In T 158/12 the appellant's view was that there was no article or rule in the EPC which would prevent the applicant from changing from one invention to another – if they were searched – during examination. The board considered, however, that the articles and rules present in the EPC form a statutory system which clearly lead to the conclusion that there was no provision allowing the payment of multiple examination fees for a patent application. The board stated that for one application, only one examination is to be carried out as the result of the single examination fee which has been paid. Having once chosen one invention (or one group of inventions) to be made the subject of examination, this choice could not be altered once examination of that invention has commenced. The board was of the opinion that this approach based on the statutory provisions of the EPC was confirmed in opinion G 2/92. Hence, the appellant's view that the examination of an application could be based on more than one invention was not supported by this opinion of the Enlarged Board of Appeal.

In T 736/14 the board noted that the EPC contains no explicit provisions about how to proceed, if an applicant whose application is non-unitary responds unclearly or in a misleading way to an invitation from the examining division to specify which searched invention it wishes to prosecute further. The board held that in such a situation it cannot be automatically assumed that the applicant selected the invention covered by the main request for examination. Rather, the examining division has to clarify, e.g. via a further communication, which of the searched inventions the applicant actually wants it to examine.