Phone numbers in Chelsea, Massachusetts
Chelsea has 16 phone prefixes in area codes 617, 857.
Biggest holders: Verizon (local phone), MetroPCS (T-Mobile), Windstream (PAETEC). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 12%
- Local phone company 38%
- Internet / business phone carrier 50%
Every prefix in Chelsea
Search the first six digits of a number in this list. If it's here, the number started in Chelsea with the carrier shown. If it isn't, check the Massachusetts page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 617-270 | MetroPCS (T-Mobile) | Mobile carrier | 2001 |
| 617-336 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 617-370 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 617-409 | Windstream (PAETEC) | Internet / business phone carrier | 2001 |
| 617-461 | MetroPCS (T-Mobile) | Mobile carrier | – |
| 617-466 | Comcast | Internet / business phone carrier | – |
| 617-660 | Verizon (local phone) | Local phone company | – |
| 617-819 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 617-884 | Verizon (local phone) | Local phone company | – |
| 617-887 | Verizon (local phone) | Local phone company | – |
| 617-889 | Verizon (local phone) | Local phone company | – |
| 617-958 | Onvoy | Internet / business phone carrier | – |
| 857-323 | Verizon (local phone) | Local phone company | 2013 |
| 857-386 | Verizon (local phone) | Local phone company | 2016 |
| 857-475 | Onvoy | Internet / business phone carrier | 2021 |
| 857-776 | Level 3 (Lumen) | Internet / business phone carrier | 2001 |
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.