

From 1947 to 1990, it was possible to dial any other telephone number in the metro area as a local call with only seven digits, not using an area code, irrespective of the home area code. Much of the Washington metropolitan area is part of a local calling area which is centered on the District's area code 202, and also extends into the suburban area in southern Maryland with 301 and Northern Virginia with area code 703. The area code served the entire state of Maryland.

This includes the communities of Cumberland, Frederick, Hagerstown, Gaithersburg, Potomac, Germantown, Bethesda, Rockville, Landover, Silver Spring, and Waldorf.Īrea code 301 was one of the original North American area codes when the American Telephone and Telegraph Company (AT&T) established a new, nationwide telephone numbering plan in 1947.

metro area, portions of southern Maryland, along with rural western Maryland. The numbering plan area (NPA) comprises Maryland's portion of the Greater Washington, D.C. This map is clickable click on any neighboring area code to go to the page for that code.Īrea codes 301 and 240 are telephone area codes in the North American Numbering Plan (NANP) for the western part of the U.S. The red area indicates area codes 240 and 301. Maryland consists of the red and blue areas.
