The requirement of unity under Art. 82 EPC has to be satisfied not only by the patent application as filed but also at later stages of the patent granting procedure, i.e. before the examining division, up until grant of the patent. R. 64(2) EPC (R. 46(2) EPC 1973) refers to the possibility that the examining division might disagree with the search division concerning lack of unity and that the examining division's opinion is decisive in that the latter may order the refund of any further search fee at the applicant's request. It lies within the discretion of the examining division to decide that a patent application lacks unity of invention within the meaning of Art. 82 EPC, even if the search division did not raise a similar objection under R. 64(1) EPC 2007 (R. 46(1) EPC 1973) (T 178/84, OJ 1989, 157). See also in this chapter II.B.6.

According to T 94/91, Art. 82 EPC 1973 clearly provided that European patent applications must satisfy the criteria of unity of invention without any restriction. There was no difference in the EPC 1973 between "a priori" and "a posteriori" lack of unity. It was of no importance whether the non‑unity appeared immediately or only in view of a document found during the search or the examination.

In T 544/88 (OJ 1990, 429) the board ruled that if an applicant, in response to an objection of lack of unity under Art. 82 EPC 1973, filed new claims allegedly relating to an invention meeting the unity requirement, examination should be continued even if the other application documents had not been limited to the subject-matter of those claims. However, the examining division might request the applicant to bring the description and drawings into line with the valid claims (R. 27(1)(d) EPC 1973 as in force until 31.5.1991; cf. subsequent R. 27(1)(c) EPC 1973, now R. 42(1)(c) EPC) and to delete from the patent documents those parts of the description and drawings which did not refer to claimed inventions (R. 34(1)(c) EPC 1973). It would then be necessary to check in each individual case whether such adjustments ought to be deferred until allowable claims were submitted.

In J 24/96 (OJ 2001, 434) the board held that within the framework of R. 46 EPC 1973 it was the task of the examining divisions (and the boards of appeal) to examine whether communications of the search divisions under R. 46(1) EPC 1973 asking for further search fees were justified. R. 46(2) EPC 1973 did not, however, refer to any acts of the search divisions other than communications issued under R. 46(1) EPC 1973. It was therefore not necessary for an examining division to deal in a decision under R. 46(2) EPC 1973 with other objections raised by the applicants in connection with the search, such as the objection that the partial search report was not drawn up in accordance with the Guidelines. The board observed that the examining divisions of course have the possibility of arranging for an additional search to be performed, if they consider a search report delivered by the search division incomplete, but that this had nothing to do with a formal decision issued under R. 46(2) EPC 1973 concerning the refund of further search fees upon request.

In T 188/00 the board pointed out that the review by the examining division under R. 46(2) EPC 1973 had to be carried out having regard only to the facts presented by the search division in its communication under R. 46(1) EPC 1973. Since in most cases objections against lack of unity were raised having regard to the prior art (a posteriori unity objections), this meant that the examining division had to base its review solely on the documents cited in the partial search report and on the specification of the different inventions drawn up by the search division, while taking into account any arguments which the applicant might have submitted in support of his request for a refund. Concerning the analogous protest procedures under the PCT (R. 40.2(c) PCT and R. 40.2(e) PCT and R. 68.3(c) and (e) PCT), the boards of appeal had ruled that these reviews had to be based exclusively on the reasons given in the invitation to pay additional fees, having regard to the facts and arguments submitted by the applicants (W 4/93, OJ 1994, 939). However, in the case in hand the examining division had reasoned that the claims as filed lacked unity a posteriori as a consequence of the finding that claim 1 as filed lacked an inventive step having regard to documents D1 and D4, where the latter document was not cited in the partial search report. Thus the examining division did not review the finding of lack of unity of invention within the meaning of R. 46(2) EPC 1973, but carried out a fresh examination on the basis of a new document D4. The board therefore held that the decision to refuse the refund of a further search fee had to be set aside for formal reasons alone and that the appellant's request for a refund of a further search fee under R. 46(2) EPC 1973 was justified.

In the order of its decision on a requested refund of (further) search fees, the examining division must clearly specify the request which has been decided on, the extent to which it grants that request and orders a refund, and the outcome for any remaining parts of the request. Allowing a separate appeal against its interlocutory decision under Art. 106(2) EPC is a constitutive decision of the examining division which establishes the possibility of challenging the interlocutory decision by way of an appeal, and therefore it too should be included in the order (T 756/14).