Illinois area codes: full list with cities and how to dial
Illinois has roughly 12.5 million residents, and its phone numbers are organized into 17 area codes under the North American Numbering Plan. Illinois is served by 17 active geographic area codes, anchored by 312 in the Chicago area. Every Illinois numbering plan area is now an overlay complex, requiring ten-digit dialing statewide. Every Illinois number is dialed as +1, then the three-digit area code, then a seven-digit local number. With Phonecall you can call any Illinois landline or mobile straight from your browser. There is no app to install, no SIM, and no subscription. You see the per-minute rate before you dial, billing is by the second, and your first call is free.
Call Illinois from your browserAll Illinois area codes
17 active geographic area codes in service across Illinois.
| Area code | Primary cities and region | Example number |
|---|---|---|
| 312 | Central Chicago (downtown and the Loop) | +1 (312) 555-0100 |
| 773 | City of Chicago outside the Loop (overlay of 312/872) | +1 (773) 555-0100 |
| 872 | Chicago citywide overlay of 312/773 | +1 (872) 555-0100 |
| 847 | North and northwest Chicago suburbs | +1 (847) 555-0100 |
| 224 | North and northwest suburbs (overlay of 847) | +1 (224) 555-0100 |
| 630 | Western suburbs (DuPage and Kane counties) | +1 (630) 555-0100 |
| 331 | Western suburbs (overlay of 630) | +1 (331) 555-0100 |
| 708 | South and west Chicago suburbs | +1 (708) 555-0100 |
| 464 | South and west suburbs (overlay of 708) | +1 (464) 555-0100 |
| 815 | Northern Illinois (Rockford, Joliet, DeKalb) | +1 (815) 555-0100 |
| 779 | Northern Illinois (overlay of 815) | +1 (779) 555-0100 |
| 217 | Central Illinois (Springfield, Champaign, Decatur) | +1 (217) 555-0100 |
| 447 | Central Illinois (overlay of 217) | +1 (447) 555-0100 |
| 309 | Central-western Illinois (Peoria, Bloomington, Moline) | +1 (309) 555-0100 |
| 861 | Central-western Illinois (overlay of 309) | +1 (861) 555-0100 |
| 618 | Southern Illinois (Belleville, Carbondale, East St. Louis) | +1 (618) 555-0100 |
| 730 | Southern Illinois (overlay of 618) | +1 (730) 555-0100 |
Example numbers use the reserved 555-0100 range and are for illustration only.
How to call Illinois from abroad
Every Illinois phone number is part of the +1 North American calling zone. To reach one from outside the United States, dial three parts in order:
- 1. Your exit code, then +1 — the US country code.
- 2. The three-digit area code — for example 312 for the Chicago area.
- 3. The seven-digit local number.
Example, full international format:
+1 (312) 555-0100
With Phonecall you skip the exit codes entirely. Enter the number in international format and we connect the call from your browser, billed by the second from $0.03/min, with no SIM, no app, and no monthly fee.
Why Illinois has multiple area codes
Every Illinois numbering plan area is now an overlay complex, requiring ten-digit dialing statewide.
When a region runs low on available numbers, the phone system adds capacity in one of two ways. A split divides the old region geographically and gives part of it a brand-new area code. An overlay keeps the existing code and layers a second one on top of the same area, which is why a single city can have several area codes and why ten-digit dialing becomes the norm. Either way, the number you dial always stays the same length: +1, the area code, then seven digits.
17
active area codes
~12.5 million
residents (approx.)
Chicago
largest city
Calling Illinois with Phonecall
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Illinois area codes: frequently asked questions
What is the main area code for Chicago?
Chicago, the largest city in Illinois, is primarily served by area code 312 (Central Chicago (downtown and the Loop)). Illinois has 17 area codes in total, listed in full above.
How do I dial a Illinois number from another country?
Dial your international exit code, then +1 (the US country code), then the three-digit Illinois area code, then the seven-digit local number. With Phonecall you just enter the number in international format and we connect the call from your browser, from $0.03/min.
How many area codes does Illinois have?
Illinois currently has 17 active geographic area codes in service. Every Illinois numbering plan area is now an overlay complex, requiring ten-digit dialing statewide.