Area code 312 is a telephone area code in the North American Numbering Plan for the city of Chicago, including downtown, the Chicago Loop, and its immediate...

and its suburbs used area code 312. In 1989, area code 708 was created for the suburbs, leaving the city in area code 312. By the mid-1990s, Chicago's continued...

of area code 312. It once served almost all of Chicago's suburbs in Illinois. In 1996, its numbering plan area was reduced in a three-way area code split...

geographical area of Chicago except the downtown Chicago Loop, which is in area code 312. 815/779: Northern Illinois outside of the immediate Chicago area including...

Windcrest. Area codes 210 and 726 are enclave area codes, similar to area code 312 in Chicago, area code 316 in Wichita, Kansas, area codes 385/801 in...

plan area that comprises those of area codes 312 and 773. The overlay commenced service on November 7, 2009. It is the third overlay area code in the...

geographic numbering plan areas (NPAs). Each NPA is identified by one or more numbering plan area codes (NPA codes, or area codes), consisting of three digits...

metro area was served by a single area code, 312, which abutted the 815 area code. In 1988 the 708 area code was introduced and the 312 area code became...

Mexico are provided by a telephone numbering plan that specifies groups of area codes for the following regions: Telephone numbers in Mexico "Telephone numbering...

2007, area code 331 began overlaying area code 630, making ten-digit dialing mandatory in the area. The Illinois side of the Chicago area–312/773/872...

Area codes 541 and 458 are telephone area codes in the North American Numbering Plan (NANP) for most of the U.S. state of Oregon, excluding only the northwestern...

Area codes 905, 289, 365, and 742 are telephone area codes in the North American Numbering Plan (NANP) for the Golden Horseshoe region that surrounds Lake...

Area codes 847 and 224 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of Illinois. The numbering plan area (NPA)...

Area code 563 is a telephone area code for the east central and northeast corner of the state of Iowa, and includes most of the Iowa side of the Quad Cities...

Area codes 815 and 779 are telephone area codes in the North American Numbering Plan (NANP) for most of northern Illinois outside the Quad Cities areas...

Area codes 617 and 857 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of Massachusetts, serving the city of Boston...

Area code 604 is a telephone area code in the North American Numbering Plan for the southwestern corner of British Columbia, Canada. The numbering plan...

Area codes 519, 226, 548, and 382 are overlay telephone area codes in the North American Numbering Plan (NANP) for most of southwestern Ontario. Area...

Area code 603 is the sole area code for the U.S. state of New Hampshire in the North American Numbering Plan (NANP). It was created as one of the original...

Area code 765 is a telephone area code in the North American Numbering Plan (NANP) for the central part of the U.S. state of Indiana. The numbering plan...

Area code 606 is a telephone area code in the North American Numbering Plan for the eastern half of south-central and the eastern part of the Commonwealth...

Area code 780 is a telephone area code in the North American Numbering Plan (NANP) for the Canadian province of Alberta. The numbering plan area comprises...

Area codes 778, 236, 672, and 257 are telephone overlay area codes in the North American Numbering Plan (NANP) for the Canadian province of British Columbia...

Area code 250 is a telephone area code in the North American Numbering Plan (NANP) for the Canadian province of British Columbia outside the Lower Mainland...

Area codes 608 and 353 are telephone area codes in the North American Numbering Plan for much of southwestern Wisconsin, including the state capital city...

Area code 218 is a telephone area code in the North American Numbering Plan (NANP) for the northern part of the U.S. state of Minnesota. It is assigned...

Highland Park, Illinois. The name of the event is in reference to area code 312, the area code of downtown Chicago. Fourteen matches were contested at the event...

Area code 701 is a telephone area code in the North American Numbering Plan (NANP) for the U.S. State of North Dakota. It is one of the 86 original North...

Area code 403 is a telephone area code in the North American Numbering Plan (NANP) for the Canadian province of Alberta. The numbering plan area encompasses...

Area codes 204, 431, and 584 are telephone area codes in the North American Numbering Plan (NANP) for the Canadian province of Manitoba. Area code 204...