Ruling on signature validity in patent application assignments

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2025

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

Ruling on signature validity in patent application assignments

Sponsored by

inspicos-400px recrop.jpg
contract-3002431.jpg

Edward Farrington of Inspicos suggests what measures can be taken to ensure the requirements of patent application assignments are fulfilled after a ‘text string’ signature was declared invalid

The transfer of a patent application from one party to another before the EPO is governed by Article 72 of the European Patent Convention (EPC). This stipulates that an assignment of a European patent application shall be made in writing and shall require the signature of the parties to the contract.

A decision of the EPO president, published in the Official Journal of the EPO (OJ EPO, 2021, A42) in May 2021, allowed signatures on documents to be:

  • In the form of an enhanced electronic signature;

  • A reproduction of the signature (facsimile signature); or

  • In the form of a string of characters, preceded and followed by a slash (/) sign (a so-called text string signature).

Ruling on signature requirements

A decision by the Legal Board of Appeal – J5/23 – in September 2023 studied the signature requirement when a patent application is transferred under Article 72 of the EPC. The applicant in J5/23 had filed an assignment document in which one party had signed using a text string signature.

The Legal Board of Appeal studied the Vienna Convention on the Law of Treaties, and definitions of the term ‘signature’ in the three official languages of the EPO. The board found that the term ‘signature’ in Article 72 of the EPC should be understood as requiring the parties to “put their names on the assignment contract in a distinctive manner”. It also construed the signature requirement as a requirement to provide handwritten signatures, resulting in an unambiguous formal requirement.

The signature on the assignment on file, which was in the form of a text string signature, was therefore deemed not to fulfil the requirements of Article 72 of the EPC, and thus the assignment was invalid.

Additionally, the Board of Appeal found that a decision of the president of the EPO from 2021 was not concerned with assignments, and had no bearing on the case in question.

Key takeaway for patent applicants

It is therefore strongly recommended that when patent applications are to be assigned, copies of the assignment are printed, signed, and scanned, to guarantee that they meet the requirements of Article 72 of the EPC.

more from across site and SHARED ros bottom lb

More from across our site

In an exclusive interview, Rouse CEO Luke Minford, Arnold & Siedsma managing partner Steve Duxbury, and Wrays executive chairman Gary Cox discuss plans to build the world’s first ‘truly integrated’ global IP services business
Benjamin Grzimek, partner at Casalonga’s new Düsseldorf office, believes the firm is well-placed to challenge German UPC dominance
A lot of the reporting around the Anthropic settlement misses something critical: it isn’t that relevant to AI training, argues Rebecca Newman at Addleshaw Goddard
Justin Hill and Marie Jansson Heeks, part of an 18-strong team to have joined Crowell & Moring, explain why IP client advice must go beyond only being called upon for patent disclosure
To mark the EUIPO having processed five million EUTM and REUD applications, Managing IP speaks to the most prolific representatives to uncover how they stay at the top of their game
The merger marks Rouse’s second M&A deal within a month, and will provide access to Arnold & Siedsma’s UPC offering
Simon Tønners explains why IP provides the chance to work with some of the most passionate, risk-taking, and emotionally invested clients
The co-leaders of the firm’s new SEP practice group say the team will combine litigation and prosecution expertise to guide clients through cross-border challenges
Boasting four former Spruson & Ferguson leaders and with offices in Hong Kong and Singapore, the IP firm aims to provide fast, practical advice to clients
Partners at three law firms explain why trade secrets cases are rising, and how litigation is giving clients a market advantage
Gift this article