Illinois · Central Time
773 Area Code
The 773 area code is a telephone area code in Illinois, covering Chicago and the surrounding area. It lies in the Central Time zone.
Last updated June 5, 2026
Where is the 773 area code?
773 serves Chicago and nearby communities in Illinois. In the wider directory it sits in the Midwest region.
Overlay codes serving Chicago
Chicago is served by an overlay of 3 area codes: 312, 773, 872. 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 Chicago numbers are no longer tied to a single prefix.
History of the 773 area code
773 was introduced as an overlay to relieve number exhaustion in the Chicago area, adding capacity on top of 312 rather than splitting the region. Overlays let existing customers keep their numbers while new lines draw from the added code. Learn more in our overlay guide.
Is 773 a scam or spam risk?
773 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 773 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 7XX 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
773 area code FAQ
Where is the 773 area code?
The 773 area code is in Illinois, serving Chicago and the surrounding area in the Midwest region.
What time zone is 773 in?
773 is in the Central Time zone.
Do I have to dial 10 digits for 773?
Yes. Because Chicago is an overlay area, you must dial the full 10-digit number (area code + 7 digits) for every call.
Is 773 a toll-free or premium code?
No. 773 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.