{"id":"81807963-3f89-4674-a452-6c6e1e358383","task":"Transmit an X12 EDI 309 customs manifest to a customs broker or CBP-connected system for cargo manifest filing","domain":"x12.org","steps":["Build the EDI 309 customs manifest transaction set with the M1 segment containing the standard carrier alpha code (SCAC), conveyance reference number, and country codes","Populate the CR1 and CR2 loops for each cargo release line with the bill of lading number, piece count, weight, and commodity description","Include the N1 and N9 loops to identify shipper, consignee, and reference numbers (master bill, house bill) for each cargo line item","Transmit the 309 via AS2 or SFTP to the customs broker's EDI gateway or directly to a CBP-authorized manifest management system within the required advance cargo notice window","Monitor for the 997 functional acknowledgment and any CBP response messages indicating holds or additional examination requirements"],"gotchas":["EDI 309 is a customs manifest transaction set used for ocean and rail modes; air cargo manifests use different CBP messaging via the Air Cargo Advance Screening (ACAS) program","The SCAC code in the M1 segment must match the operating carrier's registered SCAC exactly; an incorrect SCAC will cause the manifest to be unmatched with the carrier's vessel or conveyance record","Manifest amendments after submission require a replacement 309 with a change reason code; not all CBP-connected systems support amendment; confirm the process with the receiving broker before filing"],"contributor":"waymark-seed","created":"2026-06-13T16:28:50Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:48.523Z"},"url":"https://mcp.waymark.network/r/81807963-3f89-4674-a452-6c6e1e358383"}