List of North American Numbering Plan Area Codes - 300-399

300-399

300: not used

301: Maryland (Silver Spring, Washington, D.C., suburbs, all counties which touch the Potomac River, and the towns of Hagerstown, Frederick, Rockville, Cumberland, and land line telephones in all of western Maryland)

  • Originally covered all of Maryland; split in 1991 to create 410.
  • Overlain by 240 in 1997.
  • To be overlain with 227 in the future.

302: Delaware (all)

303: Colorado (Denver, Boulder, Longmont, Aurora, Golden, Limon, Centennial; central Colorado)

  • Originally covered all of Colorado; split to create 719 (1988) and 970 (1995).
  • Overlain by 720 in 1998.

304: West Virginia

  • Overlain by 681 in 2009.

305: Florida (all of Miami-Dade County and the Florida Keys: Miami, Miami Beach, Homestead, Coral Gables, Marathon, Key West.

  • Originally covered all of Florida; split to create 813 (1953), 904 (1965), 407 (1988), 954 (1995).
  • Partial overlay by 786 in 1998, in Miami-Dade County only. Complete overlay including the Keys in 2008.

306: Saskatchewan (all)

  • To be overlain by area code 639 in May, 2013.

307: Wyoming (all)

308: Nebraska (North Platte, Scottsbluff, McCook, Kearney, Grand Island, and all of western Nebraska)

  • Created in 1954 by split from 402.

309: Illinois (Peoria, Bloomington, Moline, Rock Island, Galesburg, and west-central Illinois)

  • Created in 1957 from parts of 217 and 815.

310: California (Beverly Hills, Brentwood, Malibu, Pacific Palisades, Redondo Beach, Santa Monica, Torrance, Santa Catalina Island, and the coastal areas of Los Angeles County)

  • Created in 1991 by split from 213.
  • Split in 1997 to create 562.
  • Overlain by 424 in 2006.

311: Local or government non-emergency use; City Hall in some localities.

312: Illinois (downtown Chicago)

  • Split to create 708 (1989) and 773 (1996).
  • Overlain by 872 in 2009.

313: Michigan (Dearborn, Detroit and its inner enclaves of Hamtramck and Highland Park)

  • Split to create 810 (1993) and 734 (1997).

314: Missouri (St. Louis, St. Louis County, Florissant, Crestwood, Hazelwood, Kirwood, and surrounding sububs of St. Louis)

  • Split in 1950 to create part of 417.
  • Split to create 573 (1996) and 636 (1999).

315: New York (Syracuse, Utica, Watertown, and north-central New York)

  • Split in 1954 to create part of 607.

316: Kansas (Wichita metropolitan area, McConnell Air Force Base, Augusta, El Dorado, Mulvane, and Hutchinson)

  • Split in 2001 to create 620.

317: Indiana (Indianapolis and immediate metro area including Carmel, Fishers, Noblesville, Greenwood, Mooresville, Beech Grove, Plainfield, Avon, and Brownsburg.)

  • Split to create 219 (1948) and 765 (1997).

318: Louisiana (Shreveport, Monroe, Alexandria, Fisher, Tallulah, and most of northern Louisiana)

  • Created in 1957 by split from 504.
  • Split in 1999 to create 337.

319: Iowa (Cedar Rapids, Waterloo, Burlington, Iowa City, east-central, and southeastern Iowa)

  • Split in 2001 to create 563.

320: Minnesota (St. Cloud, Alexandria, Morris, Hutchinson, Sandstone, Appleton, Willmar and central Minnesota)

  • Created in 1996 by split from 612.

321: Florida (Orlando, Cocoa, Melbourne, Rockledge, Titusville, St Cloud, and east-central Florida). This Area partially overlies 407, and this is the exclusive code for the Space Coast (Cape Canaveral, Titusville, Cocoa, Cocoa Beach, Satellite Beach, Melbourne, Merritt Island, Patrick Air Force Base, Palm Bay.)

  • Created in 1999.
  • Mnemonic: The final digits of a rocket countdown.

322: not used

323: California (part of the City of Los Angeles excluding Downtown Los Angeles, Western Los Angeles, Westwood, the San Fernando Valley, Florence, and Montebello)

  • Created in 1998 by split from 213.

324: not used

325: Texas (Abilene, San Angelo, Sweetwater, Snyder)

  • Created in 2003 by split from 915.

326: not used

327: Arkansas (Texarkana, Jonesboro, Pine Bluff, and most of southern, eastern, and northeastern Arkansas)

  • Future overlay of 870, to be effective in 2013.

328–329: not used

330: Ohio (Akron, Canton, Youngstown, Warren, and most of northeastern Ohio)

  • Created in 1997 by split from 216.
  • Overlain by 234 in 2000.

331: Illinois (Aurora, Naperville, Oswego, and other western suburbs of Chicago)

  • Overlain on 630 in 2007.

332–333: not used

334: Alabama (Montgomery, Auburn, Dothan, Enterprise, Eufaula, Opelika, Phenix City, Selma, Tuskegee and most of southeastern Alabama)

  • Created in 1995 by split from 205.
  • Split in 2001 to create 251.

335: not used

336: North Carolina (Greensboro, Winston-Salem, Wilkesboro, Roxboro, and most of northwestern North Carolina)

  • Created in 1997 by split from 910.

337: Louisiana (Lafayette, Lake Charles, Leesville, New Iberia, Opelousas, and most of southwestern Louisiana)

  • Created in 1999 by split from 318.

338: not used

339: Massachusetts

  • Overlain on 781 in 2001.

340: the U.S. Virgin Islands (all)

  • Created in 1997 by split from 809.

341 is assigned for numbering relief to 510 (east shore of San Francisco Bay, California), but no date has been scheduled for this to be implemented.

342: not used

343: Ontario: (Ottawa metropolitan area and southeastern Ontario)

  • Overlain on 613 in 2010.

344: not used

345: the Cayman Islands (all)

  • Created in 1996 by split from 809.

346: not used

347: New York City

  • Overlain on 718 (and part of 917) in 1999.
  • Overlain again by 929 in 2011.

348–350: not used

351: Massachusetts

  • Overlain on 978 in 2001.

352: Florida (Gainesville, Ocala, Inverness, Dunnellon, and part of central Florida)

  • Created in 1995 by split from 904.
  • Mnemonic: FLA

353–359: not used.

  • 356 was authorized for use as a relief area code in New Jersey; however, 356 was replaced by 862 since this proposed code was condidered to be too similar to southern New Jersey's Area code 856

360: State of Washington (Olympia, Vancouver, Bellingham, Bremerton, Port Angeles, Aberdeen, and most of western Washington except the Seattle metropolitan area)

  • Created in 1995 by split from 206.

361: Texas (Corpus Christi, Victoria, George West, and much of South Texas)

  • Created in 1999 by split from 512.

362–363: not used

364: Kentucky—Planned relief of 270. Split plan canceled in December 2010, may be revived in the future as an overlay.

365: Ontario—overlay of Area codes 905 and 289, scheduled to be created on March 25, 2013

  • Area code 742 reserved as a fourth code for the region.

366–368: not used

369 is assigned for numbering relief to 707 (northwest California), but no date has been scheduled for it to go into effect.

370–379: block reserved in case consecutive numbers are ever needed

380 is assigned for area code relief to 614 in Ohio but no date has been scheduled for this to be implemented. (Four thousands blocks are assigned to a switch in Palm Coast, Florida; and one thousands block to a switch in Shreveport, Louisiana.)

381–384: not used

385: Utah (Counties of Davis, Morgan, Salt Lake, Utah, and Weber along the Wasatch Front, including the cities of Salt Lake City, Ogden, and Provo)

  • Overlain on 801 in 2009.

386: Florida (Daytona Beach, Lake City, Live Oak, Crescent City, and parts of northeastern Florida)

  • Created by split from 904 in 2001.
  • Mnemonic: FUN

387: Reserved as a fourth area code to overlay 416 for the city of Toronto, Ontario, Canada with no set date for implementation

388-389: not used

390–399: Reserved for potential North American Numbering Plan expansion

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