Phone numbers in Charlestn, Massachusetts
Charlestn has 23 phone prefixes in area codes 617, 857.
Biggest holders: MCImetro (Verizon Business), T-Mobile (including Sprint), Onvoy. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 22%
- Local phone company 13%
- Internet / business phone carrier 61%
- Phone company 4%
Every prefix in Charlestn
Search the first six digits of a number in this list. If it's here, the number started in Charlestn with the carrier shown. If it isn't, check the Massachusetts page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 617-241 | Verizon (local phone) | Local phone company | – |
| 617-242 | Verizon (local phone) | Local phone company | – |
| 617-286 | Windstream (PAETEC) | Internet / business phone carrier | 2001 |
| 617-337 | Rcn Telecom Services | Phone company | – |
| 617-380 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 617-398 | Bandwidth | Internet / business phone carrier | – |
| 617-518 | Onvoy | Internet / business phone carrier | 2021 |
| 617-580 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 617-669 | T-Mobile (including Sprint) | Mobile carrier | – |
| 617-681 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 617-712 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 617-886 | Verizon (local phone) | Local phone company | – |
| 617-952 | MCImetro (Verizon Business) | Internet / business phone carrier | 2001 |
| 857-389 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 857-391 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 857-410 | Bandwidth | Internet / business phone carrier | 2016 |
| 857-452 | T-Mobile (including Sprint) | Mobile carrier | – |
| 857-468 | TON80 Communications | Internet / business phone carrier | 2022 |
| 857-497 | T-Mobile (including Sprint) | Mobile carrier | 2023 |
| 857-577 | Onvoy | Internet / business phone carrier | 2016 |
| 857-588 | MCImetro (Verizon Business) | Internet / business phone carrier | 2001 |
| 857-837 | Onvoy | Internet / business phone carrier | 2020 |
| 857-971 | Onvoy | Internet / business phone carrier | 2016 |
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.