Legal priority: EBA decision establishes presumption of validity

The reason for a rebuttable presumption is founded on the fact that there are no formal requirements for the transfer of priority rights as well as the presumed common interest of the priority applicant and the subsequent applicant, who must cooperate for priority to be invoked. Therefore, as long as the formal requirements under Article 88(1) of the European Patent Convention for claiming priority have been met (which require the priority applicant to cooperate with the subsequent applicant), the rebuttal presumption will arise.

The rebuttal presumption will apply to any case in which the subsequent applicant is not identical with the priority applicant, including in the case of a plurality of co-applicants of the priority application. For jointly filed – i.e., European patent or Patent Cooperation Treaty (PCT) – applications in which one of the co-applicants is also the priority applicant, the EPO will deem an implicit agreement between the co-applicants.

Although validity of the priority right can still be challenged by third parties in opposition proceedings, the burden of proof is on the challenger, with the presumption rebutted in “rare exceptional cases”. Two examples of “rare exceptional cases” were provided by the EBA; not related to transfer of the priority right, but instead whether “the priority applicant may have legitimate reasons not to allow the subsequent applicant to rely on the priority”. The examples were:

• “Bad faith behaviour on the side of the subsequent applicant”; or
• “The outcome of other proceedings such as litigation before national courts about the title to the subsequent application”.

Challengers of the priority right are not disadvantaged, as “even if a ‘wrong applicant’ claims priority for its subsequent application, this does not necessarily mean that the priority right cannot be relied on”. The EBA then provided the example of a ‘wrong applicant’ claiming…