Proof of origin may be an exporter declaration or certificate and can be waived under importing Party law. Proof of Origin may be established by either an origin declaration by an approved exporter or a Certificate of Origin issued by competent authorities, including electronic formats subject to national law; such certificate, statement or declaration is valid for twelve months. Importing Parties may waive the requirement under their national laws, and Proof of Origin must be submitted to the importing Party's customs according to its procedures.