| 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 |
|---|---|---|---|
| 815-576 | Polo | Ogle | Landline |
| 815-279 | Bradley | Kankakee | Wireless |
| 815-891 | Winnebago | Winnebago | Landline |
| 815-610 | Cornell | Livingston | Landline |
| 815-755 | Dekalb | Dekalb | Wireless |
| 815-626 | Sterling | Whiteside | Landline |
| 815-450 | Momence | Kankakee | Wireless |
| 815-643 | Princeton | Bureau | Landline |
| 815-336 | Chadwick | Carroll | Landline |
| 815-701 | Woodstock | Mchenry | Landline |
| 815-838 | Romeoville | Will | Landline |
| 815-375 | Dekalb | Dekalb | Wireless |
| 815-258 | Joliet | Will | Wireless |
| 815-235 | Freeport | Stephenson | Landline |
| 815-690 | Joliet | Will | Wireless |
| 815-565 | Morrison | Whiteside | Landline |
| 815-974 | Mineral | Bureau | Landline |
| 815-915 | Coal City | Grundy | Landline |
| 815-254 | Plainfield | Will | Landline |
| 815-782 | Plainfield | Will | Landline |