R. 40(1)(b) EPC provides that the date of filing of a European patent shall be the date on which the documents filed by the applicant contain, inter alia, 'information identifying the applicant or allowing the applicant to be contacted'. (The latter option was added in the EPC 2000). The requirement for information identifying the applicant was previously contained in Art. 80(c) EPC 1973.

In J 25/86 (OJ 1987, 475) it was pointed out that the requirement under Art. 80(c) EPC 1973 for "information identifying the applicant" was to be considered as having been met whenever it was possible to establish beyond reasonable doubt the identity of the applicant on the basis of all data contained in the documents filed by the applicant or his representative.

As noted in this chapter IV.A.4., under Art. 60(3) EPC the EPO assumes the applicant to be entitled to the European patent.

In T 948/10 the EPO was wrongly informed that the applicant company's name had changed, and amended it accordingly. As neither the appellant's representative nor the examining division/Client Data Registration department had had any reason to believe that the party to the proceedings was anyone other than the original applicant, the board found that this error did not invalidate the procedural steps taken taken by the applicant before the first-instance departments ("falsa demonstratio non nocet"), and that the EPO should correct the mistake itself.