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 environs.

Where is area code 312? Area code 312 serves part of Chicago, IL. It overlaps coverage areas with area code 872.

The 312 area code is a geographic telephone area code serving downtown Chicago and the immediate surrounding areas in Cook County, Illinois. Established in 1947 as part of the …

Dec 26, 2025 · Area code 312 is located in Illinois. Get area code location and dialing plans for all phone prefixes in area code 312.

3 days ago · 312 is an area code located in the state of Illinois, US. The largest city it serves is Chicago. Find out where 312 area code zone from, which states, counties and cities it covers. …

Find 312 area code details including city, time zone, and map. Lookup area code 312 phone number, name, and location.

The 312 Area Code is located in the state of Illinois. Area Code 312 is one of the 269 three-digit telephone area codes in the USA. It covers roughly 7,859,286 unique phone numbers and …

Area code 312 serves the heart of Chicago, Illinois, covering downtown and nearby neighborhoods along Lake Michigan. It includes the city’s core business and cultural districts, …

Area code 312 serves the entire state of Illinois in United State, providing phone services to both residential and business users. It covers urban, suburban, and rural areas alike, ensuring …

We've have collected info regarding the area code 312 in this page, which helps with a phone number search. Here, you'll find the location, time zone, cities and other information regarding …