19 CFR 190.154: Filing the entry.

(a) Direct export. At least 6 working hours before lading the merchandise on which drawback is claimed under this subpart, the importer or the agent designated by him or her in writing must file a direct export drawback entry.

(b) Merchandise transported to another port for exportation. The importer of merchandise to be transported to another port for exportation must file an entry naming the transporting conveyance, route, and port of exit. The drawback office will certify one copy and forward it to the CBP office at the port of exit. A bonded carrier must transport the merchandise in accordance with the applicable regulations. Manifests must be prepared and filed in the manner prescribed in § 144.37 of this chapter.