| General Information | |
|---|---|
| Country | United States |
| State/Province | Illinois |
| Major City | Rockford |
| Time Zone | Central (UTC-06:00) |
| Current Local Time | 20:01 |
| Prefix | County | Primary City |
|---|---|---|
| 815-200 | La Salle | La Salle |
| 815-201 | Winnebago | Rockford |
| 815-202 | La Salle | Oglesby |
| 815-203 | Will | Joliet |
| 815-204 | Mchenry | Crystal Lake |
| 815-205 | Cook | Brookfield |
| 815-206 | Mchenry | Woodstock |
| 815-207 | Will | Joliet |
| 815-208 | Whiteside | Fulton |
| 815-209 | Winnebago | Rockford |
| 815-210 | Will | Joliet |
| 815-212 | Will | Joliet |
| 815-213 | Whiteside | Sterling |
| 815-214 | Kankakee | Kankakee |
| 815-215 | Will | New Lenox |
| 815-216 | Kankakee | Bradley |
| 815-217 | Dekalb | Dekalb |
| 815-218 | Winnebago | Rockford |
| 815-219 | Mchenry | Crystal Lake |
| 815-220 | La Salle | La Salle |
| 815-221 | Will | Romeoville |
| 815-222 | Winnebago | Rockford |
| 815-223 | La Salle | La Salle |
| 815-224 | La Salle | La Salle |
| 815-225 | Carroll | Milledgeville |
| 815-226 | Winnebago | Rockford |
| 815-227 | Winnebago | Rockford |
| 815-228 | La Salle | Oglesby |
| 815-229 | Winnebago | Rockford |
| 815-230 | Will | Plainfield |
| 815-231 | Winnebago | Rockford |
| 815-232 | Stephenson | Freeport |
| 815-233 | Stephenson | Freeport |
| 815-234 | Ogle | Byron |
| 815-235 | Stephenson | Freeport |
| 815-236 | Mchenry | Woodstock |
| 815-237 | Grundy | Gardner |
| 815-238 | Stephenson | Freeport |
| 815-239 | Winnebago | Pecatonica |
| 815-240 | Winnebago | Rockford |
| 815-241 | Cook | Glenview |
| 815-242 | Winnebago | Rockford |
| 815-243 | Winnebago | Rockford |
| 815-244 | Carroll | Mount Carroll |
| 815-245 | Mchenry | Woodstock |
| 815-246 | La Salle | Earlville |
| 815-247 | Stephenson | German Valley |
| 815-248 | Winnebago | Durand |
| 815-249 | La Salle | Grand Ridge |
| 815-250 | La Salle | La Salle |