the European Patent Office’s decision requiring wet signatures on all assignments of European patent applications.

In a decision J0005/23 of the Legal Board of Appeal of the European Patent Office dated 4 September 2023, it was held that documents which assign a European patent application must be signed with handwritten signatures (“wet signatures”). This applies to all parties.


In particular, initially, an electronic copy of an assignment agreement bearing what the applicant termed "text string signatures" was not accepted by the EPO as sufficient to allow the EPO to record the assignment of the European patent application. That decision was appealed to the Legal Board of Appeal.


Based on several dictionary definitions of “signature” and history of the legislature, the Legal Board of Appeal decided that only “wet signatures” meet the requirements of the EPO that the assignment of a European patent application must be made in writing and requires "the signature of the parties to the contract".


The Legal Board of Appeal held that electronic signatures generally on assignment documents were not acceptable to the EPO. This includes simple electronic signatures (such as "text string signatures" as in this case), advanced electronic signatures which are uniquely linked to and capable of identifying the signatory, and qualified electronic signatures which are additionally based on a qualified certificate. It was held that only handwritten signatures result in “a sufficient level of authenticity of the assignment contract.”


So, whilst electronic signatures may be used in the context of filing documents in proceedings before the EPO (which practically all European patent attorneys do every day, for filing European patent applications, responses to EPO examination reports, etc.), this was held not to be sufficient for an assignment document that assigns a European patent application.


Notably, this decision only applies to assignment documents that assign a European patent application. This does not affect the signing of other assignment documents, such as assignments of earlier priority applications. If permissible according to the relevant local law, then such assignment documents can be signed electronically. Indeed, some countries do not require written assignment documents.


This latter point may be relevant given the decision of the EPO Enlarged Board of Appeal dated 10 October 2023 in the consolidated cases G0001/22 and G0002/22 concerning priority claims in European patent applications. It was held there first that the EPO is competent to assess whether a party is entitled to claim priority.


Secondly, it was held that there is rebuttable presumption of priority entitlement. It was noted that a low standard for a valid transfer of priority rights was appropriate in the EPO as national law on assignment of the priority right is not uniform (and indeed written assignment documents are not required in all countries in order to assign the priority right) and the EPO should not require further formalities. It should be borne in mind that in the EPO the right to a file a European patent application (which is subject to national property laws) is treated separately from the right to claim priority (which in the EPO is a right created under the “autonomous law” of the EPC and the Paris Convention and is to be assessed by the EPO), even though the rights typically go together.


For more information on assigning a European patent, please contact David Roberts.


This briefing is for general information purposes only and should not be used as a substitute for legal advice relating to your particular circumstances. We can discuss specific issues and facts on an individual basis. Please note that the law may have changed since the day this was first published in November 2023.


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