Area Code 312
In 1940, Bell Laboratories and AT&T put forward an area code system. Even after being established in the year 1940, this area code came into effect much later in the year 1947. This area coding system was popularly known as the NANP or North American Numbering Plan.
In the year 1947, states as well as provinces that were associated with only one area code were offered three digit numbers as area codes with zero as the middle digit. For instance, Florida was offered area code 305 whereas Connecticut was offered area code 203. States as well as provinces that were associated with more than a single area code were allocated three digit numbers as area codes with one as their middle digit. For instance, the area code of a certain areas of California was offered 213 whereas a few areas of California were offered 916. In the like manner the area code of some regions of New York was offered the area code 518 and some region of New York was assigned the area code 212. The first as well as the third digits were assigned only after taking into account the population density of the city as well as the region that is grouped under a specific area code. The areas that were densely populated were assigned the lowest numbers as area codes.
Area code 312 includes the Chicago Loop as well as the regions in Chicago, Illinois. This area code is approximately encompassed by North Avenue on the Western Avenue on the west, 31st Street on the south as well as Lake Michigan on the east. Taking into consideration the size, area code 312 is believed to be one amongst the smallest of all area codes that includes only a couple of square miles. Area code 312 is believed to be one amongst the first area codes that were introduced in the year 1947.
Till 1989, area code 312 took into consideration the major portion of the metropolitan area of Chicago and area code 708 took over the suburban areas.
Area Code 312 serves the following states:
Illinois
Area Code 312 serves the following counties:
Champaign, Cook, Dupage, Kane, Lake, Marion, Mchenry, Will
Area Code 312 serves the following Cities
Algonquin, Arlington heights, aurora, Barrington, Bensenville, blue island, Brookfield, buffalo grove, Champaign, Chicago, Cicero, Clarendon hills, Country Club hills, Crystal lake, Darien, Deerfield, Des Plaines, Elmwood park, Evanston, Glenview, Harwood Heights, Hinsdale, Indianapolis, Lake Zurich, Lincolnshire, Lombard, Medinah, Northbrook, Oak brook, Oak lawn, Oak park, Park ridge, Plainfield, Prospect heights, Rolling meadows, Schaumburg, Villa park, Western springs, Wheeling, Willowbrook
Area code 312 records an estimated population of 2, 926, 848. In other words, nearly 2, 926, 848 people are registered with the phone services of this area code.
The carriers for the area code 312 are as follows:
Southwestern Bell Mobile Systems
Adbeep
American Messaging
Geotek Communications
United States Cellular Corp
Arch Wireless Holdings
Heartland Communications
Metrocall
Broadwing Communications
T Mobile Usa
Blue Licenses Holding
Illinois Bell Tel Co
Sprint Spectrum
Level 3 Communications
Cellular Paging Usa
Multi Computer Systems
Beepermart