Phone numbers in Middletown, Maryland
Middletown has 6 phone prefixes in area codes 227, 240, 301.
Biggest holders: Onvoy, T-Mobile (including Sprint), TON80 Communications. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 33%
- Local phone company 17%
- Internet / business phone carrier 50%
Every prefix in Middletown
Search the first six digits of a number in this list. If it's here, the number started in Middletown with the carrier shown. If it isn't, check the Maryland page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 227-242 | Onvoy | Internet / business phone carrier | 2024 |
| 240-490 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 240-663 | T-Mobile (including Sprint) | Mobile carrier | 2019 |
| 240-870 | Onvoy | Internet / business phone carrier | 2016 |
| 240-934 | TON80 Communications | Internet / business phone carrier | 2021 |
| 301-371 | 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.