In the context of a request under Rule 56(3) the EPO will check that the requirements for the priority claim are met (see III, 6).

Where the applicant files a request under Rule 56(3) (see II, 5.4), the priority claim in question must have been in existence no later than the filing of this request. To this end, the applicant can file a simultaneous request, contained in one single submission:

This is subject to the proviso that the above simultaneous request respects both the time limit according to Rule 52(2) for insertion of a new priority claim (see III, 6.5.1) and the applicable time limit for making the request according to Rule 56(3) (see whichever of II, 5.1 or II, 5.2. applies). If this is the case, then the requirement under Rule 56(3) that priority be claimed is met (see II, 5.4(ii)).

Alternatively, the applicant may file submission (i) earlier (again, provided that it is filed within the time limit according to Rule 52(2)) and then subsequently file submission (ii) (again, provided that it complies with the applicable time limit). However, it is not possible to file request (ii) before request (i), because in this case request (ii) would be filed at a time when there is no priority claim, and it would not meet the requirements of Rule 56(3).