| 331 Area Code Basic Information | |
|---|---|
| Area Code | 331 |
| Location | IL |
| Country | US |
| In Service Date | 2007-10-07 |
| Service Length | 18 years |
| Overlay Area Code? | Yes |
| Overlay Area Codes | 331 630 |
| Parent Area Code | 630 |
| Time Zone | C |
| Map | 362 |
| Area code in jeopardy? | No |
The following section explains how to dial outbound numbers from this area code.