Phone numbers in Williamsport, Maryland
Williamsport has 4 phone prefixes in area codes 240, 301.
Biggest holders: Bandwidth, Onvoy, CenturyLink / Lumen. This is the local calling area (rate center) where those prefixes were first assigned.
- Local phone company 50%
- Internet / business phone carrier 50%
Every prefix in Williamsport
Search the first six digits of a number in this list. If it's here, the number started in Williamsport with the carrier shown. If it isn't, check the Maryland page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 240-366 | Bandwidth | Internet / business phone carrier | – |
| 240-819 | Onvoy | Internet / business phone carrier | 2021 |
| 240-985 | CenturyLink / Lumen | Local phone company | 2016 |
| 301-223 | Verizon (local phone) | 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.