Interlining

Also known as interline ticketing, interline booking

Interlining, also known as interline ticketing and interline booking, is a voluntary commercial agreement between individual airlines to handle passengers traveling on itineraries that require multiple flights on multiple airlines. Such agreements allow passengers to change from one flight on one airline to another flight on another airline without having to gather their bags or check-in again. Airlines can also promise free rebooking if the connection is lost due to a delay.