Each major airline handles its booking window a bit differently. Here's a closer look at how far ahead you can book with each of the biggest U.S. carriers specifically.
American Airlines
American opens bookings approximately 330–331 days before departure, in line with the broader legacy-carrier standard. This applies to both domestic and international routes operated directly by American, though partner airline bookings through American's AAdvantage program can sometimes follow a different schedule depending on the partner's own release pattern.
Delta Air Lines
Delta follows essentially the same window as American — around 330–331 days out. Delta's SkyMiles award bookings generally track closely with this cash-fare window too, though Delta has been known to release some award inventory slightly ahead of or behind the standard mark depending on the route and season.
United Airlines
United also opens bookings roughly 330–331 days before departure, matching the pattern of the other two major legacy carriers. United's MileagePlus award seats typically follow a similar timeline, with the airline's dynamic award pricing model meaning the best redemption rates (rather than a fixed "saver" chart) can appear or disappear based on demand at any point within that window.
Southwest Airlines
Southwest is the clear outlier among major U.S. carriers. Rather than a fixed number of days before departure, Southwest releases its flight schedule in periodic blocks — each release typically extends the bookable window by roughly 6–9 months. This means Southwest's "how far ahead can you book" answer changes throughout the year and isn't predictable the way it is for American, Delta, or United. Checking Southwest's own booking page directly for your target dates is the only reliable way to know if a specific flight has been released yet.
JetBlue
JetBlue opens its booking window 331 days before departure, essentially matching the legacy carrier standard, with the airline's system updating daily as new dates roll into range.
Alaska Airlines
Alaska generally follows the same 330–331 day window as American, Delta, and United for cash fares. Where Alaska differs is in some of its partner award bookings, which can open as far as 365 days out — a full year — for certain partner airlines within Alaska's Mileage Plan program. This makes Alaska worth checking specifically if you're trying to book an award seat as early as technically possible.
Spirit and Frontier
Both budget carriers tend to open bookings somewhat later than the legacy standard — generally somewhere between 8 and 11 months out, with the exact timing varying more by season and specific route than it does for American, Delta, or United. If early booking matters to you and you're flying one of these carriers, expect a narrower window and check the airline's site directly rather than assuming the legacy 330-day standard applies.
A Note on International Carriers
Non-U.S. airlines vary more widely than domestic carriers. Some open bookings as far as 360–365 days out, which matters most to travelers chasing premium cabin award seats, since the best availability at those cabin levels tends to open right at the earliest edge of the window and disappear quickly afterward.
Comparing the Major Airlines at a Glance
| Airline | Typical Booking Window |
|---|---|
| American | ~330–331 days |
| Delta | ~330–331 days |
| United | ~330–331 days |
| JetBlue | 331 days |
| Alaska (cash) | ~330–331 days |
| Alaska (select partner awards) | Up to 365 days |
| Southwest | No fixed window; released in ~6–9 month blocks |
| Spirit/Frontier | ~8–11 months, variable |
Does the Booking Window Length Matter for Price?
Not directly. Booking the moment a flight becomes available doesn't guarantee the lowest fare — airlines release seats at a range of prices from the start, with the cheapest fares generally showing up later, closer to the ideal one-to-three-month domestic or two-to-eight-month international window. The booking window mainly matters for availability, not for locking in a specific price.
Learn More About Booking Timing Overall
For a broader explanation of how these booking windows interact with the separate question of when to actually buy for the best price, this guide on advance flight booking covers both angles in more depth.
Bottom Line
American, Delta, United, JetBlue, and Alaska (for cash fares) all cluster around a 330–331 day booking window, while Southwest works on a rolling, batch-released schedule and Spirit and Frontier generally open somewhat later. If you're trying to book as far ahead as possible with a specific airline, checking that carrier's site directly is more reliable than assuming a single standard applies across the board.
