Area codes 301 and 240 are telephone area codes in the North American Numbering Plan (NANP) for the western part of the U.S. state of Maryland. The numbering plan area (NPA) comprises Maryland's portion of the Greater Washington, D.C. metro area, portions of southern Maryland, along with rural western Maryland. This includes the communities of Cumberland, Frederick, Hagerstown, Gaithersburg, Potomac, Germantown, Bethesda, Rockville, Landover, Silver Spring, and Waldorf. History Area 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. The area code served the entire state of Maryland. 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. 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. The entire metro area was also reachable via long-distance services by dialing area code 202, for which purpose AT&T had established cross-referenced operator routing codes for all affected central offices. For example, if 202-574 numbers were in use in the District or 703-574 numbers were in use in Northern Virginia, the corresponding 301-574 numbering block could only be assigned in areas considered a safe distance away from the capital, such as the Eastern Shore of Maryland. Ten-digit dialing By the end of the 1980s, the Washington metropolitan area was running out of unassigned prefixes for new central offices. The only available prefixes could not be assigned without breaking seven-digit dialing in the region. With this in mind, the three local operating companies of The Chesapeake and Potomac Telephone Company (C&P Telephone, later part of Bell Atlantic and now Verizon) decided to mitigate this situation by ending the code protection scheme as of October 1, 1990, with the result that all local metro area calls between Maryland, the District of Columbia, and Virginia required dialing the area code for calls to another NPA. Area code 202 was no longer useable for suburban points. Local calls within Maryland did not require the area code. Permissive dialing using the old dialing procedures continued from April 1 through October 1