These U.S. airlines have the most oversold flights

When you’re about to head off on a vacation or returning home after a long trip, the possibility of being told you cannot board your flight can ruin your plans. Yes, denied boarding is a thing. When airlines oversell a flight, passengers can be selected to involuntarily move to the next flight. Airlines oversell for a reason, but for some airlines, the practice can be excessive. A study by QR Code Generator highlights the airlines with the highest number of oversold flights and the highest denied boarding rates.

Overbooking is a practice airlines use to maximize. They sell more tickets than there are seats, expecting that a few travelers will be no-shows. It's a smart move for keeping planes full—which is more fuel-efficient and environmentally friendly—and boosting revenue, but when everyone actually shows up, chaos kicks in. Most people want to get where they’re going and getting left at the gate intentionally is even more exasperating than a flight delay. Most airlines offer incentives like travel vouchers and hotel stays, but if no one accepts the offer, staff must choose which passengers to get bumped: involuntary denied boarding.

According to the study, which analyzed data from the Air Travel Consumer Report (2023-2024) conducted by the US Department of Transportation, Endeavor Air (a regional airline operating on behalf of Delta Airlines) has the highest rate of denied boarding due to oversold flights at 13.05 denied boarding per 10,000 passengers. Since January 2023, 19,846 passengers have been denied boarding. All were voluntary, but this indicates significant issues with their overbooking practices.

The second worst offender is SkyWest Airlines with a rate of 7.99 denied boarding per 10,000 passengers—a significantly lower rate than Endeavor, but still high. Plus, 889 passengers were involuntarily denied boarding since 2023. At number three is Frontier, with a rate of 6.47 and 11,238 involuntarily denied boarding. Rounding out the top five are Spirit and Delta.

The U.S. airlines with the most oversold flights in 2023 and 2024

(Passengers denied per 10,000)

1. Endeavor Air 13.05
2. SkyWest Airlines 7.99
3. Frontier Airlines 6.47
4. Spirit Airlines 6.41
5. Delta Airlines 6.32
6. PSA Airlines 5.34
7. Republic Airways 3.64
8. Envoy Air 3.61
9. Alaska Airlines 2.83
10. Southwest Airlines 2.42
11. American Airlines 2.24
12. JetBlue Airways 2.04
13. United Airlines 1.86
14. Hawaiian Airlines 0.83
15. Allegiant Air 0.66