| 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 |
|---|---|---|---|
| 815-772 | Morrison | Whiteside | Landline |
| 815-393 | Monroe Center | Ogle | Landline |
| 815-358 | Cornell | Livingston | Landline |
| 815-213 | Sterling | Whiteside | Wireless |
| 815-237 | Gardner | Grundy | Landline |
| 815-822 | Ancona | Livingston | Wireless |
| 815-760 | Tiskilwa | Bureau | Wireless |
| 815-642 | Minooka | Grundy | Landline |
| 815-532 | Mazon | Grundy | Wireless |
| 815-816 | Freeport | Stephenson | Landline |
| 815-443 | Pearl City | Stephenson | Landline |
| 815-605 | Grant Park | Kankakee | Landline |
| 815-546 | Joliet | Will | Wireless |
| 815-649 | Gardner | Grundy | Landline |
| 815-412 | Frankfort | Will | Landline |
| 815-691 | Utica | La Salle | Landline |
| 815-471 | Watseka | Iroquois | Wireless |
| 815-847 | Rockford | Winnebago | Landline |
| 815-536 | Brookfield | Cook | Wireless |
| 815-293 | Lockport | Will | Landline |