As of January 1, 2019, highway carriers entering the U.S. with Section 321 shipments must file an ACE eManifest for that truck.

To report a Section 321 shipment, the carrier must create an ACE Shipment designated as "Section 321" and ensure that it is included in their ACE eManifest.

While a Section 321 shipment differs from a PAPS shipment, the carrier must still provide a unique Shipment Control Number, along with all other required information for an ACE Shipment, including details about the shipper, consignee, and commodity. Additionally, the carrier must include the value and country of origin of the goods in the ACE Shipment.

As with all Informal Entries, no customs broker is involved, and the carrier will not receive an Entry Number for the shipment. At the border, the driver should be ready to present paperwork for the shipment to the Customs Officer.