Area Code 620 covers telephone exchanges in most of southern Kansas. It was created as the result of a split from 316 on February 3, 2001. The area code stretches from the Colorado border to the east, to the Missouri border. It completely surrounds 316, which now only serves Wichita and its inner suburbs, making it one of the six pairs of "doughnut area codes" in the numbering plan. Permissive dialing of 316 across southern Kansas continued until November 3, 2001.
620 was created due to the growing proliferation of cell phones in the Wichita area. With the great majority of the old 316's landlines and cell phones located in the Wichita area, 620 is one of the most thinly populated area codes in the nation. Under the most recent projections, southern Kansas will not need another area code until the fourth quarter of 2037. 
Major cities in area code 620
Boundaries of area code 620
The boundary between area codes 620 and 785 runs from west to east roughly following a path along K-4 and K-96. The code boundary dips along I-135 in McPherson County and continues east to just north of Emporia in Lyon County along the Kansas Turnpike, where the boundaries of area codes 620, 785 and 913 meet. Area code 620 shares its northern boundary with area code 913's southern boundary, ending south of the Kansas City metropolitan area.
- NANPA area code map of Kansas
- Area Code History[permanent dead link]
- 1947 Area Code Assignment Plan
- List of exchanges from AreaCodeDownload.com, 620 Area Code
|Kansas area codes: 316, 620, 785, 913|
|North: 785, 913|
|West: 719||area code 620 completely surrounds 316||East: 417|
|South: 580, 539/918|
|Colorado area codes: 303/720, 719, 970|
|Missouri area codes: 314, 417, 573, 636, 660, 816|
|Oklahoma area codes: 405, 539/918, 580|