| General Information about Area Code 312 | |
|---|---|
| Country | United States |
| State / Province / Territory | Illinois |
| Major City | Chicago |
| Time Zone | Central (UTC-06:00) |
| Prefix | Primary City | County | Phone Type |
|---|---|---|---|
| 312-530 | Chicago | Cook | Wireless |
| 312-570 | Chicago | Cook | Landline |
| 312-837 | - | - | - |
| 312-300 | Chicago | Cook | Landline |
| 312-472 | Chicago | Cook | Landline |
| 312-362 | Chicago | Cook | Landline |
| 312-521 | Chicago | Cook | Landline |
| 312-998 | Chicago | Cook | Landline |
| 312-415 | Chicago | Cook | Wireless |
| 312-295 | Brookfield | Cook | Wireless |
| 312-605 | Chicago | Cook | Landline |
| 312-232 | Chicago | Cook | Wireless |
| 312-458 | Chicago | Cook | Landline |
| 312-374 | Chicago | Cook | Landline |
| 312-645 | Chicago | Cook | Landline |
| 312-931 | Chicago | Cook | Landline |
| 312-417 | Chicago | Cook | Wireless |
| 312-419 | Chicago | Cook | Landline |
| 312-845 | Chicago | Cook | Landline |
| 312-709 | Chicago | Cook | Wireless |