What is what area code is 305?

Area code 305 serves [South Florida], primarily [Miami-Dade County], including the city of [Miami]. It was one of the original area codes established in 1947. Due to population growth and increased demand for phone numbers, the region is now also served by overlay area codes like 786. So, while 305 is still active, new numbers are often assigned in the 786 area code. It essentially covers the southeastern tip of Florida.