ALTO — MI
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| CSC WIRELESS, LLC | 425J | 1 |
| TWILIO INTERNATIONAL, INC. | 506J | 1 |
| ONVOY, LLCV - MI | 543C | 1 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI | 7157 | 1 |
| MICHIGAN BELL TEL CO | 9323 | 1 |