J 0014/94 (Principle of good faith) du 15.12.1994

I. If, during a long period of time, the EPO by its conduct leads the parties and the public to the legitimate belief that no loss of rights has taken place, the EPO cannot later refer to a loss of rights which occurred several years previously without offending against the prohibition of "venire contra factum proprium" and therefore contravening the principle of good faith.

II. In such circumstances, the late payment of a renewal fee may - by way of exception - be considered as having been made in time, if the EPO had not informed the applicant of the outstanding payment, had accepted later renewal fees without objection and had continued the examination proceedings for several years (here: until notification of the communication pursuant to Rule 51(6) EPC).