OTTAWA — IL
Data last updated: June 25, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | 3 |
| ILLINOIS BELL TEL CO | 9329 | 3 |
| TELEPORT COMMUNICATIONS AMERICA, LLC - IL | 7136 | 2 |
| FIRST COMMUNICATIONS, LLC | 460K | 1 |
| MCC TELEPHONY LLC | 593K | 1 |