An applicant may pay additional search fees in the international phase if invited to do so by the ISA under Art. 17(3)(a) PCT.
For Euro-PCT applications having entered the European phase, R. 164(1) EPC provides that if the EPO considers that the application documents for the supplementary search do not meet the unity requirements, a European supplementary search report is drawn up on the invention or group of inventions first mentioned in the claims. Where no such supplementary search is to be carried out (i.e. where the EPO drew up the international search report or a supplementary international search report), under the current rule the applicant has no possibility in the European phase to pay further search fees in that application in respect of inventions which were not covered by the international search report or any supplementary international search report. The above situations are in contrast to the former procedure under R. 112 EPC 1973.
R. 164(2) EPC requires the examining division, where it finds that the application documents do not meet the unity requirements, or protection is sought for an invention not covered by the international search report, supplementary international search report or supplementary European search report, to invite the applicant to limit the application to one searched invention.
Unsearched inventions can be pursued in European divisional applications.
In J 3/09, the Legal Board of Appeal confirmed in respect of R. 164 EPC that although the procedure on entry of an application into the European phase where the EPO has acted as the ISA changed with the coming into force of EPC 2000, the responsibility for establishing whether or not the application meets the requirements of unity of invention still ultimately rests with the examining division, and the opinion of the EPO acting as the ISA on lack of unity is not final or binding on the examining division. The board observed that the practice of the examining division in this respect remains as before, noting in particular that to the extent that an objection of non-unity raised by the ISA turns out to be unjustified, the applicant is entitled to have the whole subject-matter of his unitary invention searched. This was also apparent from the wording of R. 164(2) EPC, giving the EPO the power to invite the applicant to limit the application to one invention. This implied that where there is in fact only "one" invention there is no sanction.
The board in T 1285/11 followed this reasoning, adding that the fact that the applicant did not pay further search fees or protest fees in the international phase could not be seen as a tacit agreement with the findings of non-unity of the ISA. As to the wording of R. 164(2) EPC, it could be deduced from the juxtaposition of "an invention not covered by the international search report" and "one invention covered by the international search report" that, for the Rule to be applicable, the non-searched and searched inventions must indeed be non-unitary with respect to one another. In the case in hand, there was, prima facie, a feature which could be regarded as a special technical feature establishing unity between "invention 1" and "invention 2", and R. 164(2) EPC could not be seen as a bar to further prosecution based on the main request.
In considering the applicability of R. 164(2), second half-sentence, EPC, the board in T 507/11 referred to the sanction of G 2/92 (OJ 1993, 591), whereby the application may not be pursued for subject-matter in respect of which no search fee has been paid. In the board’s view, this sanction did not necessarily apply to features disclosed in the original application documents in connection with an invention or group of inventions which has been searched. In the case in point, amended claim 1 contained all the features of searched claims 1 and 2. Protection was therefore still sought for the first, searched invention, now further restricted by features of original claim 13 (attributed by the ISA to another invention and therefore not searched), which, on account of the dependencies in the original claims, had been clearly and unambiguously disclosed. There was therefore no change to an unsearched invention. See also T 442/11 and T 509/11.