Under Art. 109(1) EPC, in ex-parte proceedings the department whose decision is contested must rectify its decision if it considers the appeal to be admissible and well-founded. Inter-partes proceedings are excluded from rectification. However, this does not prevent the department of first instance rectifying its decision where it erroneously revokes, on grounds of non-compliance, a patent it had decided to maintain in amended form (see T 168/03). On expiry of the three-month period under Art. 109(2) EPC 1973, the department of first instance whose decision is contested ceases to be responsible for the matter. Rectification of the decision is then no longer possible (T 778/06).