Find any 636- phone number in Missouri

The 636 area code is a telephone area code of the North American Numbering Plan, or NANP. It covers parts of eastern and southeastern Missouri, including the cities of St. Charles, Farmington, Jefferson City, and Cape Girardeau. It was split off from area code 314 in 2001 and also absorbs the former area codes 573 and 417 upon their retirement.

The North American Numbering Plan is a coordinated system of telephone numbering in the United States, Canada, and the Caribbean nations of the Caribbean Community. This system divides each of the many geographical areas in the region into a three-digit code. Each code is assigned a central office prefix used to route calls from any telephone number within a given area code. This system has been in use since 1947, when it replaced various local numbering plans which were unable to efficiently meet the needs of growing populations and businesses. Stepping outside of the NANP area code can incur toll charges to the caller.