Out of the top 20 largest call centers in the United States, three are based in Arizona. The largest call center in the United States, American Express' call center, is located in Arizona.
American Express' call center is based in Phoenix, Arizona, and employs an estimated 5,200 employees, as of 2015. Bank of America's call center is the 10th largest in the U.S. Approximately 2,946 employees work at the Phoenix facility. JPMorgan Chase operates a call center in Phoenix as well, with an estimated staff of 2,825. Call center facilities perform many functions, such as customer service, sales, claims processing and technical support.