Area Code 309 and 312

Area code 309 map
Area code 312 map

The History of Area Codes 309 and 312

The story of area codes in Illinois, specifically Area Codes 309 and 312, is a testament to this rich heritage. These numeric identifiers, three digits in length, are more than just codes; they represent the evolution of telecommunication in Illinois, mirroring the state’s growth and urban-rural dynamics. In Illinois, the first area code was 312, designated as part of the initial rollout of the NANP

Area Code 312 encompassed the entire state, reflecting the simplicity of telecommunications infrastructure in the mid-20th century. The first split occurred in 1957 when Regional Code 309 was introduced to serve southern and western Illinois. Area Code 312 continued to serve the Chicago metropolitan area, the state’s most populous and economically dynamic region. Thus, the two area codes, 312 and 309, began symbolizing Illinois’ urban-rural divide, reflecting geographical realities and socio-economic differences.

Area code 861 was added to the numbering plan area on February 24, 2023, in formation of an overlay. It was an alternative to splitting the area geographically, which could cause disruption and confusion. Today, the area codes in Illinois, such as 309 and 312, tell a story of the state’s growth, changes in telecommunications technology, and the ongoing need to adapt to increasing demands for connectivity.

Area codes 309 and 312 generally belong to callers from these municipalities in Illinois

Abingdon, IL
Adair, IL
Albany, IL
Aledo, IL
Alexis, IL
Alpha, IL
Altona, IL
Anchor, IL
Andalusia, IL
Andover, IL
Annawan, IL
Armington, IL
Arrowsmith, IL
Astoria, IL
Atkinson, IL
Atlanta, IL
Avon, IL
Bardolph, IL
Bath, IL
Bellflower, IL
Benson, IL
Biggsville, IL
Bishop Hill, IL
Blandinsville, IL
Bloomington, IL
Bradford, IL
Brimfield, IL
Bryant, IL
Buda, IL
Bushnell, IL
Cambridge, IL
Canton, IL
Carbon Cliff, IL
Carlock, IL
Chicago, IL
Chillicothe, IL
Coal Valley, IL
Colchester, IL
Colfax, IL
Colona, IL
Congerville, IL
Cooksville, IL
Cordova, IL
Creve Coeur, IL
Cuba, IL
Danvers, IL
Deer Creek, IL
Delavan, IL
Downs, IL
Dunfermline, IL
Dunlap, IL
East Galesburg, IL
East Moline, IL
East Peoria, IL
Easton, IL
El Paso, IL
Ellisville, IL
Ellsworth, IL
Elmwood, IL
Erie, IL
Eureka, IL
Fairview, IL
Farmer City, IL
Farmington, IL
Forest City, IL
Galesburg, IL
Galva, IL
Geneseo, IL
Gilson, IL
Gladstone, IL
Glasford, IL
Good Hope, IL
Goodfield, IL
Green Valley, IL
Gridley, IL
Hampton, IL
Hanna City, IL
Havana, IL
Henderson, IL
Henry, IL
Heyworth, IL
Hillsdale, IL
Hooppole, IL
Hopedale, IL
Hudson, IL
Industry, IL
Ipava, IL
Joy, IL
Keithsburg, IL
Kewanee, IL
Kilbourne, IL
Kingston Mines, IL
Kirkwood, IL
Knoxville, IL
La Fayette, IL
La Rose, IL
Lacon, IL
Le Roy, IL
Lewistown, IL
Lexington, IL
Little York, IL
Littleton, IL
Liverpool, IL
London Mills, IL
Mackinaw, IL
Macomb, IL
Manito, IL
Mapleton, IL
Maquon, IL
Marietta, IL
Matherville, IL
Media, IL
Metamora, IL
Milan, IL
Mineral, IL
Minier, IL
Minonk, IL
Moline, IL
Monmouth, IL
Morton, IL
Neponset, IL
New Boston, IL
Normal, IL
Norris, IL
North Henderson, IL
Oneida, IL
Oquawka, IL
Orion, IL
Pekin, IL
Peoria, IL
Peoria Heights, IL
Plymouth, IL
Port Byron, IL
Prairie City, IL
Princeville, IL
Rapids City, IL
Raritan, IL
Reynolds, IL
Rio, IL
Roanoke, IL
Rock Island, IL
Rome, IL
Roseville, IL
Saint Augustine, IL
Saint David, IL
San Jose, IL
Saybrook, IL
Sciota, IL
Seaton, IL
Secor, IL
Sherrard, IL
Silvis, IL
Smithfield, IL
South Pekin, IL
Sparland, IL
Stanford, IL
Stronghurst, IL
Table Grove, IL
Toluca, IL
Topeka, IL
Toulon, IL
Towanda, IL
Tremont, IL
Varna, IL
Vermont, IL
Victoria, IL
Viola, IL
Wapella, IL
Washburn, IL
Washington, IL
Wataga, IL
Waynesville, IL
Williamsfield, IL
Woodhull, IL
Wyoming, IL
Yates City, IL

309 and 312 Area Codes FAQs

Q: What area codes are 309 and 312?

A: Area codes 309 and 312 are part of the North American Numbering Plan (NANP), established to facilitate direct dialing for long-distance calls.

Q: When 309 and 312 area codes were created?

A: Area Code 312 was established in 1947. The creation of Area Code 309 happened in 1957 when the state was split to accommodate the growing demand for telephone services.         

Q: Where are area codes 309 and 312?

A: Area Code 309 covers central and western parts of Illinois, including Peoria, Bloomington, and Moline. Area Code 312 serves the downtown area of Chicago, one of the biggest business districts in the state.

Q: Who needs to dial 1 before the 309 and 312 area codes?

A: People making long-distance calls within the United States, or international calls from outside the United States, typically need to dial 1 before the area code. Dialing in a different area code within the NANP is also necessary.

Q: Why are area codes like 309 and 312 important?

A: Area codes like 309 and 312 are essential for routing phone calls to the correct geographic areas. They also provide a form of identity to the regions they represent, reflecting their history, population distribution, and socio-economic dynamics.

Q: Are area codes 309 and 312 overlaid with another area code?

A: The city of Chicago will have a new area code 872 which is the city’s third area code and will overlay the current area of area codes 312 and 773. The New 861 Area Code is Coming to the Illinois 309 Area Code Region

Q: What other area codes are nearby area codes 309 and 312?

A: Area Codes 708, 847, and 630 are nearby Area Code 312 in the Chicago metropolitan area. Area Code 217 is adjacent to 309, covering the central part of Illinois, including cities like Springfield and Champaign.

Q: Can I obtain a phone number with Area Codes 309 and 312?

A: Yes, you can obtain a phone number with Area Codes 309 and 312. The exact process depends on the phone service provider you choose.

Q: What is the population of the area covered by area codes 309 and 312?

A: The exact population varies over time due to migration and other demographic changes. As of 2021, the population in the regions covered by Area Code 309 was around 1.1 million. Area Code 312 covers downtown Chicago, a dense business district. According to the last census, the population of Chicago was 2,741,730.

Q: What is the timezone for Area Codes 309 and 312?

A: Both Area Codes 309 and 312 are in the Central Time Zone.

Find the real owner of someone with a 217 and 447309 and 312, 618630 and 331708773779 and 815, 224 and 847 area code