We have previously noted that assignments executed solely by the assignor (e.g., an inventor when assigning rights to their employer) are technically deficient in Europe due to a difference between U.S. and European law. In particular, Article 72 of the European Patent Convention (EPC) requires assignments to bear “the signature of the parties to the contract,” while contract law in the U.S. considers a contract signed only by the conveying party to be valid for this type of one-way conveyance.

Despite the technical requirement of the EPC, the European Patent Office (EPO) has not strictly enforced the law in view of the less demanding requirements in the U.S. and elsewhere. Starting November 1, 2016, however, a new version of the EPO’s Guidelines for Examination will take effect and the requirements of Article 72 will be enforced. This means that any new assignment document for a European patent application must be signed by both the assignor and the assignee. Previously recorded documents will not be impacted.

Accordingly, practitioners who file in Europe should consider having assignments executed by both parties starting immediately. Note that there are possible work-arounds for cases that have already been assigned with only an assignor’s signature but have not yet been recorded. These can include, for example, use of a confirmatory assignment executed by both parties or a declaration executed by the assignee that references the prior assignment. In addition, the updated guidelines apply only to original European patent applications. Where a European patent application claims priority to, for example, a U.S. application, requirements of U.S. law will continue to govern.