Flying is stressful enough without having difficulty dealing with customer service, but Southwest has come out ahead of other airlines as the easiest company for travelers to deal with, according to an index released on Wednesday, according to USA Today. The index ranks companies based on how simple they are to deal with.

Southwest came is as the highest-ranked travel company. The company was ranked number nine out of 125 businesses with well-known brands in the U.S., according to the survey that was conducted by Siegel+Gale, a strategic branding firm based in New York. Southwest increased its rank by six spots from its ranking last year.

Customers feel that the airline is easy to deal with, and the perception that Southwest offers fair prices that don't dramatically spike because of extra fees being added on, Brian Rafferty, the director of global research for Siegel+Gale, said.

"Transparency is one thing Southwest is doing well and people also...feel they have very good service and they care about the customer," Rafferty said.

The annual survey includes a global simplicity index and separate rankings for six regions, including the United States, the United Kingdom and the Middle East.

JetBlue ranked at number 44, increasing its rank by 24 spots from last year. The larger carriers, however, ranked near the bottom for U.S. companies. Among those carriers, US Airways ranked at 103, American was ranked at 105, United was ranked at 115 and Delta was ranked at 116.

Airlines are "one of the industries where there's the biggest gap between the leaders and the laggards," Rafftery said.

The larger carriers ranked lower because travelers gave negative reviews for extra fees that are not made clear to customers up front, according to Kathleen Kindle, a strategy director for brand development at Siegel+Gale.

"People are super price-conscious and they don't want to know there's an extra $150 tacked on if they change their flight," Kindle said.

The top ranking company overall was Amazon.