1.2. Purpose of the priority right

The right of priority is generally regarded as one of the cornerstones of the Paris Convention. Its basic purpose is to safeguard, for a limited period, the interests of a patent applicant in its endeavour to obtain international protection for its invention, thereby alleviating the negative consequences of the principle of territoriality (T 15/01, OJ 2006, 153, cited in G 1/22 and G 2/22, OJ 2024, A50, point 54 of the Reasons). The rules of the Paris Convention and the self-contained priority system of the EPC should be construed in a manner which ensures that the above-mentioned general purpose is fulfilled as far as possible (T 15/01, OJ 2006, 153, confirmed in T 5/05, cited in G 1/22 and G 2/22, point 54 of the Reasons).

For the person filing a patent application in a state addressed in Art. 87(1) EPC, the priority system means that it has the option to file a bundle of subsequent applications for the same invention in a freely selected group of other territories where each of the later (national or regional) applications may benefit from the priority date of the first application. The priority period of twelve months on the one hand allows for an evaluation by the applicant as to where patent protection should be sought. On the other hand, the clear limitation of the period provides legal certainty to third parties who ought to know the geographical limitations of the patent protection they may be confronted with (G 1/22 and G 2/22, point 55 of the Reasons).