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Most Unreliable Airlines Serving the U.S. and U.K. Revealed

The seven most unreliable airlines in the U.S. were all domestic carriers, with American Airlines ranked as the worst

by Fergus Cole

January 26, 2023

Frustrated at the terminal / Photo: F8 studio/Shutterstock

If you’ve ever had to make a complaint to an airline and felt like you were getting nowhere, you’re not alone. The most unreliable airlines in the U.S. and U.K. have been unveiled in a new ranking, with domestic carriers dominating the list.

Analysis from price comparison website ComparetheMarket looked at a number of metrics related to airlines that serve destinations in the U.S. and the U.K. The biggest factor was the total number of complaints received, with their reasoning being that the more complaints an airline had, the less reliable it is perceived as being. The ranking also looked at how many of those complaints were remedied and what caused them in the first place, such as lost luggage or flight cancelations.

In the U.S., ComparetheMarket named American Airlines the most unreliable airline overall, with a total of 6,491 complaints recorded over the last 12 months. In fact, the seven worst-performing airlines were all U.S.-based carriers: American, United, Spirit, JetBlue, Frontier, Delta, and Southwest Airlines.

American Airlines performed the worst in all but two categories. The exceptions were for lost and delayed baggage, for which United Airlines had the most instances; and discrimination, as Lufthansa received 41 civil rights complaints.

It should be noted that although this ranking of the most unreliable airlines is dominated by U.S. carriers, this data is skewed by the fact that U.S. travelers are much more likely to use these airlines, and thus they are more likely to receive complaints.

Still, there were some notable winners when it came to international airlines. The most reliable airline, according to U.S. travelers, was Aerolineas Argentina, which received just one complaint in the last year regarding customer service and only four cases of refund issues. This was closely followed by Air New Zealand, Canada’s Air Transat, Azerbaijan Airlines, and low-cost Brazilian carrier Gol Airlines.

Here is the list of the 20 most unreliable airlines:

Ranking Airline Number of complaints
1 American Airlines 6,491
2 United Airlines 5,135
3 Spirit Airlines 3,206
4 JetBlue Airways 2,979
5 Frontier Airlines 2,871
6 Delta Air Lines 2,851
7 Southwest Airlines 2,174
8 Lufthansa 1,796
9 Air India 1,661
10 Air Canada 1,292
11 TAP Air 1,247
12 Other foreign airlines 1,246
13 Allegiant Air 1,139
14 Air France 1,110
15 Turkish Airlines 1,009
16 British Airways 897
17 Qatar Airways 876
18 Aeromexico 754
19 Alaska Airlines 674
20 Avianca 673

A separate list was compiled based on data from U.K. travelers, with low-cost carrier easyJet being named the most unreliable airline across the pond, with a massive 20,906 complaints received last year. This was followed by TUI and Ryanair, with U.K. flag carrier British Airways coming in fourth. The only U.S.-based airline to rank in the 20 most unreliable to serve the U.K. was Delta Air Lines, coming in at number 19 with 178 complaints.