The case law of the Boards of Appeal of the European Patent Office does not allow a decision at appeal to put a sole appellant in a worse position. Hence in relation to appeals, the term "prohibition of reformatio in peius" basically means that a person should not be placed in a worse position as a result of filing an appeal. Thus, in general, EPO Boards of Appeal are prevented from going beyond the request of a sole appellant to put it in a worse position that it was before it appealed.

The central case detailing this principle is G 4/93 consolidated with G 9/92.

See also

• Restitutio in integrum