Area code 320 is a telephonearea code in theNorth American Numbering Plan for most of the central part of theU.S. state ofMinnesota. The numbering plan area (NPA) excludes theTwin Cities metro region. The area code was created in 1996 in a split ofarea code 612.
In 1995, US West advised theNorth American Numbering Plan Administration (NANPA) that substantial demand for telephone numbers in Minneapolis/St. Paul required dividing numbering plan area 612 with the introduction of a new area code, 320, outside of the metro area.[1] The split became effective on March 17, 1996, with a period of permissive dialing of 612 or 320 ending on September 15 for calls to a 320 destination. The Twin Cities retained the existing area code. Some exchanges, in Red Wing, Wabasha, Goodhue, Lake City, and White Rock in the south-eastern corner of the area were migrated toarea code 507 instead of receiving a new area code. This required changing central office predix and station number changes for customers in the 345, 380, and 388 exchange areas, to mitigate numbering conflicts in NPA 507.
320 was the fourth Minnesota area code, and the first new one in the state in 42 years.
In 1998, numbering plan area 612 was reduced to onlyMinneapolis and a few inner suburbs, whenarea code 651 was created.[2] The 651 area borders Wisconsin, while area codes763 and952 were split from 612 in 2000.Area code 218 borders 320 to the north, andarea code 507 covers southern Minnesota. 320 now borders every Minnesota area code except 612, the numbering plan area from which it first was created.
| North:218 | ||
| West:605,701 | 320 | East:534/715,763,952 |
| South:507/924,651 | ||
| North Dakota area codes:701 | ||
| South Dakota area codes:605 | ||
| Wisconsin area codes:262,414,608/353,715/534,920/274 | ||