JOLIET — IL
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | 25 |
| T-MOBILE USA, INC. | 6529 | 19 |
| ILLINOIS BELL TEL CO | 9329 | 15 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL | 6333 | 8 |
| METROPCS, INC. | 5562 | 5 |