Whether a published European application can be a conflicting application under Art. 54(3) is determined firstly by its filing date and the date of its publication; the former must be before the filing or valid priority date of the application under examination, the latter must be on or after that date. If the published European application validly claims priority, the priority date replaces the 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 prior to publication, the filing date and not the priority date is relevant, irrespective of whether or not the priority claim might have conferred a valid priority right.

Further it is required that the conflicting application was still pending at its publication date (see J 5/81). If the application was withdrawn or otherwise lost before the date of publication, but published because the preparations for publication had been completed, the publication has no effect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 at 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).