Phone numbers in Dauphin Island, Alabama
Dauphin Island has 4 phone prefixes in area code 251.
Biggest holders: Onvoy, Brightspeed Of Alabama, LLC - Northern. This is the local calling area (rate center) where those prefixes were first assigned.
- Local phone company 25%
- Internet / business phone carrier 75%
Every prefix in Dauphin Island
Search the first six digits of a number in this list. If it's here, the number started in Dauphin Island with the carrier shown. If it isn't, check the Alabama page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 251-313 | Onvoy | Internet / business phone carrier | 2018 |
| 251-397 | Onvoy | Internet / business phone carrier | 2021 |
| 251-519 | Onvoy | Internet / business phone carrier | 2021 |
| 251-861 | Brightspeed Of Alabama, LLC - Northern | Local phone company | – |
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.