Area code 612

Area code 612 is part of the North American Numbering Plan (NANP) of the public switched telephone network for the city of Minneapolis, Minnesota and a few surrounding areas such as Fort Snelling, St. Anthony and Richfield. By geographical area, it is the smallest area code in the state of Minnesota. However, like every single metropolitan area code in the United States, the region used to be much larger, accounting for the entire Twin Cities region and a wide area surrounding it.

At the outset, Minnesota received two area codes, 612 and 218. A 1947 map of the NANP showed the region defined as roughly the southeastern third of Minnesota. The rest of the state was 218, which formed an r-shaped region around the 612 area code. The separating line extended westward from Duluth to the center of the state, then down through the center.

In 1954, the state was divided into three area codes. Part of the southern portion of the previous 612 territory, including Rochester and Mankato, was combined with the southwestern portion of 218 to form the new area code 507. The 612 area code was rotated out to reach the western edge of the state, stretching from border to border from Wisconsin through the Twin Cities to South Dakota. The 218 region was reshaped to be more square, absorbing much of the old 612's northeastern portion, and now covered roughly the northern half of the state. This configuration remained in place for 42 years.

In 1996, almost all of the old 612 territory outside of the Twin Cities became area code 320. The 612 region was roughly split in half two years later in 1998, mostly following the Mississippi River. The area west of the Mississippi, including Minneapolis, retained the old code, while most of the area east of the Mississippi—including St. Paul—became the new area code 651.

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