When the
American Telephone and Telegraph Company (AT&T) designed the initial version of the first nationwide
telephone numbering plan for
Operator Toll Dialing, the predecessor of the North American Numbering Plan (NANP), in 1947, the entire state of Florida was designated a single
numbering plan area (NPA), and assigned the
area code 305. In 1953, the western part of the peninsula from the
Tampa Bay area southward received
area code 813, and in 1965,
North Florida from the
panhandle to
Jacksonville was assigned
area code 904 to mitigate the demand for telephone service for the state's growth in population. For thirty years, North Florida remained a single NPA until 1995, when the southern part of the region was split off with
area code 352. Continued demand put new pressure on the numbering resources, and within a year, further relief action was in the planning stage. The result was that the far western part of the panhandle (south of the Alabama state line) became a new numbering plan area with area code 850.
Permissive dialing in the numbering plan area began June 23, 1997, and mandatory dialing commenced on March 23, 1998. moving to 850 and Jacksonville and Daytona Beach retaining 904.
Area code 234 has since been placed into service in Ohio as an
overlay with area code 330.
Relief planning for an overlay Area code 850 exhausted its available supply of central office codes in May 2021. Based on previous exhaust forecasts, the Florida Public Service Commission began relief planning to provide additional numbering capacity for NPA 850. In an initial planning meeting on May 16, 2019, industry members recommended an all-services overlay as the preferred relief method. NANPA subsequently filed a request with the Florida Public Service Commission to approve a new area code overlaying 850. The Florida Public Service Commission approved the industry's all-services overlay recommendation on November 5, 2019. The new area code, 448, was officially assigned to overlay 850.
Ten-digit dialing became mandatory on May 22, 2021. The in-service date, when first central office code assignment can become effective, is June 22, 2021. The first central office code assignment within the 448 area code occurred on May 14, 2021. ==Service area==