Phone numbers in Holt, Michigan
Holt has 13 phone prefixes in area code 517.
Biggest holders: MCImetro (Verizon Business), AT&T Mobility, AT&T (local phone). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 15%
- Local phone company 15%
- Internet / business phone carrier 54%
- Phone company 15%
Every prefix in Holt
Search the first six digits of a number in this list. If it's here, the number started in Holt with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 517-209 | Bandwidth | Internet / business phone carrier | 2009 |
| 517-221 | AT&T Mobility | Mobile carrier | 2016 |
| 517-268 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 517-477 | AT&T Mobility | Mobile carrier | 2004 |
| 517-694 | AT&T (local phone) | Local phone company | – |
| 517-699 | AT&T (local phone) | Local phone company | – |
| 517-709 | MCImetro (Verizon Business) | Internet / business phone carrier | 2006 |
| 517-742 | AT&T Enterprises | Phone company | 2008 |
| 517-758 | Fractel | Internet / business phone carrier | 2019 |
| 517-777 | Onvoy | Internet / business phone carrier | 2015 |
| 517-876 | MCImetro (Verizon Business) | Internet / business phone carrier | 2005 |
| 517-889 | Windstream (PAETEC) | Internet / business phone carrier | 2006 |
| 517-906 | Acd Telecom | Phone company | 2002 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.