For the purposes of obtaining a date of filing it is not necessary for the European application to contain any claims. The presence of at least one claim is nonetheless a requirement for a European application according to Art. 78(1)(c), but a set of claims can be provided after the date of filing according to the procedure described below.

The EPO will check whether at least one claim is present in the application. If this is not the case, the EPO will issue an invitation under Rule 58 inviting the applicant to file one or more claims within a period of two months. If the applicant fails to do so within this period, the application is refused according to Art. 90(5). The applicant is notified of this decision according to Rule 111. Further processing for failure to observe the time limit under Rule 58 is excluded by virtue of Rule 135(2). The applicant may, however request re-establishment according to Art. 122 and Rule 136 or may appeal.

Where the application documents as originally filed did not include at least one claim, the applicant may also file claims of his own motion after the date of filing, but before the EPO invites him to do so under Rule 58. In this case, no communication under Rule 58 will then be issued.

If the applicant does supply a set of claims in response to the invitation under Rule 58, the claims so filed must have a basis in the application documents (description and any drawings) provided on the date of filing (Art. 123(2)). This requirement will first be checked at the search stage (see B-XII, 2.2).

If the application was filed by means of a reference to a previously filed application in accordance with Rule 40(3) and the applicant indicated on the date of filing that the claims of the previously filed application were to take the place of claims in the application as filed, (see II, 4.1.3.1), then, provided the previously filed application also contained claims on its date of filing, claims were present on the European date of filing and no communication under Rule 58 will be sent.

The above procedure also applies to divisional applications and applications filed in accordance with Art. 61(1)(b).