| 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 |
|---|---|---|---|
| 815-429 | Sheldon | Iroquois | Landline |
| 815-786 | Sandwich | Dekalb | Landline |
| 815-866 | Princeton | Bureau | Wireless |
| 815-374 | Dwight | Livingston | Landline |
| 815-751 | Dekalb | Dekalb | Wireless |
| 815-242 | Rockford | Winnebago | Wireless |
| 815-321 | Woodstock | Mchenry | Landline |
| 815-809 | Lena | Stephenson | Landline |
| 815-308 | Woodstock | Mchenry | Landline |
| 815-675 | Spring Grove | Mchenry | Landline |
| 815-636 | Loves Park | Winnebago | Landline |
| 815-384 | Rochelle | Ogle | Landline |
| 815-436 | Plainfield | Will | Landline |
| 815-634 | Coal City | Grundy | Landline |
| 815-263 | Bradley | Kankakee | Wireless |
| 815-245 | Woodstock | Mchenry | Wireless |
| 815-826 | Somonauk | Dekalb | Wireless |
| 815-917 | Rochelle | Ogle | Landline |
| 815-203 | Joliet | Will | Wireless |
| 815-413 | Morris | Grundy | Landline |