How Early Should I Check-In for a Southwest Flight?

When flying with Southwest Airlines, checking in at the right time is crucial—especially because Southwest operates on an open seating policy. This means seats aren’t assigned ahead of time. Instead, your check-in time determines your boarding position, which directly impacts your seat selection. Based on multiple flights I’ve taken with Southwest, both domestically and internationally (to destinations like Mexico and the Caribbean), I’ve found that checking in exactly 24 hours before departure is the smartest move.

Southwest opens its check-in window precisely 24 hours before your flight, and your boarding group and number (A, B, or C) are assigned based on how early you check in. The earlier you check in within that window, the better your boarding position will be, which gives you the best choice of seats—especially if you want a window, aisle, or need extra legroom. I once checked in only 12 hours before a flight and ended up in Group C, which meant middle seat choices at the back of the plane. Ever since then, I set an alarm to check in to the minute when the 24-hour mark hits.

If you're unable to check in manually exactly 24 hours before, Southwest offers a service called EarlyBird Check-In. For a fee (usually $15–$25 each way), the system automatically checks you in before the general 24-hour check-in window, improving your boarding position. I’ve used EarlyBird on business trips when I knew I’d be in meetings during check-in time. While it doesn't guarantee an "A" group spot, it often gets me at least a low B or high A number.

Aside from online or app check-in, you can also check in at the airport. Southwest airport counters and kiosks typically open two to three hours before flight time. However, airport check-in is not ideal if you care about your seat, because by the time you get to the counter, the better boarding groups are often long gone. That said, if you have luggage to check, you should still arrive at the airport 90 minutes to two hours early for domestic flights and at least two hours early for international routes, even if you already checked in online. This gives you time to drop your bags, clear security, and get to your gate without rushing.

In some cases—like traveling with children under six—Southwest offers Family Boarding between Groups A and B. This is helpful if your check-in was late but you're flying with young kids and still want to sit together. Passengers with Business Select fares automatically receive boarding positions A1–A15, and A-List and A-List Preferred members are also given priority.

In conclusion, the best strategy for checking in with Southwest is to do it exactly 24 hours before departure to secure the best seats. If that’s not possible, EarlyBird Check-In is a worthy investment. Whether you’re a casual traveler or a frequent flyer, understanding Southwest’s check-in system can make your trip smoother and more enjoyable from the very beginning.