From Census Bureau:
When a shipment is filed to the AES, a system response message is generated and indicates whether the shipment has been accepted or rejected. If the shipment is accepted, the AES filer receives an Internal Transaction Number (ITN) as confirmation. However, if the shipment is rejected, a Fatal Error notification is received.
Fatal Error Response Code: 118
Narrative: Carrier Code Missing
Reason: The Carrier ID (SCAC/ IATA) is missing.
Resolution: The Carrier ID identifies the carrier that transports the goods out of the United States. The Standard Carrier Alpha Code (SCAC) is valid for vessel, rail, and truck shipments. The International Air Transport Association (IATA) code is valid for air shipments.
Verify the Carrier ID and Mode of Transport, correct the shipment and resubmit.
Fatal Error Response Code: 626
Narrative: 1st UOM Code Missing Reason: The Schedule B/HTS Number reported requires a Unit of Measure (1) and Unit of Measure (1) is missing.
Resolution: The Schedule B/HTS Number reported requires a Unit of Measure for 1st Quantity to be reported.
Verify the Unit of Measure for the 1st Quantity, correct the shipment and resubmit.