image:Area code 301.png, 300px, alt=area codes 240 and 301 possibly 308. These numbers are related to the main zip codes of Maryland., Maryland consists of the red and blue areas. The red area indicates area codes 240 and 301. This map is clickable; click on any neighboring area code to go to the page for that code. poly 336 37 323 30 310 13 305 -2 337 2

Area codes 215, 267, and 445 Area codes 215, 267, and 445 are the North American telephone area codes for the City of Philadelphia as well as adjacent portions of Bucks and Montgomery counties in the Commonwealth of Pennsylvania. The original area code is 215, which was e ...

poly 339 121 325 118 296 86 296 73 307 56 319 51 328 48 327 42 337 34

Area code 856 Area code 856 is a telephone area code in the North American Numbering Plan (NANP) for the southwestern part of the U.S. state of New Jersey. The numbering plan area (NPA) includes the Camden, Cherry Hill, and Vineland areas, as well as a small ...

poly 248 1 257 11 265 35 253 43 264 50 258 64 278 67 286 56 294 54 305 58 328 47 324 41 335 35 322 30 304 -2

Area code 484 __NOTOC__ Year 484 (Roman numerals, CDLXXXIV) was a leap year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Venantius and Theodoricus (or, less freq ...

poly 85 65 88 53 101 43 109 48 111 33 100 12 94 4 100 -1 245 -1 258 12 266 35 250 43 263 50 256 66

Area code 717 Area codes 717 and 223 are telephone area codes in the North American Numbering Plan (NANP) for South Central Pennsylvania and the Susquehanna Valley. The numbering plan area (NPA) includes the Harrisburg, Lancaster and York metropolitan are ...

poly 36 1 43 9 38 19 37 29 17 44 14 67 84 66 87 53 101 44 106 48 111 35 96 5 96 -1 Area code 814 poly 2 2 0 65 16 68 18 43 39 30 40 17 45 10 35 2

Area code 724 Area code 724 is a Commonwealth of Pennsylvania telephone area code in western and southwestern Pennsylvania, including most of the suburbs of Pittsburgh. It was split from area code 412 on February 1, 1998. Originally, Bell Atlantic wanted to i ...

poly 181 143 184 134 195 144 186 156 184 147 182 142

Area code 202 Image:Area code 202.svg, 350px, The red area is the District of Columbia, served by area code 202. poly 0 50 49 54 103 84 111 88 101 107 118 130 143 139 179 140 211 188 238 203 260 240 259 248 248 250 255 262 253 357 1 357 Area codes 571 and 7 ...

poly 168 182 169 171 177 170 176 165 184 162 184 152 179 139 168 135 171 131 148 123 141 129 148 166

Area code 571 __NOTOC__ Year 571 ( DLXXI) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. The denomination 571 for this year has been used since the early medieval period, when the Anno Domini calendar er ...

poly 327 230 290 235 282 236 283 246 317 243

Area codes 757 and 948 Image:Area code 757.png, The area colored red indicates the southeast corner of Virginia served by area code 757 poly 60 2 11 58 12 78 32 106 40 109 45 105 68 123 73 119 95 128 97 122 126 124 132 110 127 103 139 79 154 79 176 42 197 41 217 1 25 ...

poly 336 153 335 186 288 188 277 69 286 56 294 55 303 57 298 76 299 88 316 129

Area code 302 Area code 302 is a telephone area code in the North American Numbering Plan (NANP) for the U.S. state of Delaware. It is Delaware's only area code, and was assigned in 1947 as one of the original North American area codes. Despite the rapid gr ...

poly 337 190 327 226 278 242 235 193 219 187 214 168 211 157 211 135 205 121 201 116 198 109 200 105 173 94 175 86 167 66 275 67 288 188 Area codes 410, 443, and 667 poly 0 68 -1 184 16 191 22 186 38 151 51 159 85 118 88 103 87 90 125 121 133 106 135 97 129 92 128 87 122 84 126 81 126 75 116 77 104 68 98 69 93 75 86 73 81 77 79 84 69 84 61 81 59 76 59 73 54 74 43 93 37 88 32 87 31 94 4 117 5 67 Area code 304/681 poly 247 250 249 239 221 220 214 212 200 213 189 199 184 211 169 211 142 226 121 223 106 243 113 248 Area code 804 poly 48 250 34 235 60 212 84 208 79 192 77 189 93 172 106 185 122 223 106 243 107 247 Area code 434 # poly 1 248 1 184 15 193 22 187 39 151 49 159 58 142 62 147 67 137 69 140 84 118 88 102 87 90 126 123 135 105 138 107 144 105 149 110 153 112 154 114 147 120 149 123 142 131 148 168 167 182 164 189 169 199 179 199 185 193 189 198 183 211 168 211 143 227 121 224 106 184 94 172 78 189 85 208 61 211 34 237 44 247 Area code 540 # desc bottom-left Area codes 301 and 240 are

telephone A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...

area code A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, rea ...

s in the

North American Numbering Plan The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international callin ...

(NANP) for the western part of the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

. The numbering plan area (NPA) comprises Maryland's portion of the Greater

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

metro area, portions of

southern Maryland Southern Maryland is a geographical, cultural and historic region in Maryland composed of the state's southernmost counties on the Western Shore of the Chesapeake Bay. According to the state of Maryland, the region includes all of Calvert, Cha ...

, along with rural western Maryland. This includes the communities of

Cumberland Cumberland ( ) is a historic county in the far North West England. It covers part of the Lake District as well as the north Pennines and Solway Firth coast. Cumberland had an administrative function from the 12th century until 1974. From 19 ...

Frederick Frederick may refer to: People * Frederick (given name), the name Nobility Anhalt-Harzgerode *Frederick, Prince of Anhalt-Harzgerode (1613–1670) Austria * Frederick I, Duke of Austria (Babenberg), Duke of Austria from 1195 to 1198 * Frederick ...

, Hagerstown,

Gaithersburg Gaithersburg ( ), officially the City of Gaithersburg, is a city in Montgomery County, Maryland, United States. At the time of the 2020 U.S. Census, Gaithersburg had a population of 69,657, making it the ninth-largest location in the state. Ga ...

, Potomac,

Germantown Germantown or German Town may refer to: Places Australia * Germantown, Queensland, a locality in the Cassowary Coast Region United States * Germantown, California, the former name of Artois, a census-designated place in Glenn County * Ge ...

, Bethesda, Rockville, Landover, Silver Spring, and Waldorf.

History

Establishment

Area code 301 was one of the

original area codes The original North American area codes were established by the American Telephone & Telegraph Company (AT&T) in 1947, following the demonstration of regional Operator Toll Dialing during the World War II period. The program had the goal of speedin ...

when the NANP was established in 1947. It served the entire state of Maryland. Much of the

Washington metropolitan area The Washington metropolitan area, also commonly referred to as the National Capital Region, is the metropolitan area centered on Washington, D.C. The metropolitan area includes all of Washington, D.C. and parts of the states of Maryland, Virgi ...

is part of a local calling area which is centered on the District's

area code 202 Image:Area code 202.svg, 350px, The red area is the District of Columbia, served by area code 202. poly 0 50 49 54 103 84 111 88 101 107 118 130 143 139 179 140 211 188 238 203 260 240 259 248 248 250 255 262 253 357 1 357 Area codes 571 and 7 ...

, and also extends into the suburban area in southern Maryland with 301 and

Northern Virginia Northern Virginia, locally referred to as NOVA or NoVA, comprises several counties and independent cities in the Commonwealth of Virginia in the United States. It is a widespread region radiating westward and southward from Washington, D.C. Wit ...

with

area code 703 __NOTOC__ Year 703 ( DCCIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 703 for this year has been used since the early medieval period, when the Anno Domini calendar era ...

. 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 The Eastern Shore of Maryland is a part of the U.S. state of Maryland that lies mostly on the east side of the Chesapeake Bay. Nine counties are normally included in the region. The Eastern Shore is part of the larger Delmarva Peninsula that ...

Ten-digit dialing

By the end of the 1980s, the

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 Verizon Communications Inc., commonly known as Verizon, is an American multinational telecommunications conglomerate and a corporate component of the Dow Jones Industrial Average. The company is headquartered at 1095 Avenue of the Americas ...

) 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.Jordan, Mary; Quimpo, Margie G. (September 23, 1990). "Territorial Telephones; On Oct. 1, Local Calls Will Get Complicated". ''The Washington Post''. p. 1. Permissive dialing using the old dialing procedures continued from April 1 through October 1 1990.

Split

Despite the overall growth of the Baltimore–Washington metropolitan area, 301 remained the exclusive area code for Maryland for 44 years, making Maryland one of the largest states with a single area code. By the end of the 1980s, however, it became apparent that breaking seven-digit dialing in the Washington area would not free up enough numbers north of the

Potomac River The Potomac River () drains the Mid-Atlantic United States, flowing from the Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map. Retrieved Augus ...

to stave off the immediate need for a new area code.

Baltimore Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...

and the Eastern Shore were split off as

area code 410 __NOTOC__ Year 410 (CDX) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year after the Consulship of Honorius and Theodosius (or, less frequently, year 1163 ...

on November 1, 1991. The split largely followed metropolitan area lines. There were a few exceptions, such as in Howard County, which is often recognized as part of the Baltimore metropolitan area, a small portion of the county remained in area 301, while the rest of the county was reassigned to area code 410. Normally, when an area code is split, the largest city in the old numbering plan area retains the existing area code—in this case, Baltimore. In this case, however, Bell Atlantic wanted to spare the large number of federal agencies on the Maryland side of metropolitan Washington from the expense and disruption of changing their numbers.

First overlay

This was intended as a long-term solution, but within four years 301 was close to exhaustion due to the proliferation of cell phones and pagers, especially in the Washington suburbs. In order to solve this problem, area code 240 was introduced on June 1, 1997, as the state's first

overlay area code In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to a geographic numbering plan area (NPA). Area code overlays are implemented in territories of the North American Numbering Pla ...

. Overlays were a new concept at the time, and met with some resistance due to the requirement for

ten-digit dialing Ten-digit dialing is a telephone dialing procedure in the countries and territories that are members of the North American Numbering Plan (NANP). It is the practice of including the area code of a telephone number when dialing to initiate a telep ...

. It was decided to create an overlay rather than split the region into two new regions in order to avoid assigning a new area code to 1.2million existing phone numbers. At the time, it was predicted that it would take until 2008 to exhaust area code 240.

Second overlay

In September 2022, it was projected that the 301 and 240 area codes would be exhausted between April and June 2023. The

North American Numbering Plan Administrator The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international calling ...

has assigned area code 227 as an additional overlay for the region.Duffy, Ken (September 28, 2022).
New Area Code Coming to Parts of Maryland
. '' WBAL''. Phone numbers with area code 227 only begin to be assigned on June 14, 2023. However, existing phone numbers with area codes 301 and 240 will not change, even after 227 enters service. Existing phone numbers will not change.

Service area

The counties served by area codes 301 and 240 include all of Allegany,

Charles Charles is a masculine given name predominantly found in English language, English and French language, French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic, Proto-Germanic name (in runic alphabet) or ''*k ...

, Garrett, Montgomery, Prince George's, St. Mary's and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

counties, most of Frederick County, western Howard County,, and slivers of southwestern Carroll County and western

Anne Arundel County Anne Arundel County (; ), also notated as AA or A.A. County, is located in the U.S. state of Maryland. As of the 2020 United States census, its population was 588,261, an increase of just under 10% since 2010. Its county seat is Annapolis, whi ...

. Local calls require ten-digit dialing (area code + number, leading "1" is not required).

Notes

References

External links

301 Area Code in Maryland240 Area Code in Maryland
{{DEFAULTSORT:Area Codes 240 And 301 240 and 301 240 Telecommunications-related introductions in 1947