5.1.1 Requirements 

Whether a published European application can be considered a conflicting application under Art. 54(3) is determined firstly by its date of filing date, which must be before the date of filing or valid priority date of the application under examination, and its publication date, which must be on or after that date of filing or priority date. If the published European application validly claims priority, the priority date replaces the date of filing date (Art. 89) for that subject-matter in the application which corresponds to the priority application. If a priority claim was abandoned or otherwise lost with effect from a date before publication, it is the date of filing date, and not the priority date, that is relevant, irrespective of whether or not the priority claim might have conferred a valid priority right.

In addition, the conflicting application must have been still pending on its publication date (see J 5/81). If the application was withdrawn or otherwise lost before the publication date but nevertheless published because the preparations for publication had been completed, the publication has no effect under Art. 54(3), but only under Art. 54(2). Art. 54(3) must be interpreted as referring to the publication of a "valid" application, i.e. a European patent application in existence on its publication date.

Changes taking effect after the date of publication (e.g. withdrawal of a designation or withdrawal of the priority claim or loss of the priority right for other reasons) do not affect the application of Art. 54(3) (see H‑III, 4.2 for transitional provisions concerning Art. 54(4) EPC 1973 and A‑III, 11.1 and A-III, 11.3 for transitional arrangements concerning non-payment of designation fees for applications filed before 1 April 2009).