EPO case law: Partial Priority and First Application
For reasons of consistency, the rationale of decision G 1/15 (concept of partial priority) must also apply in the context of deciding whether an application from which priority is claimed is the
first application within the meaning of Article 87 (1) EPC. Indeed, just as a priority application and a patent claiming priority therefrom may partially relate to the same invention, the priority application and an earlier application filed by the same applicant may also partially relate to the same invention. In that case, the priority application would be the first application in respect of only that part of the invention which is not the same as in the earlier application and the priority would be claimed validly only for that part of the invention. (EPO BoA 9 November 2017,
T 0282/12).