773 Phone Number Lookup | Illinois Area Code

Where Is Area Code 773 Located?

Phone numbers with the 773 prefix originate from Chicago, Illinois, specifically the parts of the city outside of the downtown area known as the Loop and its innermost neighborhoods.

Major Cities:

• Chicago

Overlay System

Area code 773 operates within an overlay system with other area codes. Originally, Chicago was served by area code 312 . Area code 773 was introduced on October 12, 1996, to serve Chicago outside the downtown area, while 312 continued to serve the Loop and innermost neighborhoods. On August 10, 2007, it was announced that area code 872 would overlay both area codes 312 and 773, going into service on November 7, 2009. This means that 312, 773, and 872 all serve the same geographic region.

Area Code 773 Location Map

Area code 773 is a general purpose code which was placed in service on October 12, 1996.

Phone Number Prefixes and Carriers

Our Illinois phone number lookup for the 773 area code analyzes the three-digit prefix to identify the initially assigned telecommunications company and rate center. This prefix code data may help to determine the U.S. carrier, Illinois geographic region, and local calling area associated with the phone number.

Phone numbers follow the following structure under the North American Numbering Plan:

• NPA- area code (where the number was originally assigned)
• NXX - Central office code that locates the specific neighborhood and identifies the service provider
• XXXX - Subscriber number identifies the individual phone line within that local exchange

Understanding the area code can help you determine if a call is local to your area. However, keep in mind that due to mobile number portability and VoIP services, the caller may be anywhere in the United States, so it’s best to search for the most recent phone number details.

Prefixes by Company

Carrier names have been updated from their original FCC assignments to reflect current companies following mergers, acquisitions, and rebranding. Updates were determined using AI-assisted research and may not be accurate or reflect up to date changes. This data is provided without warranties of accuracy or completeness.

Prefixes by Rate Center

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