Exceptions To Reformatio In Peius At The EPO

In T 2129/14, the EPO Boards of Appeal applied the exception to the prohibition of reformatio in peius established in G 1/99 to allow the patentee, as respondent, to make an amendment which extended the scope of protection of the patent in question compared to the scope of protection maintained by the Opposition Division.

The prohibition of reformatio in peius set out in G 9/92 is the principle that in appeal proceedings a decision must not be reached which puts a sole appellant in a worse position than if they had not appealed. Thus, where a patent is maintained in amended form by an Opposition Division and only the opponent appeals the decision, the patentee, as respondent, cannot amend the claims such that the scope of the patent after appeal proceedings is broader than after opposition proceedings.