Four potential deficiencies exist with regard to the priority claim, namely:[Art. 90(4); Art. 90(5); ]

Deficiencies (i) and (ii) can only be corrected in accordance with the procedures and within the time limit indicated in A‑III, 6.5.2. Failure to correct either of these deficiencies in time results in the loss of the priority right in question according to Art. 90(5). Further processing does not apply to the time limit under Rule 52(3), since it is excluded by Rule 135(2).

However, where applicants have failed to indicate the file number of the previous application (deficiency (iii)), as required by Rule 52(1), before expiry of the 16-month time limit laid down in Rule 52(2), they are invited by the EPO to provide it within a two-month period under Rule 59. This period can be extended under Rule 132(2) (see E‑IX, 2.3.5, for Euro-PCT applications), but further processing is ruled out by Rule 135(2). Failure to reply in time to this communication results in the loss of the priority right in question according to Art. 90(5).[Art. 90(4); (5); Rule 59; ]

In the event that the applicant has failed to indicate the correct file number of the priority application (deficiency (iv)), a request for correction under Rule 139 can be filed (see A‑V, 3).