Phone numbers in Winthrop, Massachusetts
Winthrop has 11 phone prefixes in area codes 617, 857.
Biggest holders: Onvoy, Verizon (local phone), Comcast. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 9%
- Local phone company 18%
- Internet / business phone carrier 64%
- Phone company 9%
Every prefix in Winthrop
Search the first six digits of a number in this list. If it's here, the number started in Winthrop with the carrier shown. If it isn't, check the Massachusetts page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 617-207 | Comcast | Internet / business phone carrier | – |
| 617-329 | Rcn Telecom Services | Phone company | – |
| 617-539 | Verizon (local phone) | Local phone company | – |
| 617-841 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 617-846 | Verizon (local phone) | Local phone company | – |
| 857-201 | MetroPCS (T-Mobile) | Mobile carrier | 2002 |
| 857-336 | Onvoy | Internet / business phone carrier | 2016 |
| 857-349 | Bandwidth | Internet / business phone carrier | 2018 |
| 857-597 | Onvoy | Internet / business phone carrier | 2021 |
| 857-816 | MCImetro (Verizon Business) | Internet / business phone carrier | 2001 |
| 857-833 | 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.