For the foreseeable future, wet-ink signatures are back as the only recommended approach to executing assignments of European Patent applications (EPAs).

In recent case J 0005/23, the EPO has backtracked from its notice issued on 22 October 2021 (referred to here as the October 2021 Notice), which we reported here, in which it had said that it would accept, as evidence supporting a request for a recordal of a transfer of an EPA, either a copy of an assignment executed in wet-ink or executed via qualified electronic signature (QES).

Background facts

In J 5/23, the parties to an EPA assignment signed using text string signatures (see below for what this means) had attempted to record the transfer at the EPO. In issuing a deficiency notice to the request, the Legal Division referred to the October 2021 Notice and informed the applicant that the electronic signatures on the assignment did not fulfil the requirements of a QES. It invited the applicant to re-submit the document in PDF format bearing either QES or handwritten signatures. As the applicant failed to do so, the Legal Division rejected its request for the transfer to be recorded.

The applicants appealed, causing the EPO’s Boards of Appeal to consider the valid form of signature for assignments of EPAs.

Relevant law

The law setting out the requirements for a valid assignment of an EPA is at Article 72 of the European Patent Convention:

“An assignment of a European patent application shall be made in writing and shall require the signature of the parties to the contract.”

Article 72 is supported by the Implementing Regulations, specifically rule 22, which states that:

“The transfer of a European patent application shall be recorded in the European Patent Register at the request of an interested party, upon production of documents providing evidence of such transfer.”

Based on these provisions, we know that an assignment of an EPA must be in writing and signed and that evidence of the assignment must be provided for the EPO to record the transfer, but neither the Article nor the Implementing Regulation provides express requirements as to the form of the document and what is meant by “the signature of the parties”.

What form of signature?

When the EPC was enacted in 1973, digital signature was but a theory (the earliest digital signatures came into use in the late 1970s), and so perhaps it was not considered necessary to specify what was meant by “signature”.  Now, however, there are any number of different signature methods.

The Boards of Appeal considered several of the available types of signature and what was intended by Article 72.  The signature types considered included: wet-ink (or by hand execution), text string signatures, or qualified electronic signatures.

Wet-ink: a signature which has been handwritten, e.g. using “wet-ink”. Wet-ink signatures include no ID verification measures.

Text string signatures: “A text string signature is a string of characters, preceded and followed by a forward slash (/), selected by the signatory to prove their identity and intent to sign” (https://www.epo.org/en/legal/guidelines-epc/2023/a_viii_3_3.html):

//CARPMAELS & RANSFORD LLP//

Text string signatures are acceptable to the EPO on documentation filed using the EPO’s own filing software. This form of signature is often used for procedural matters.

Qualified electronic signatures: A QES is a digital signature which includes identity verification measures, including: 

• Having the ability to uniquely identify and link its signatory to the electronic signature.
• Allowing the signatory to have sole control of the keys used to create the electronic signature.
• Identifying if the data has been tampered with after its accompanying message has been signed.
• Invalidating the signature if signed data has been altered in any manner.

A signature meeting all of the requirements above is an “Advanced electronic signature”.  A QES is all of the above plus the addition of a qualified certificate. This certificate is issued by a qualified trust service provider and it attests to the authenticity of the electronic signature to serve as proof of the identity of the signatory.

Under the relevant EU law, a QES has the same legal effect as a handwritten signature and this is recognized in all member states of the EU.

The Boards of Appeal’s Decision

The Boards of Appeal considered various points including the legal status of the EPC (an international treaty) vis-à-vis the possible instruments to amend or interpret the EPC, including, the October 2021 Notice.  Significantly, the Boards found,

“The Notice’s aim of “facilitat[ing] communication by electronic means” with users is commendable. In the context of Article 72 EPC, however, a notice from the EPO is the wrong means to achieve this. While a notice from the EPO may be a source of legitimate expectations (see J 10/20, Reasons 1.15), it is, as such, only a document providing information. In particular, the Notice is not a legal instrument passed by a competent legislative body … and therefore is not to be taken into account for a systematic interpretation of Article 72 EPC.”

As a result, the October 2021 Notice – with its statement that the EPO would accept assignments executed via QES – was not an authoritative interpretation of the meaning of “signature” under Article 72 EPC.  The most that the October 2021 Notice could do was create “legitimate expectation”, i.e. an expectation on the part of applicants recording assignments at the EPO that the EPO would accept an assignment executed via QES.  The result being that, while the applicant could expect the EPO to accept an assignment executed via QES as evidence to support the recordal of change of applicant, that did not mean that the assignment had been validly executed under Article 72, and so it was possible that such an assignment was not a valid assignment.

Indeed, the Board went on to determine that, “In the absence of any such handwritten signature, an assignment agreement does not comply with the formal requirements under Article 72 EPC and, under Rule 22(3) EPC, has no effect vis-à-vis the EPO.”

Practical advice:

• E-signed assignments dealing with the transfer of EPAs may still be binding on the parties to the contract, this will be a matter for the governing law of the assignment.
• At the time of writing, the EPO has not withdrawn the Notice and so it may still be possible to record an assignment of an EPA executed via QES.
• Our recommendation for anyone executing assignments of EPAs is for the document to be executed by hand. This can be executed in counterparts (i.e. each signatory executing their own copy), and only a scanned copy of the wet-ink signed agreement will be required for filing at the EPO.