EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Confusion
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure
We were about an hour late of schedule into SJC; while we were on a 1 mile short final on 30L in SJC; we were all set up and ready to touch down; Tower said Air Carrier X ABCD; line up and wait Runway 30R.' We were puzzled for 1 second and looked down at 30R and saw one of our company getting ready to go. Initially thought tower made a call sign mistake; but then during our roll out they cleared us (also Air Carrier X ABCD INBOUND) to cross the right side and contact ground. And they added Air Carrier X ABCD OUTBOUND cleared for takeoff after we cleared both runways. When we were pulling into the gate and ground control contacted us again; and said we need to have our company know and fix this issue; this cannot happen again which may lead into serious incidents!I have seen this happen another time in SFO when company decided to do a tail swap for the outbound due to delay inbound; which led to 2 planes having the same call sign. Suggest Dispatch adding an alphabet to the end of call sign.
EMB-175 Captain reported that during the arrival a duplicate flight number was being used for a company departure.