This transaction set communicates carrier interchange agreements for ocean transportation between trading partners. Typically, a carrier or freight forwarder sends the 361 to establish or maintain agreements governing the interchange of containers and equipment with partner carriers. The receiving party uses it to acknowledge, validate, or update the terms of their operational relationship. The ST (Transaction Set Header) segment initiates the document, the N1 (Name) segment identifies the parties involved, and the CI (Carrier Interchange Agreement) segment specifies the core agreement details such as equipment types, interchange locations, and operational responsibilities.

Consider Pacific Shipping Lines sending an X12 361 to Global Container Services to formalize their agreement for container interchange at the Port of Los Angeles. The ST segment marks the transaction, the N1 segment identifies both companies, and the CI segment details which container types (20-foot, 40-foot, high-cube) each party can interchange, designated drop-off points, and liability terms. If specific exceptions or notes apply to the arrangement—such as temperature-controlled container handling procedures—the optional K1 (Remarks) segment provides that clarification. The SE segment closes the transaction, completing the formal agreement record that both carriers can reference during ongoing operations.