What is what area code is 904?

Area code 904 serves the northeastern corner of the U.S. state of Florida. It primarily covers the city of Jacksonville and its surrounding areas in Duval%20County. Other significant cities within the 904 area code include Fernandina%20Beach, Orange%20Park, and St.%20Augustine. It was one of the original area codes established in 1947. Over the years, due to population growth, the 904 area code has been split to create other area codes in Florida.