| 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 |
|---|---|---|---|
| 815-952 | Lanark | Carroll | Landline |
| 815-247 | German Valley | Stephenson | Landline |
| 815-835 | Dixon | Lee | Landline |
| 815-662 | Momence | Kankakee | Landline |
| 815-431 | Ottawa | La Salle | Landline |
| 815-629 | Rockton | Winnebago | Landline |
| 815-581 | Spring Grove | Mchenry | Landline |
| 815-462 | New Lenox | Will | Landline |
| 815-893 | Crystal Lake | Mchenry | Landline |
| 815-808 | Winslow | Stephenson | Landline |
| 815-205 | Brookfield | Cook | Wireless |
| 815-391 | Rockford | Winnebago | Landline |
| 815-472 | Momence | Kankakee | Landline |
| 815-502 | Woodstock | Mchenry | Landline |
| 815-241 | Glenview | Cook | Wireless |
| 815-753 | Dekalb | Dekalb | Landline |
| 815-759 | Mchenry | Mchenry | Landline |
| 815-600 | Joliet | Will | Landline |
| 815-319 | Rockford | Winnebago | Wireless |
| 815-266 | Freeport | Stephenson | Landline |