The notion of a mistake eligible for correction under Rule 139 EPC does not cover the scenario where a declaration of withdrawal reflects the true intention of the applicant, but is based on wrong assumptions.

In J 6/19 the applicant's request to correct the letter withdrawing the application was received at the EPO on the day on which this letter had been published in the European Patent Register. The Legal Board recalled that according to the case law, a request for retraction of a letter of withdrawal was no longer possible if the public had been officially notified of the withdrawal (J 10/87, OJ 1989, 323) and if, in the circumstances of the case, even after file inspection, there would not have been any reason for a third party to suspect, at the time of the official public notification, that the withdrawal could be erroneous and later retracted (J 25/03, OJ 2006, 395). The board noted that the request for withdrawal, which the applicant sought to retract, was unqualified, unambiguous and unconditional and that the request for retraction of the withdrawal would not have been available for file inspection until at least the following day. The board considered that the reasoning of J 25/03, where four days elapsed from the mention of the withdrawal in the European Patent Register to the addition to the file of the request for retraction of the withdrawal, could be applied to the present case. According to this decision the official notification to the public of the withdrawal was a key step and legal certainty would suffer unacceptably if further delay were permitted for retraction of the withdrawal in circumstances, where even after inspection of the file there would not have been any reason to suspect, at the time of the official notification to the public, that the withdrawal, could be erroneous and later retracted. The board in J 6/19 concluded that it was therefore of no relevance to their decision that the request for retraction was received on the same day the withdrawal was published. The time requirement of R. 139 EPC had not been met. In J 7/19 the board explained that an applicant's ability to correct a withdrawal was subject to several conditions specified by the case law of the boards of appeal, the first of which was the existence of a mistake within the meaning of R. 139, first sentence, EPC, which, according to the case law of the boards of appeal, "may be said to exist in a document filed with the European Patent Office if the document does not express the true intention of the person on whose behalf it was filed" (see J 8/80, OJ 1980, 293; J 4/82, OJ 1982, 385). Therefore, mistakes which resulted in a divergence between the party's actual and declared intent were eligible for correction under R. 139 EPC. In the case in hand the applicant had mistakenly believed that the claims of the European application did not differ considerably from the claims of the corresponding Japanese application and decided to abandon the application on the basis of this erroneous assumption. The board found there to be no divergence between the applicant's declaration and its true intention and dismissed the appeal. In the case law of the boards, only errors relating to the declaration, its content or its transmission fell under the notion of a mistake within the meaning of R. 139 EPC. The board explained there were good policy reasons for having this limitation. If the notion of a mistake were extended to also cover a scenario where the declaration correctly reflected a party's intentions, but was based on wrong assumptions, any mistaken assessment of the disclosure of the application, the patentability of the invention, the entitlement to priority, the legal provisions or the related case law would make any withdrawal potentially eligible for correction. This would be detrimental to legal certainty. Where the applicant has made a decision on withdrawal without considering all the relevant circumstances, it must bear the consequences.