Area code 412
Area code 412 is an area code for Pennsylvania. It was one of the initial area codes created in 1947. It initially covered the entire southwestern corner of the state but after it was split by 724, it is now a doughnut area code with 724 surrounding it. It covers cities such as Pittsburgh, Carnegie, Robinson Township, Franklin Park, and Ross Township. It was overlaid by 878 in 2001, which also overlaid 724.