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

WILLIAMSTN prefixes in area code 304

NANPA records 3 assigned NXX blocks to rate center WILLIAMSTN in area code 304, 0.4% of the 785 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 T-MOBILE USA, INC. (1), FRONTIER WEST VIRGINIA INC. (1), CSC VOICE, LLC (1). 3 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots. The same rate center name also appears in area codes 252, 315, 413, 517 – overlay codes cover the same geography, so a rate center is served by all of them.

3 assigned blocks – 0.4% of 304
3 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
304-200 T-Mobile T-MOBILE USA, INC. – yes yes
304-375 Frontier FRONTIER WEST VIRGINIA INC. – yes yes
304-850 CSC VOICE, LLC – 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
T-MOBILE USA, INC. T-Mobile 1 33.3%
FRONTIER WEST VIRGINIA INC. Frontier 1 33.3%
CSC VOICE, LLC – 1 33.3%

Same rate center in other codes

Overlay codes cover the same geography, so one rate center is served by all of them.

Frequently asked

Which prefixes belong to WILLIAMSTN in area code 304?

3 blocks: 200, 375, 850. The table above gives the holder of each.

Which carriers have numbers in WILLIAMSTN?

T-MOBILE USA, INC. (1 block), FRONTIER WEST VIRGINIA INC. (1 block), CSC VOICE, LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is WILLIAMSTN 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 304

All 785 prefixes in 304