Certificate of origin procedures ensure preferential tariff treatment subject to documentary verification and retroactive checks. Procedures require designated Issuing Authorities to issue and retain the certificate of origin in prescribed format, allow pre export verification and documentary checks to confirm originating status, and permit issuance at exportation or within three working days with limited retroactive issuance. Importing customs may deny or suspend preferential tariff treatment, request a retroactive check or a verification visit, and must follow notification and response timelines; records must be retained for at least five years and Parties must cooperate against suspected fraud.