Area code 305

Area code 305 is the area code for all of Miami, Florida, Miami-Dade County, and the part of Monroe County in the Florida Keys in the United States. The mainland portion of Monroe County is served by area code 239. The numbering plan area 305 was overlaid by area code 786 in 1998.

Area code 305 was one of the original area codes created in 1947, and originally covered the entire state of Florida. The western part of the peninsula from the Tampa Bay area south, which was served mostly by GTE (now part of Verizon), was separated into area code 813 in 1953. As a result of the increase in the state's population, North Florida from the Panhandle to Jacksonville was assigned area code 904 with a permissive dialing period beginning July 6, 1965, and a mandatory dialing period beginning January 1, 1966.

In 1988, the east coast of Florida from Palm Beach County north through Brevard County, as well as the Orlando metropolitan area was assigned area code 407. In 1995, Broward County was split from 305 and assigned area code 954. Although this was intended to be a long-term solution, within two years the reconfigured area code 305 was already close to exhaustion due to explosive growth in South Florida, as well as the increasing popularity of cell phones and pagers. Available numbers were limited by the fact that Monroe County was split between two area codes, as well as the fact that all of South Florida from the Treasure Coast to the Keys is a single LATA. To solve this problem, area code 786 was installed as an overlay in 1998. The overlay originally only covered Miami-Dade County; the Keys were added in 2008.

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