EPO Standard for Proof of Recording Patent Assignments

By: Catherine Caspar


A European patent application may be transferred for one or more of the designated contracting states.

Article 72 of the European Patent Convention (EPC) is an autonomous provision which exclusively governs the formal requirements of such transfers and defines a high standard of proof for the recordal of assignments. According to Article 72, “An assignment of a European patent application shall be made in writing and shall require the signature of the parties to the contract”. This article thus constitutes harmonised law with respect to the formal requirements for a transfer of a validly filed European patent application and overrules as lex specialis national law which, in general, governs legal acts related to property interests in such applications.

Rule 22 EPC furthermore requires the production of documents providing evidence of such a transfer. Any kind of written evidence suitable for proving the transfer is admissible. This includes formal documentary proof such as the instrument of the transfer itself or other official documents or extracts thereof. Rule 22 applies mutatis mutandis to the registration of a transfer of the European patent during the opposition period or during opposition proceedings.

The supporting evidence does not have to be original or notarized, a scanned copy is sufficient. If the supporting evidence is drafted in a language other than English, French or German, a translation of the document into one of these languages is required.

Concerning the form of the signature, a seal or a rubber stamp impression of a party’s name, whether a natural or legal person, is not sufficient and must be accompanied by a personal signature. Initials or other abbreviated forms are not accepted as a signature.

A transfer can only be recorded on the basis of an official document in accordance with Rule 22(1) EPC if that document directly verified the transfer (J 04/10). For example, it did not suffice if a judgment was submitted which mentioned another document from which it was possible to verify the transfer. Further, documents only establishing the obligation to assign rights but not constituting the assignment itself do not comply with Rule 22 EPC (J 12/00).

If the evidence presented is found to be unsatisfactory, the European Patent Office (EPO) informs the party requesting the transfer accordingly and invites it to remedy the stated deficiencies within a given time limit. We have noted that the EPO has been increasingly requesting supporting evidence of the signatory’s authority to sign on behalf of the legal entity, in particular when the assignment is signed by IP managers or employees.

For example, where one of the parties concerned is a legal person, the assignment may, in general, be signed by any person having the authority to sign on behalf of that legal person. The entitlement of a person signing on behalf of a legal person may be checked by the EPO where there is reason to believe that the person signing is not authorised: in that case, evidence of authority to sign is called for. In order to meet any later challenge or query from the EPO, we recommend putting such supporting evidence in place in advance of executing the assignment. Further, the name and position of each of the signatories as well as the signatures’ dates should be clearly indicated.