If an international patent application was filed after the expiry of the priority year, the right to claim priority will only be recognised by the EPO if a request for re-establishment of the right of priority is allowed under the "all due care" criteria.
A successful restoration of the right to priority in the international phase under the "unintentional" criteria (e.g. by the USPTO as receiving office) is not effective in proceedings before the EPO. Therefore, even if the right of priority has been restored by the receiving office, in many cases it is necessary to file a new request for re-establishment of the EPO on regional phase entry.
The EPO applies a strict procedure to re-establishment matters and typically does not allow new facts to be relied upon once the request for re-establishment has been filed. Typically, detailed evidence regarding the circumstances of the late filing must be submitted at the outset to establish that the all due care criteria has been met.
Depending on the circumstances, the deadline for requesting re-establishment and submitting evidence expires on or shortly after entering the European regional phase. If it is intended to proceed in Europe and re-establish the priority right, action should be taken as soon as possible to make sure the deadline can be met.
This brochure provides a summary of the procedure for restoring the priority right of a Euro-PCT application before the EPO.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.