Decision J5/23: Signatures must be handwritten

The Legal Board of Appeal (LBoA) of the European Patent Office (EPO) concluded in the recent decision J5/23 that „signature“ within Article 72 of the European Patent Convention (EPC) demands distinct and handwritten names on the assignment contract, rendering a text string signature insufficient and the assignment invalid.

The decision significantly impacts how the signature requirement within Article 72 of the EPC is interpreted.

Why is this ruling so interesting?
This ruling must be seen in view of the Notice from EPO dated 22 October 2021 concerning electronic signatures on documents submitted as evidence to support requests for registration of a transfer of rights (

This Notice of 2021 states:

“To facilitate communication by electronic means, the Legal Division will accept, as from the date of publication of the present notice, qualified electronic signatures, in addition to handwritten signatures, in respect of evidence filed in support of requests for registration of a transfer of rights and for registration of a licence or other rights.“

In the recent case J5/23, one party used a text string signature on an assignment document. Article 72 EPC mandates written documentation and the genuine signatures of involved parties for such transfers.

In the ruling the LBOA concluded that the 2021 Notice on electronic signatures did not apply to the assignment document as such and only to evidence submitted to the EPO.

In particular the Board stated that:

„As pointed out before, the formal requirements for the conclusion of an assignment contract under Article 72 EPC must not be confused with the requirements for filing a document in proceedings before the EPO.“

In conclusion, the LBOA holds that the term “signature” must be understood as referring to a handwritten depiction of someone’s name, written on the assignment “contract” (Art. 72 EPC).

The practical takeaway is clear: Patent applicants planning to transfer their applications should print, sign, and scan assignment documents to ensure compliance with the rigorous requirements as clarified by the J5/23 decision.