HOLT — MI
Data last updated: June 25, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI | 7157 | 3 |
| NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | 2 |
| MICHIGAN BELL TEL CO | 9323 | 2 |
| ACD TELECOM, INC. - MI | 3535 | 1 |
| AT&T ENTERPRISES, LLC | 516C | 1 |