NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

TAMWORTH prefixes in area code 603

NANPA records 3 assigned NXX blocks to rate center TAMWORTH in area code 603, 0.4% of the 752 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 3 holders hold those blocks, the largest being CONSOLIDATED COMM OF NO. NEW ENGLAND-NH (1), LEVEL 3 COMMUNICATIONS, LLC - NH (1), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH (1). 3 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

3 assigned blocks – 0.4% of 603
3 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
603-323 Consolidated CONSOLIDATED COMM OF NO. NEW ENGLAND-NH – yes yes
603-725 Lumen LEVEL 3 COMMUNICATIONS, LLC - NH – yes yes
603-861 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH – yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
CONSOLIDATED COMM OF NO. NEW ENGLAND-NH Consolidated 1 33.3%
LEVEL 3 COMMUNICATIONS, LLC - NH Lumen 1 33.3%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH Verizon 1 33.3%

Frequently asked

Which prefixes belong to TAMWORTH in area code 603?

3 blocks: 323, 725, 861. The table above gives the holder of each.

Which carriers have numbers in TAMWORTH?

CONSOLIDATED COMM OF NO. NEW ENGLAND-NH (1 block), LEVEL 3 COMMUNICATIONS, LLC - NH (1 block), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is TAMWORTH a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 603

All 752 prefixes in 603