Phone numbers in Hampstead, Maryland
Hampstead has 9 phone prefixes in area codes 410, 443, 667.
Biggest holders: Windstream (PAETEC), Onvoy, Verizon (local phone). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 11%
- Local phone company 11%
- Internet / business phone carrier 78%
Every prefix in Hampstead
Search the first six digits of a number in this list. If it's here, the number started in Hampstead with the carrier shown. If it isn't, check the Maryland page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 410-374 | Verizon (local phone) | Local phone company | – |
| 443-291 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 443-375 | MetroPCS (T-Mobile) | Mobile carrier | – |
| 443-507 | Teleport Communications America | Internet / business phone carrier | – |
| 443-508 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 443-639 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 667-366 | Core Communications | Internet / business phone carrier | 2018 |
| 667-477 | Onvoy | Internet / business phone carrier | 2021 |
| 667-489 | Onvoy | Internet / business phone carrier | 2024 |
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.