Illinois Area Codes, United States

Find the real owner of someone with a 217 and 447, 309 and 312, 618,

630 and 331, 708, 773, 779 and 815, 224 and 847 Illinois area codes.

Illinois area code

Illinois was the twenty-first state to join the Union in 1818. The Land of Lincoln is home to some 13 million residents, and 14 Illinois area codes connect these residents. Illinois area codes are useful to identify a caller’s city or town in Illinois. But that’s where it ends. If you want additional details, you will need to check an Illinois phone numbers database.

Before cellphones became popular in the late 1990s, phone calls happened on switchboards. Essentially, if you needed to call someone, you first dialed an operator who manually routes your call to the recipient. Despite its initial success, manual switchboards could not handle a high volume of calls. Besides, there was the issue of privacy – an operator could listen in on conversations.

Given these issues, a numbering plan that used area codes soon replaced switchboards and made calls a straightforward process. More importantly, it also improved callers’ privacy since humans did not route phone calls.

Take your typical ten-digit Springfield phone number, 217-NYY-XXXX, and think of it as a physical address.

217 is the area code, representing a small geographical area within Illinois – in this case, Springfield. The next three digits, NYY, make up the prefix code. This prefix code helps narrow down the phone number owner to a particular town or street in Springfield.

The last four digits, XXXX, is the line number, a unique identifier for every phone number owner. If a phone number were a house address, the line number would be a house number, flat number, or room number.

Illinois started with four area codes in 1947. As the state’s population grew, Illinois has since created 14 Illinois area codes using overlay and geographic split. Residents retained old area codes if they wish, but they can always opt for new area codes in their city or town.

Besides connecting you with the person you wish to call, area codes also let you identify an unknown caller’s location. But you will need a reverse phone search to get more specific with the prefix code and line number.  

Several persons can have the same area code if they live in the same area. Likewise, several persons can have the same prefix code if they are neighbors. However, no two persons can have the same line number. With a phone number search on an Illinois phone numbers database, you can get a phone number owner’s information. This includes the caller’s physical address, social media profiles, and relevant public records.

CountyFIPS codeCounty seatEstablishedPopulationArea
Adams County011Quincy182565,691855 sq mi
Alexander County003Cairo18196,060235 sq mi
Bond County005Greenville181716,630380 sq mi
Boone County007Belvidere183753,577280 sq mi
Brown County009Mount Sterling18396,556305 sq mi
Bureau County011Princeton183732,993869 sq mi
Calhoun County013Hardin18254,802253 sq mi
Carroll County015Mount Carroll183914,312445 sq mi
Cass County017Virginia183712,260375 sq mi
Champaign County019Urbana1833209,983996 sq mi
Christian County021Taylorville183932,661709 sq mi
Clark County023Marshall181915,596501 sq mi
Clay County025Louisville182413,253468 sq mi
Clinton County027Carlyle182437,639474 sq mi
Coles County029Charleston183050,885508 sq mi
Cook County031Chicago18315,180,493944 sq mi
Crawford County033Robinson181618,807443 sq mi
Cumberland County035Toledo184310,808345 sq mi
DeKalb County037Sycamore1837104,143631 sq mi
DeWitt County039Clinton183915,769397 sq mi
Douglas County041Tuscola185919,479416 sq mi
DuPage County043Wheaton1839928,589327 sq mi
Edgar County045Paris182317,360623 sq mi
Edwards County047Albion18146,392222 sq mi
Effingham County049Effingham183134,208478 sq mi
Fayette County051Vandalia182121,416716 sq mi
Ford County053Paxton185913,264485 sq mi
Franklin County055Benton181838,701408 sq mi
Fulton County057Lewistown182334,844865 sq mi
Gallatin County059Shawneetown18125,058322 sq mi
Greene County061Carrollton182113,044543 sq mi
Grundy County063Morris184150,972418 sq mi
Hamilton County065McLeansboro18218,163434 sq mi
Hancock County067Carthage182517,844793 sq mi
Hardin County069Elizabethtown18393,910177 sq mi
Henderson County071Oquawka18416,709378 sq mi
Henry County073Cambridge182549,090822 sq mi
Iroquois County075Watseka183327,6041,117 sq mi
Jackson County077Murphysboro181657,419584 sq mi
Jasper County079Newton18319,611494 sq mi
Jefferson County081Mount Vernon181937,820571 sq mi
Jersey County083Jerseyville183921,847369 sq mi
Jo Daviess County085Galena182721,366600 sq mi
Johnson County087Vienna181212,456343 sq mi
Kane County089Geneva1836534,216519 sq mi
Kankakee County091Kankakee1853110,024676 sq mi
Kendall County093Yorkville1841127,915320 sq mi
Knox County095Galesburg182550,112716 sq mi
Lake County097Waukegan1839700,832443 sq mi
LaSalle County099Ottawa1831109,4301,135 sq mi
Lawrence County101Lawrenceville182115,765372 sq mi
Lee County103Dixon183934,223724 sq mi
Livingston County105Pontiac183735,7611,043 sq mi
Logan County107Lincoln183928,925618 sq mi
Macon County115Decatur1829104,712580 sq mi
Macoupin County117Carlinville182945,313862 sq mi
Madison County119Edwardsville1812264,461716 sq mi
Marion County121Salem182337,620572 sq mi
Marshall County123Lacon183911,534386 sq mi
Mason County125Havana184113,565539 sq mi
Massac County127Metropolis184314,080237 sq mi
McDonough County109Macomb182629,955589 sq mi
McHenry County111Woodstock1836308,570603 sq mi
McLean County113Bloomington1830172,8281,183 sq mi
Menard County129Petersburg183912,288314 sq mi
Mercer County131Aledo182515,601561 sq mi
Monroe County133Waterloo181634,335385 sq mi
Montgomery County135Hillsboro182128,601703 sq mi
Morgan County137Jacksonville182333,976568 sq mi
Moultrie County139Sullivan184314,717335 sq mi
Ogle County141Oregon183650,923758 sq mi
Peoria County143Peoria1825180,621618 sq mi
Perry County145Pinckneyville182721,174441 sq mi
Piatt County147Monticello184116,396439 sq mi
Pike County149Pittsfield182115,611831 sq mi
Pope County151Golconda18164,212368 sq mi
Pulaski County153Mound City18435,463199 sq mi
Putnam County155Hennepin18255,740160 sq mi
Randolph County157Chester179532,106575 sq mi
Richland County159Olney184115,763360 sq mi
Rock Island County161Rock Island1831143,477427 sq mi
Saline County165Harrisburg184723,906379 sq mi
Sangamon County167Springfield1821195,348868 sq mi
Schuyler County169Rushville18256,907437 sq mi
Scott County171Winchester18394,926250 sq mi
Shelby County173Shelbyville182721,741758 sq mi
St. Clair County163Belleville1790261,059657 sq mi
Stark County175Toulon18395,427288 sq mi
Stephenson County177Freeport183744,753564 sq mi
Tazewell County179Pekin1827132,328646 sq mi
Union County181Jonesboro181816,841413 sq mi
Vermilion County183Danville182676,806898 sq mi
Wabash County185Mount Carmel182411,549223 sq mi
Warren County187Monmouth182517,032542 sq mi
Washington County189Nashville181813,995562 sq mi
Wayne County191Fairfield181916,332713 sq mi
White County193Carmi181513,665494 sq mi
Whiteside County195Morrison183655,626684 sq mi
Will County197Joliet1836692,310835 sq mi
Williamson County199Marion183967,056420 sq mi
Winnebago County201Rockford1836284,081513 sq mi
Woodford County203Eureka184138,463527 sq mi