3.2 Declaration of priority 

A declaration of priority from an earlier filing should preferably be made at the time of filing the European application, although this can be done at any time within 16 months from the earliest priority date claimed (see A‑III, 6.5.1). The declaration of priority must indicate the date of the priority application, the relevant state party to the Paris Convention or member of the WTO, and the file number.

A declaration of priority may be corrected within 16 months from the earliest priority date. This time limit cannot expire earlier than four months after the filing date (see A‑III, 6.5.2).