The board in T 178/84 (OJ 1989, 157) found that in the case of non-payment of the further search fee under R. 46(1) EPC 1973 the subject-matter not searched was regarded as abandoned and accordingly could not be pursued in the parent application. However, in T 87/88 (OJ 1993, 430) it was stated that non-payment could not result in abandonment. According to the latter board, non-payment of further search fees in no way prejudiced the future legal fate of the unsearched parts. R. 46(1) EPC 1973 merely provided that in the case of non-payment of further search fees the search division was to draw up a European search report only for those parts of the application that related to the invention for which the search fees had been paid.
In view of these conflicting approaches, the President of the EPO referred the following point of law to the Enlarged Board of Appeal:
"Can an applicant who fails to pay further search fees for a non-unitary application when requested to do so by the search division under R. 46(1) EPC 1973 pursue that application for the subject-matter in respect of which no search fees have been paid or must he file a divisional application for it?"
In the opinion of the Enlarged Board, given in G 2/92 (OJ 1993, 591), the application could not be pursued for subject-matter in respect of which the applicants had not paid the further search fees. Instead the applicants had to file a divisional application for that subject-matter if they wished to continue to protect it. In the view of the Enlarged Board, it was clear from the procedural system of the EPC that the invention which was to be examined for patentability had to be an invention in respect of which a search fee had been paid prior to the drawing up of the European search report. Part IV of the EPC Part IV Procedure up to grantenvisaged that an application progressed after filing from the search division to the examining division. One object of R. 46 EPC 1973 was to implement this procedure by ensuring that an appropriately extensive search was completed in respect of each individual application before it was examined by the examining division. To this end, in response to an invitation from the search division to pay one or more further search fees in respect of one or more further inventions to which the application related, applicants had to pay such fees if they wished to ensure that one of the further inventions could become the subject of the claims of that application. That was the proper interpretation of R. 46(1) EPC 1973 in context. This confirmed the practice according to T 178/84.
In T 319/96 the initial application lacked unity, but no further search fee was paid. The applicant had argued that, because of the international-type search (Art. 15(5)(a) PCT) carried out by the EPO (in the priority application) for the subject-matter of original claims 4 to 10, it had not forfeited its right to choose and could therefore continue pursuing this subject-matter. It had paid a search fee for each of the two inventions, and two search reports had been prepared by the Office. The board, however, stated that under R. 46(1) EPC 1973 a search fee was to be paid for each further invention if the European search report was to cover that invention. R. 46 EPC 1973 did not provide that a search report from another procedure could be substituted for the European search report. The board referred rather to the possibility under Art. 10(2) RFees (see now Art. 9(2) RFees) of a full or partial refund of the European search fee where the Office has prepared an earlier search report on the same subject-matter. G 2/92 applied also in the present case because in the context of the European procedure only one search report had been drawn up after payment of only one search fee.
In T 631/97 (OJ 2001, 13) the board held that R. 46(1) EPC 1973 on its proper interpretation does not prohibit a review by the examining division of the search division's opinion on lack of unity where further search fees are not paid. A narrow interpretation of R. 46(1) EPC 1973 whereby the finding of lack of unity by the search division is considered as final where the additional search fees are not paid would deprive the applicant of an opportunity to dispute that finding during the examination proceedings and would also unjustifiably restrict the power of the examining division on the question of unity to the subject-matter for which search fees were paid. Thus the board did not share the view held in T 1109/96. The board found the above interpretation of R. 46(1) EPC 1973 to be in agreement with that of the Enlarged Board in G 2/92, and the examination procedure as set out in the Guidelines also to be in line with G 2/92. It noted furthermore, with reference to R. 112 EPC 1973, that the practice of search and examination of international applications where the EPO was elected or designated Office was consistent with the above view.