Southwest Airlines is a major domestic airline that provides primarily short-haul, high-frequency, point-to-point and low-fare services. Founded in 1971, it operates more than 500 Boeing aircrafts in over 64 cities. Southwest was incorporated in Texas and commenced customer service in 1971 with three Boeing 737 aircraft serving three Texas cities - Dallas, Houston and San Antonio. Today, it operates more than 400 Boeing 737 aircraft in 60 cities and has more than 3,000 flights a day. The airline has the lowest operating cost structure in the domestic airline industry and consistently offers the lowest and simplest fares. It also has one of the best overall customer service records. Southwest Airlines currently operates six reservation centers located in Albuquerque, N.M., Chicago, Houston, Oklahoma City, Phoenix and San Antonio. The company trades on the New York Stock Exchange under the symbol LUV. Southwest Airlines is headquartered in Dallas.