19 CFR 122.79 - Shipments to U.S. possessions.
(a) Other than Puerto Rico. An air cargo manifest shall be filed for aircraft transporting cargo between the U.S. and U.S. possessions. Shipper's Export Declarations are not required for shipments from the U.S. or Puerto Rico to the U.S. possessions, except to the U.S. Virgin Islands or from a U.S. possession and destined to the U.S., Puerto Rico, or another U.S. possession.
(b) Puerto Rico. When an aircraft carries merchandise on a direct flight from the U.S. to Puerto Rico, any required air cargo manifest or Shipper's Export Declarations shall be filed with the appropriate port director at Puerto Rico.