A decision of the EPO Opposition Division (OD) can be appealed, but only by a party who took part in the opposition proceedings and is adversely affected by the decision.
Under Article 107 EPC, an appeal is restricted to “any party to proceedings adversely affected by a decision,” which means the patent proprietor, an opponent, or a valid intervenor (e.g., an assumed infringer who intervened under Article 105 EPC).
To validly appeal, the adversely affected party must file a notice of appeal and pay the appeal fee within two months of notification of the written decision and must submit the statement of grounds of appeal within four months. The Board of Appeal will then conduct an independent judicial review of the OD’s decision, which may result in the decision being upheld, set aside, or the case being remitted back to the OD for further examination.
