Automated transshipment permits streamline container movement to inland ports, replacing separate applications and enabling electronic IGM conversion. Automated transshipment uses the ICES EDI system so the SMTP portion of the IGM serves as the transshipment request, eliminating separate carrier applications; carriers must indicate the transporter code in the IGM. Transshipment permit data are transmitted to carrier, transporter, gateway custodian and destination ICES and may be printed. The destination converts the permit into an IGM without fresh filing, the transporter files an electronic container arrival report which is matched to the transshipment message, and a landing certificate is issued to enable closure of IGM lines.