Guide for applicants, Part 2: PCT procedure before the EPO (Euro-PCT Guide)

Where the certified copy of the priority document or, where no copy must be filed (see point 614), the application number has not yet been submitted on entry into the European phase, the applicant will be invited to furnish that copy or number within two months from the date of a notification under Rule 163(2) EPC. This time limit cannot be extended. If the priority document or the application number is not submitted within that time limit, the priority right is lost.

The loss of rights may be remedied by requesting further processing. The request will be granted if within two months from notification of the loss of rights the (certified) copy of the priority document or the application number is filed and the fee for further processing paid. 

If a priority document is missing but the applicant has fulfilled the requirement under Rule 17 PCT in due time, no loss of rights will occur. In such case substantive examination may nevertheless begin, but the decision to grant will not be taken unless the priority document is furnished.