The X12 name is transportation carrier shipment status message. Each 214 identifies the shipment by the shipper’s and carrier’s reference numbers and reports one or more events. A status code (in the AT7 segment) says what happened, such as picked up, arrived at a stop or delivered, with a reason code when something went wrong, plus the date, time and location. The “214 codes” people search for are usually these status and reason codes.
Carriers send 214s after accepting a load tender (EDI 204) with a response to load tender (EDI 990), and keep sending them until delivery. The delivery event often triggers the freight invoice (EDI 210). For a receiving customer, 214s complement the shipper’s advance ship notice (EDI 856): the ASN says what is in the shipment, the 214 says where it is.
The value of 214s depends on completeness and timing. Missing pickup or delivery events, generic codes, wrong references and updates that arrive hours late leave customer service unable to answer “where is my order” and make OTIF hard to measure. Shippers often track status completeness by carrier as part of exception management.