Southwest debuted the international reservation system on January 27, 2014, when its first international flights went on sale. This agreement gave the airline the capability to begin flying to destinations outside of the United States. Southwest's first approach to international service came on April 19, 2012, when it signed a contract with the Amadeus IT Group to launch an international reservation system. Southwest began planning international service when it acquired AirTran Airways, which already served international destinations. airlines, Southwest does not fly outside North America, and it does not fly to Canada due to its payment system not being set up for Canadian dollars (however, Southwest does market Bellingham to cater to Canadian passengers in the Vancouver and Southern BC area as a low cost alternative to Vancouver International Airport).

Until 2006, Southwest did not fly into Denver, which is now its most popular destination. In most cities where Southwest uses both a primary and secondary airport, the secondary airport is used more than the primary for flights (such as Oakland instead of San Francisco), with some exceptions such as the Los Angeles metro area, where Los Angeles International is a Southwest base and secondary airports (such as Burbank, Long Beach, Santa Ana and Ontario) have limited Southwest operations despite having a higher market share at the smaller airports. In recent years however, the airline has been expanding into primary airports as well. Īs part of its effort to control costs, Southwest historically used secondary airports in cities where the primary airports have high costs, such as Chicago, Dallas/Fort Worth, Houston and Miami. However, at Southwest's focus cities, the percentage of connecting passengers can reach 30 percent. An average of 80 percent of Southwest passengers are local passengers-only 20 percent are connecting passengers, a lower percentage than on most major airlines, where many passengers connect in hub cities. It has large operations in certain airports. Southwest does not use the ' hub and spoke' system of other major airlines, preferring instead the ' point-to-point' system with focus cities. Destinations Southwest B737 on final approach to San Jose International Airport. The airline has 15 focus cities and operates over 4,000 flights each day. As of November 2023, Southwest Airlines has scheduled flights to over 100 destinations in 42 states, Puerto Rico, Mexico, Central America and the Caribbean, the newest being Syracuse, New York on November 14, 2021.

Southwest airline flight map