The nation’s third-largest city, Chicago runs on three overlapping area codes that split the city between its downtown core and its outer neighborhoods. Whether you are verifying an unknown caller, setting up a business line in the Loop, or activating a new number on the North Side, this guide breaks down every Chicago area code, the mandatory 10-digit dialing rules, major ZIP codes, and the scam calls that residents should watch for.
Chicago Area Codes at a Glance
| Detail | Information |
|---|---|
| Primary Area Code(s) | 312 / 773 |
| Overlay Area Code(s) | 872 |
| Time Zone | Central Time (CT) – CST / CDT |
| Major County | Cook County |
| Dialing Format | 10-digit dialing required |
Area Code Breakdown & District Mapping
312 – Downtown Chicago Code
Area code 312 is one of the original 1947 area codes and today covers Chicago’s central core — the Loop, downtown, and the immediately surrounding neighborhoods. A 312 number carries prestige as the historic heart of the city.
773 – Chicago Neighborhoods Code
Area code 773 was carved out of 312 in 1996 to cover Chicago’s outer neighborhoods — essentially the entire city outside the downtown core, from the North Side to the South Side.
872 – Citywide Chicago Overlay
Area code 872 is the 2009 overlay covering the full city of Chicago, layered over both the 312 and 773 regions. New Chicago lines anywhere in the city may be issued an 872 number.
Neighborhoods & Local Coverage
Chicago’s 312 code anchors the downtown core — the Loop, River North, the Gold Coast, and the Near North and Near South sides where the skyscrapers, theaters, and financial district cluster along Lake Michigan. It is the code of Chicago’s business and civic center.
The 773 and 872 codes blanket the rest of the city, covering the vast patchwork of neighborhoods that define Chicago: Lincoln Park, Lakeview, and Rogers Park on the North Side; Wicker Park and Logan Square on the Northwest Side; Pilsen and Bronzeville near the center; and Hyde Park and the sprawling South Side communities. Together the three codes keep all 77 of Chicago’s community areas connected.
Local Dialing Rules & International Format
Chicago has required 10-digit dialing since the 872 overlay launched — always dial the area code plus the 7-digit number for local calls. All three city codes (312, 773, 872) are local to one another. Suburban Cook and the collar counties use separate codes such as 847, 630, and 708.
To call Chicago from outside the United States, dial your country’s exit code, then the U.S. country code +1, followed by the 10-digit number (for example, +1 312 XXX-XXXX). From inside the U.S. and Canada, simply dial 1 before the 10-digit number for long-distance calls.
Major ZIP Codes Covered
The 312 / 773 service area spans many of Chicago’s core ZIP codes, including 60601, 60602, 60605, 60607, 60610, 60614, 60618, 60622, 60625, 60629, 60640, and 60647.
Spam & Scam Call Warnings in Chicago
Chicago residents report heavy volumes of neighbor-spoofing robocalls faking a local 312 or 773 prefix. Common scams impersonate ComEd (utility shutoff), the City of Chicago (fake parking-ticket or red-light fines), and the IRS.
| Scam Type | What to Watch For |
|---|---|
| Neighbor Spoofing | Calls that mimic a local 312 prefix to look familiar. |
| Utility / Toll Scams | Threats to shut off power or demand toll payment via gift cards. |
| IRS / Government | Robocalls claiming legal action — agencies never call to demand instant payment. |
Red flag: Any caller who pressures you to pay immediately with gift cards, wire transfers, or cryptocurrency is almost certainly running a scam. Hang up and verify through an official number.
↑ See the complete list of All US Area Codes by State for every code across the country.
Nearby & Related Illinois Cities
Frequently Asked Questions
What area code is Chicago, IL?
Chicago uses three area codes: 312 (downtown), 773 (neighborhoods), and the citywide overlay 872.
What is the difference between 312 and 773?
312 covers downtown Chicago and the central core, while 773 covers the rest of the city’s neighborhoods. The 872 overlay applies to both areas.
Do I need to dial 10 digits in Chicago?
Yes. All local calls in Chicago require 10-digit dialing (area code + number).
What time zone is Chicago in?
Chicago is in the Central Time Zone (CST/CDT), the same as the rest of Illinois.
Stay Safe & Explore More
- Verify an unknown caller in our Scam Alerts directory.
- Comparing nationwide numbers? See our Toll-Free Numbers guides.