Phone numbers in Mount Airy, Maryland
Mount Airy has 8 phone prefixes in area codes 227, 240, 301.
Biggest holders: AT&T Mobility, AT&T (local phone), Core Communications. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 25%
- Local phone company 25%
- Internet / business phone carrier 50%
Every prefix in Mount Airy
Search the first six digits of a number in this list. If it's here, the number started in Mount Airy with the carrier shown. If it isn't, check the Maryland page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 227-270 | AT&T (local phone) | Local phone company | 2025 |
| 240-369 | Core Communications | Internet / business phone carrier | – |
| 240-394 | AT&T Mobility | Mobile carrier | 2004 |
| 240-732 | AT&T Mobility | Mobile carrier | 2015 |
| 240-875 | Onvoy | Internet / business phone carrier | 2019 |
| 240-924 | Bandwidth | Internet / business phone carrier | 2022 |
| 301-703 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 301-829 | 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.