| General Information about Area Code 815 | |
|---|---|
| Country | United States |
| State / Province / Territory | Illinois |
| Major City | Rockford |
| Time Zone | Central (UTC-06:00) |
| Prefix | Primary City | County | Phone Type |
|---|---|---|---|
| 815-654 | Loves Park | Winnebago | Landline |
| 815-724 | Joliet | Will | Landline |
| 815-931 | Joliet | Will | Wireless |
| 815-764 | Dekalb | Dekalb | Wireless |
| 815-907 | Manteno | Kankakee | Landline |
| 815-212 | Joliet | Will | Landline |
| 815-597 | Marengo | Mchenry | Landline |
| 815-630 | Joliet | Will | Wireless |
| 815-946 | Polo | Ogle | Landline |
| 815-566 | Belvidere | Boone | Landline |
| 815-795 | Marseilles | La Salle | Landline |
| 815-937 | Kankakee | Kankakee | Landline |
| 815-696 | Roscoe | Winnebago | Landline |
| 815-857 | Amboy | Lee | Landline |
| 815-322 | Mchenry | Mchenry | Landline |
| 815-345 | Woodstock | Mchenry | Landline |
| 815-428 | Martinton | Iroquois | Landline |
| 815-743 | Graymont | Livingston | Landline |
| 815-480 | Rockford | Winnebago | Wireless |
| 815-745 | Warren | Jo Daviess | Landline |