An update from the EPO regarding signatures and signatories

As written by Sophie Butler (Patent Formalities Paralegal) in conjunction with Caroline Marshall (Partner & Board Member - Patent Attorney).

The EPO has recently announced (Article 17, Article 18, Article 22) that they are taking a more relaxed approach regarding signatures and entitlement to sign in relation to the registration of transfers, licences and other rights under rules 22, 23, 24, and 85 of the EPC.

Historically, the EPO has had stringent requirements in place for signatures on documents relating to transfers, etc. However, these requirements changed on 1 April 2024 and the Office has provided directions on how to meet them, stating:

"Contracts and declarations submitted as evidence to support requests for the registration of a transfer of rights under Rules 22 and 85 EPC and requests for the registration or cancellation of the registration of licences or other rights under Rules 23 and 24 EPC may be authenticated by a handwritten signature, a facsimile signature, a text string signature, or a digital signature under the conditions specified by the EPO."

Details of the signature types now accepted are provided below. We expect the new, relaxed rules to be applied to Unitary Patents as well as European patent applications and European patents during any opposition or appeal.

Handwritten Signature: The EPO will continue to accept documents bearing a handwritten signature, in line with its current procedures.

Facsimile Signature: A facsimile signature is a reproduction of a person's handwritten signature. Documents bearing this type of signature may be filed either on paper or electronically using the EPO's electronic filing services.

Text String Signature: 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 their intent to sign. Documents bearing this type of signature may be filed either on paper or electronically using the EPO's electronic filing services.

Digital Signature: The EPO will accept a broader range of electronic signatures on documents submitted as evidence to support requests under the revised Rules.

Digital signatures that use Public Key Infrastructure (PKI) technology, including advanced* and qualified electronic signatures**, will be deemed suitable:

*An advanced electronic signature shall meet the following requirements: (a) it is uniquely linked to the signatory; (b) it is capable of identifying the signatory; (c) it is created using electronic signature creation data that the signatory can, with a high level of confidence, use under his sole control; and (d) it is linked to the data signed therewith in such a way that any subsequent change in the data is detectable.

**A qualified electronic signature’ means an advanced electronic signature that is created by a qualified electronic signature creation device, and which is based on a qualified certificate for electronic signatures.

It will also accept digital signatures that do not use PKI technology if:

  • the documents in question are filed electronically
  • are legible
  • are not infected with a computer virus
  • and do not contain other malicious software

The EPO is not obliged to receive, open or process documents that do not meet these criteria.


The EPO has also changed its position concerning individual entitlement to sign on behalf of a legal person (e.g. a company) regarding supporting documents for requests relating to the rules. Where a person is entitled to sign by virtue of their position within the legal entity, this position needs to be expressly indicated. However, the entitlement will no longer be checked by the EPO.

If you have any questions on these issues, please contact your usual Potter Clarkson representative.