CHICGOZN03 — IL
Data last updated: October 30, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| T-MOBILE USA, INC. | 6529 | 86 |
| NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | 40 |
| ILLINOIS BELL TEL CO | 9329 | 33 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL | 6333 | 13 |
| ONVOY, LLC | 224C | 7 |