Southwest Airlines is running a sale for the next few days, with up to 40% off base fares on select dates and in select markets with promo code 40SALE for travel from 12/3/25 to 3/4/26. Keep in mind that this won’t apply to all flights, and in some cases prices may have been increased to offset the discount.
The Deal
- Southwest Airlines is offering a flash sale on select flights when you book by 10/23/25 and travel from 12/3/25 to 3/4/26 using promo code 40SALE
- Direct link to this deal
Key Terms
- Up to 40 percent off promotion code savings valid for qualifying one-way or round trip Basic and Choice fares booked on Southwest.com® or swabiz.com from October 20 at 12:01 a.m. Pacific Time (“PT”) through October 23, 2025 11:59 p.m. PT (the “Booking Period”)”, and flown between December 3, 2025-March 4, 2026 for continental U.S. travel and continental U.S. travel to/from international, Hawaii, and Puerto Rico (collectively, the “Travel Period”).
- Interisland Hawaii travel is excluded.
- Continental U.S. travel blacked out December 19, December 20, December 26 through December 29, 2025, January 2 through January 4, and February 16, 2026.
- Continental U.S. travel to Hawaii, international, and San Juan, Puerto Rico blacked out December 18, 2025 through January 6 and February 12 through February 15, 2026.
- Continental U.S. travel from Hawaii, international, and San Juan, Puerto Rico blacked out December 18, 2025 through January 6 and February 20 through February 22, 2026.
- Continental U.S. travel valid all days of the week.
- Travel from continental U.S. to Hawaii, and international is valid Sundays, Mondays, Tuesdays, and Wednesdays.
- Travel to continental U.S. from Hawaii, and international is valid Tuesdays, Wednesdays, Thursdays, and Fridays.
- Travel to/from Puerto Rico is valid Mondays, Tuesdays, Wednesdays, and Thursdays.
- Promotion code savings are applied before government taxes and fees.
- Enter promotion code 40SALE in the Promo Code box when booking during the Booking Period.
- Seats, days, and markets are limited.
- If you have entered the promotion code 40SALE in the Promo Code box on Southwest.com or swabiz.com during the Booking Period, then while selecting your flights, savings in the base fare will be visible as a strike-through of the original fare on eligible flights.
- Discount availability may vary by destination, flight, and day of the week, and won’t be available on some flights that operate during very busy travel times and holiday periods. Please note that the Department of Transportation (DOT) requires advertised fares to include all government taxes and fees; however, this promotion applies to the base fare only.
- Discount is valid on new reservations only.
- Discount will apply only for select flights booked within the Booking Period, while supplies last, for travel flown within the Travel Period.
- Changes made to the itinerary after purchase will eliminate qualifications for this promotion and will result in forfeiture of any promotion code savings.
- The discount is only valid with the provided promotion code and is not combinable with other promotion codes or fares.
- All reward travel is subject to taxes, fees, and other government or airport-imposed charges of at least $5.60 per one-way trip.
- See landing page for full details
Quick Thoughts
These flash sales can sometimes be useful if you need to book a flight during the qualifying period. On the other hand, there are numerous blackout dates and availability may be limited on certain routes / day of the week, so the utility will vary considerably from one use case to another.
At least one reader in our Frequent Miler Insiders group posted this morning as they had been tracking a specific route/date for a while via Google flights. They noted that the price of the flight they are tracking (still a couple of months in the future) more than doubled in price for this sale, making the price after 40% off code more still about 30% more than it was previously. I think that type of thing is highly situational, but it’s worth highlighting that experience to know that not every sale is a deal.
Also note in the restrictions that while flights to/from Hawaii are included, interisland Hawaii flights are excluded.
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Got some good fares; booked a couple flights. Agree the base fares appear higher right before sales sometimes, but not all destinations.
I agree with your group member – I checked prices on all of my upcoming flights and most of them were higher than what I’d already locked in. More Southwest BS from their new customer-unfriendly management.
I’m not saying I’ll never travel SWA again. I can see work trips where they’ll be the cheapest option. After all the BS they’ve come up with to become “not Southwest” AND the “let us resell your seat for more $$” ridiculousness, I won’t be spending my money with them.