【Southwest^UNDERSTANDING^™︎】How does Southwest 24 hour check in work?Direck!!ConAct$$SIA~~Airlines 24/7-Southwest. Passengers can check in online through the Southwest Airlines website or (+????-????????????✈????????????????????????↞????????) mobile app starting 24 hours before the flight's scheduled departure. +????-????????????✈????????????????????????↞???????? Early check-in ensures better boarding group placement, which can be crucial since Southwest does not assign seats