To faciltiate users, the United States of America is divided into regions known as Area Codes, corresponding to particular geographic telephone dialing areas.
An area code denotes the regional location of a phone number within the United States.
The Area Code table below shows an area codes each.
Area Code 312 listing, by city
@The cities listed with each area code are the major cities for that area code;
| City / State | Area code | Zip Code | County | Iso | |
|---|---|---|---|---|---|
| Chicago (Illinois) | 312 | 60290 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60610 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60642 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60663 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60664 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60666 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60668 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60669 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60670 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60673 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60674 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60675 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60677 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60678 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60679 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60680 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60681 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60682 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60684 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60685 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60686 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60687 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60688 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60689 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60690 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60691 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60693 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60694 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60695 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60696 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60697 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60603 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60604 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60605 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60606 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60609 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60638 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60654 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60661 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60605 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60603 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60699 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60632 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60604 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60638 | Cook | US-IL | |
| Chicago (Illinois) | 312 | 60661 | Cook | US-IL | |
| Hinsdale (Illinois) | 312 | 60522 | Dupage | US-IL |