Yes, one person can check in for multiple people on Southwest Airlines, provided they are all on the same reservation (Confirmation Number). When you enter the confirmation number and last name on the Southwest website or app 24 hours before departure, you will be given the option to select all passengers in that party and check them in simultaneously with a single click. This is a critical "pro-tip" because Southwest’s boarding order is determined by how early you check in; checking in everyone at once ensures the party receives consecutive or very close boarding positions. If members of your group are on different reservations, you will need to open separate browser tabs or use multiple devices to check them in as close to the 24-hour mark as possible. In 2026, Southwest continues to utilize this "open seating" model, making the check-in process the single most important step for families and groups who want to sit together without paying for "Upgraded Boarding" or "EarlyBird Check-In" perks.