1.3 Filing of documents subsequent to the application 

Documents subsequent to the international application may be filed with the EPO as receiving Office electronically or on paper (see A‑II, 1.2).

Priority documents issued in paper form which have to be certified by the issuing authority should also be submitted to the EPO in that form to ensure the validity of the certification. On the other hand, priority documents issued in electronic form may only be filed electronically using OLF or Online Filing 2.0, and provided they have been digitally signed by the issuing authority and the signature is accepted by the EPO; they may not be filed using the EPO Contingency Upload Service (see EPC Guidelines A‑III, 6.7.1). Electronic priority documents may also be filed with the IB using ePCT.