Illinois · Central Time
815 Area Code
The 815 area code is a telephone area code in Illinois, covering Rockford and the surrounding area. It lies in the Central Time zone.
Last updated June 5, 2026
Where is the 815 area code?
815 serves Rockford and nearby communities in Illinois. In the wider directory it sits in the Midwest region.
Overlay codes serving Rockford
Rockford is served by an overlay of 2 area codes: 779, 815. Because more than one code covers the same area, 10-digit dialing is mandatory — you must dial the area code for every local call. New phone lines may be assigned any of these codes, so Rockford numbers are no longer tied to a single prefix.
History of the 815 area code
815 is one of the original area codes assigned in 1947, when AT&T and Bell Laboratories created the North American Numbering Plan and divided the country into the first 86 numbering plan areas. It has served the Rockford area ever since.
Is 815 a scam or spam risk?
815 is a legitimate geographic area code, not a premium or toll line, so a call from it costs you nothing extra. That said, scammers frequently spoof real local area codes to look familiar on caller ID. A genuine 815 number on your screen is no guarantee the caller is local or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Other Illinois area codes
Explore more
See every code in Illinois, compare codes across the Midwest region, or view all Central Time codes. You can also browse the 8XX block or the complete numeric list of US area codes.
New to how this all works? Start with how area codes work, then read up on overlays, 10-digit dialing, and spam & scam-risk codes. To check another number, use the area code lookup tool.
Quick answers
815 area code FAQ
Where is the 815 area code?
The 815 area code is in Illinois, serving Rockford and the surrounding area in the Midwest region.
What time zone is 815 in?
815 is in the Central Time zone.
Do I have to dial 10 digits for 815?
Yes. Because Rockford is an overlay area, you must dial the full 10-digit number (area code + 7 digits) for every call.
Is 815 a toll-free or premium code?
No. 815 is a standard geographic area code, so calling it costs the same as any local or long-distance call on your plan. Toll-free calls use 800, 888, 877, 866, 855, 844 or 833.