Phone numbers in Merrimack, New Hampshire
Merrimack has 23 phone prefixes in area code 603.
Biggest holders: UScellular, Consolidated Comm Of No. New England-nh, T-Mobile (including Sprint). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 57%
- Local phone company 26%
- Internet / business phone carrier 13%
- Paging service 4%
Every prefix in Merrimack
Search the first six digits of a number in this list. If it's here, the number started in Merrimack with the carrier shown. If it isn't, check the New Hampshire page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 603-261 | UScellular | Mobile carrier | – |
| 603-262 | Consolidated Comm Of No. New England-nh | Local phone company | – |
| 603-341 | UScellular | Mobile carrier | – |
| 603-345 | UScellular | Mobile carrier | – |
| 603-365 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 603-377 | T-Mobile (including Sprint) | Mobile carrier | – |
| 603-396 | T-Mobile (including Sprint) | Mobile carrier | – |
| 603-420 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 603-423 | Consolidated Comm Of No. New England-nh | Local phone company | – |
| 603-424 | Consolidated Comm Of No. New England-nh | Local phone company | – |
| 603-429 | Consolidated Comm Of No. New England-nh | Local phone company | – |
| 603-440 | Consolidated Comm Of No. New England-nh | Local phone company | – |
| 603-461 | UScellular | Mobile carrier | – |
| 603-493 | Bell Atlantic Mobile | Mobile carrier | – |
| 603-494 | Bell Atlantic Mobile | Mobile carrier | – |
| 603-517 | American Messaging Services | Paging service | – |
| 603-533 | UScellular | Mobile carrier | – |
| 603-582 | UScellular | Mobile carrier | – |
| 603-620 | UScellular | Mobile carrier | – |
| 603-670 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 603-683 | Consolidated Comm Of No. New England-nh | Local phone company | – |
| 603-820 | MetroPCS (T-Mobile) | Mobile carrier | 2008 |
| 603-913 | Windstream (PAETEC) | Internet / business phone carrier | – |
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.