Flying has never been cheaper on paper – and rarely more expensive in practice. The base fare you see when you search for a flight is often just the beginning of what you’ll actually pay. Online travel agencies and search engines push airlines to keep their base ticket prices low so they appear higher in search results, and airlines then recoup those costs through fees for extras like baggage, priority boarding, and window seats. The numbers tell the whole story: total global ancillary revenue surpassed $148 billion in 2024, a sharp increase from the 2019 record of $109.5 billion. Six US carriers stand out as the most aggressive players in this game – each with its own approach to charging you for things you probably assumed were included.
1. Frontier Airlines – The King of Ancillary Charges
Frontier claimed the top spot at 62 percent ancillary revenue, breaking the 60 percent threshold in 2024 for the first time. That means more than half of everything the airline earns comes not from selling you a ticket, but from selling you everything that goes with it. Frontier has positioned itself as an à la carte airline, so you’ll pay an upcharge for everything, including bags. Although you might find some incredibly low fares, Frontier baggage fees will significantly increase your trip’s cost, and the overall price may not always be affordable.
Frontier has a strict 40-pound weight limit on checked bags, while many other airlines allow bags up to 50 pounds – a meaningful difference in how much you can pack. Things get even more aggressive at the gate. Frontier charges almost double at the gate for bags you could have added online. A Senate investigation found that Frontier paid incentives to gate agents “to catch passengers allegedly not following airline bag policies, often forcing those passengers to pay a bag fee or miss their flight,” with agents earning as much as $10 per bag caught.
2. Spirit Airlines – Fees Built Into the DNA
Spirit followed Frontier at 58.7 percent ancillary revenue in 2024, making it the second-most dependent airline on fees rather than fares in the entire country. Spirit is a low-cost carrier, which means that the price you pay for the flight includes only the ticket itself. You will need to pay for everything you’d like to add, such as bags, printing your boarding pass at the airport, selecting your seat, meals on the flight, early boarding, and more. That’s not an exaggeration – even water costs extra on board.
Spirit has again tweaked its pricing structure with a notable hike in checked baggage fees. Passengers opting to pay for their checked bags at the airport check-in desk will now face a charge of $89, a considerable cost jump. On the political radar, three US senators demanded that Frontier and Spirit disclose whether they are manipulating seat fees by using customers’ personal information to charge different fees to passengers on the same flight, with the carriers apparently asking for personal information before revealing seat fees. That’s a level of fee engineering that goes well beyond a simple surcharge.
3. JetBlue Airways – Surge Pricing Comes to Baggage
United Airlines and JetBlue Airways charge more for bags than the other major full-service carriers. JetBlue can actually be worse than standard data shows, since they introduced surge pricing for baggage in 2024 – meaning bags cost more on high-demand days. That’s a concept borrowed from ride-sharing apps and applied directly to your suitcase. JetBlue was by far the most expensive carrier for seat selection fees among the major full-service airlines analyzed in 2026.
JetBlue introduced surge pricing for baggage, meaning bags cost more on high-demand days. Even worse, if you wait to check your bags until you get to the airport, you’ll pay $10 more per bag – $50 for the first bag and $70 for the second. Seat selection fees on JetBlue range from $25 to $100 per flight segment, with extra legroom seats costing up to $319. For frequent travelers, those numbers stack up fast across a full year of flying.
4. United Airlines – Basic Economy and Big Seat Fees
A Senate investigation found that in 2023 alone, American, Delta, United, Frontier, and Spirit collected more than $3 billion in seat fees only – not airfare, just fees for booking a specific seat in advance or selecting a slightly better seat. United was among the leaders in that figure. According to the Senate Permanent Subcommittee on Investigations, United Airlines charged as much as $319 for an extra legroom seat in 2023, the highest of all five airlines examined in the probe.
If you prefer to book by phone, expect to pay up to $25 per ticket with United, a fee that competitors like Delta have eliminated. United has also been a major driver of the basic economy model. United is one of the main promoters of the basic economy fare, which may be driving higher checked baggage fees from passengers on these fares who are not allowed to bring a carry-on bag onto the aircraft. That restriction alone forces millions of travelers into paying for bags they’d otherwise carry on for free.
5. American Airlines – Raising the Bar on Checked Bag Costs
American Airlines has been systematically raising the cost of checked luggage. Bag fees were updated effective for tickets issued on or after February 18, 2026, with the first checked bag fee now at $40 ($35 if paid online) and the second checked bag at $50 ($45 if paid online) for domestic travel. That’s a meaningful increase over prior rates, and it applies per person, each way. American charges up to $160 for extra legroom seats on international routes.
Overall, five US carriers collected $12.4 billion in seat fees between 2018 and 2023, in addition to baggage and other charges, according to a Senate subcommittee report. American was a central figure in that figure. Senator Richard Blumenthal noted that seat fees represented an increase of 50 percent from 2018, just six years ago. For a carrier that flies nearly 200 million passengers per year, those compounding fees translate into billions extracted from travelers who likely had no idea what they were agreeing to when they hit “book.”
6. Southwest Airlines – The Last “Free” Holdout, Now Charging Too
Southwest Airlines was long the one major US carrier passengers could count on for honest pricing. That era is officially over. In May 2025, Southwest abandoned its 50-year “bags fly free” policy. Starting in May 2025, Southwest discontinued its 2 free checked bag policy. The airline now charges $35 for the first checked bag, $45 for the second, and $150 for subsequent bags. Passengers who built years of brand loyalty around that one policy got nothing in return for it disappearing.
Southwest launched assigned seating on January 27, 2026, expecting to make $1.5 billion annually from seat selection fees alone. Southwest used to dominate the value-for-money category, but its new policy of charging for bags and seat selection puts it toward the bottom of the pack. The transformation of Southwest from fee-free champion to fee-charging airline is perhaps the clearest signal yet of where the entire US industry has landed – a world where hidden fees, baggage charges, seat selection, and booking costs now account for over 20 percent of airline revenue industry-wide.
