Area code 816 is the area code for Kansas City, St. Joseph, and all or part of 15 surrounding counties in northwestern Missouri. This area code originally covered most of the northern and western two-thirds of the state, including its borders with Arkansas, Illinois, Iowa, Kansas, Nebraska, and Oklahoma, but has been reduced so that it only serves a ribbon bordering Kansas. Within Missouri, 816 borders only area code 660, the latter being a relief code when 816 was nearing exhaustion.
When the North American Numbering Plan was created in 1947, Missouri was divided into two numbering plan areas. Area code 816 served all points west of Jefferson City, while area code 314 served the east from Jefferson City to St. Louis. However, in 1951 a third NPA, area code 417, was created for the southwest, including the cities of Branson, Joplin, and Springfield. By late 1996 the proliferation of cell phones, especially in the Kansas City area, and other market reforms related to deregulation by the Telecommunications Act of 1996, required that northwestern Missouri received an additional area code. The supply of telephone numbers was further limited because the Kansas City LATA extends some distance into eastern Kansas, meaning that several numbers in area code 913, the area code for most of the Kansas side of the Kansas City area, were not available for use. In early 1997, the Missouri Public Service Commission, which oversees telecommunications in the state, held hearings regarding a possible split of the area code. The original recommendation of the Missouri PSC was to assign a new area code, 660, to the eastern and northwestern portions of the 816 territory, to cause the least disruption. Generally, St. Joseph and metropolitan Kansas City were left in 816. Two notable exceptions were Lexington and Warrensburg, which were included in 660 even though they are generally considered as part of the Kansas City area. On June 4, 1997, the Missouri PSC announced that 660 would begin its split on October 12, 1997. On that date, a permissive dialing period began during which long-distance calls to the 660 territory could be completed using either 816 or 660. On April 19, 1998, 660 became mandatory for all calls in the affected area. In 2000, the Missouri PSC announced plans to add 975 as an overlay to the 816 area code; however, with the subsequent implementation of number pooling, the commission determined there was no immediate need for additional phone numbers and postponed the May 5, 2002 implementation date indefinitely. Despite Kansas City's continued growth and the fact that the metropolitan area is a single LATA, the Kansas City area will not need another area code until 2026. Kansas City is one of the fewmajor cities where seven-digit dialing is still possible, along with nearby major cities St. Louis, Springfield and Wichita.
