Incheon Airport's official guide places Seoul Station City Air Terminal on AREX Seoul Station B2. It serves eligible same-day international departures from Incheon Airport, restricted to Airport Railroad Express Train customers. Airline check-in and baggage drop are listed 5:20 a.m.–7 p.m.; outbound immigration 5:30 a.m.–7 p.m. Complete check-in at least 3 hours before T1 departure or 3 hours 20 minutes before T2 departure. Airline participation varies, so confirm eligibility. After ticket control, board the express train at B7. Recheck passport, baggage rules and the express timetable.