Area code 202
Area code 202 is the North American telephone area code for Washington, D.C.. The area code was one of the original area codes established in October 1947 by AT&T in the North American Numbering Plan (NANP).
After the State of New Jersey with area code 201, the District of Columbia was the second Numbering Plan Area (NPA). NPAs that covered an entire administrative region received a code in which the second digit was '0'.
As of 2012, no plans exist to overlay the 202 area code, as NANPA estimates the current supply of numbers is sufficient at least to the year 2019. Washington is thus one of the largest cities where seven-digit dialing is still possible. However, calls are connected if the area code is dialed. There is no provision for long-distance calls within the area code.
From the 1950s to 1990, area code 202 was an unpublished alternate area code for the nearby suburbs in Maryland and Virginia, which were officially in area codes 301 and 703, respectively. This arrangement permitted seven-digit dialing of local calls throughout the metropolitan area. One side effect was that a central office prefix could only be duplicated in jurisdictions a safe distance from the metropolitan area, such as the Eastern Shore of Maryland or southwestern Virginia. However, on October 1, 1990, this arrangement was terminated because of pending number exhaustion throughout the area. This did not free up enough numbers to meet demand on either side of the Potomac River, forcing the split of area code 410 from 301 in 1991 and the split of area code 540 from 703 in 1995. The region's continued growth in the 1990s ultimately resulted in the suburban area codes being overlaid, with 301 being overlaid with 240 in 1997 and 703 being overlaid with 571 in 2000.
Years after the introduction of mobile number portability, a large number of cell phone customers on the Virginia and Maryland sides of the metro have 202 numbers.