Joliet, Illinois

Where Is Area Code 815?

Area code 815 is in northern Illinois. It serves a large part of the state outside the Chicago core, including Joliet and many communities west, southwest, and northwest of the city of Chicago. The area reaches from the Rockford region to the Illinois River Valley and parts of north-central Illinois.

Major cities in area code 815 include Joliet, Rockford, DeKalb, Freeport, McHenry, Ottawa, and Dixon. It covers all or parts of counties such as Will, Winnebago, DeKalb, LaSalle, McHenry, Ogle, Lee, Bureau, and Stephenson counties. The area code also serves many smaller communities across a broad rural and suburban region.

Notable places in the 815 region include the city of Joliet, the Rock River, the Illinois River, and Starved Rock State Park near Utica. Northern Illinois University in DeKalb is also within this numbering area. The region includes both industrial cities and farming communities.

History of Area Code 815

Area code 815 was created in 1947 as one of the original North American area codes. It was assigned to northern Illinois outside the immediate Chicago area when the North American Numbering Plan first took effect. That makes 815 one of Illinois' long-established geographic area codes.

Area code 815 later gained an overlay. Area code 779 was added as an overlay to the same region in 2007 to provide more phone numbers. Since that change, 10-digit dialing has applied across the 815 and 779 service area.

Key Facts About Area Code 815

• Area code 815 is in the state of Illinois, and Joliet is one of its best-known cities.
• Area code 815 is in the Central Time Zone.
• Area code 815 was established in 1947 as one of the original area codes in the North American Numbering Plan.
• Area code 815 is a geographic area code, not a toll-free code.
• Area code 779 overlays area code 815, and the overlay began in 2007.
• Major cities in the 815 region include Joliet, Rockford, DeKalb, Freeport, McHenry, Ottawa, and Dixon.
• Northern Illinois University in DeKalb is located within the 815 area code region.
• Starved Rock State Park near Utica is a notable landmark within the broader 815 service area.

Frequently Asked Questions

What state is area code 815 in?

Area code 815 is in Illinois.

What major cities use area code 815?

Major cities that use area code 815 include Joliet, Rockford, DeKalb, Freeport, McHenry, Ottawa, and Dixon.

Is area code 815 a toll-free number?

No, area code 815 is a geographic area code.