noun
transfer ticket
A ticket that allows a passenger to change from one vehicle or line to another without paying an additional fare.
バスから電車に乗り換えるときは、乗継券を運転手から受け取ってください。
When transferring from the bus to the train, please get a transfer ticket from the driver.
乗り換え is the general act of transferring, while 乗継券 specifically refers to the physical ticket used for the transfer.
Compound of 乗り継ぎ (transfer, connecting) and 券 (ticket).