- The Southwest Airlines boarding process is unique and efficient, designed to keep things simple and fast. Instead of assigned seats, passengers are given a boarding group (A, B, or C) and a position number. Your boarding group and position determine when you’ll line up and board the plane. Seats are available on a first-come, first-served basis once you're on board. You can improve your boarding position by checking in early, purchasing EarlyBird Check-In, or holding elite status. Families with children under six can board after group A. The open seating system encourages passengers to board promptly and pick seats quickly. It’s smart to check in exactly 24 hours before your flight for the best spot. Visit: https://www.airlinesticketoffice.com/blog/southwest-airlines-boarding-process/