CHICGOZN10 — IL
Data last updated: June 25, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| T-MOBILE USA, INC. | 6529 | 34 |
| ILLINOIS BELL TEL CO | 9329 | 20 |
| NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | 14 |
| ONVOY, LLC | 224C | 6 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | 3 |