Although it has been a contentious issue in the past, the Enlarged Board of Appeal decision of G 4/19 clearly established that double patenting is not allowed. As the Guidelines for Examination G-IV 5.4 concisely puts it, "two patents cannot be granted to the same applicant with claims directed to the same subject-matter". G 4/19 provides a fuller definition of what is not allowed:
1. A European patent application can be refused under Articles 97(2) and 125 EPC if it claims the same subject-matter as a European patent which has been granted to the same applicant and does not form part of the state of the art pursuant to Article 54(2) and (3) EPC.2. The application can be refused on that legal basis, irrespective of whether ita) was filed on the same date as, orb) is an earlier application or a divisional application (Article 76(1) EPC) in respect of, orc) claims the same priority (Article 88 EPC) as the European patent application leading to the European patent already granted.
Given this clear guidance, one might expect that an examiner will raise an objection if, for example, an applicant files a divisional application with the same claim 1 that has already been granted on the parent application. This would be the clearest case possible of what is not allowed according to G 4/19, and something EPO examiners should be well aware of. As I have discovered recently, however, this does not appear to be the case. I have now found three examples of an applicant filing a divisional application with the exact same claim 1 that has already been granted on the immediate parent application, following which the search opinion has found no objections. These are: EP4092953, EP4184856 and EP4209954. Before you ask, the applications have different examiners but the same applicant. The first of these I have already written about here as it related to the question of when third party observations could have an effect. It turns out that double patenting, once it is pointed out, is in fact a serious enough objection that it can cause examination to be reopened after a communication under Rule 71(3) EPC has issued. This made me wonder whether examiners even check for this when preparing their search opinion for a divisional application. In all of the above three cases, it appears that the examiner did not because the search opinion in each of them simply stated: