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

DARIEN prefixes in area code 475

NANPA records 5 assigned NXX blocks to rate center DARIEN in area code 475, 1.7% of the 292 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. 4 holders hold those blocks, the largest being ONVOY, LLC - CT (2), METROPCS, INC. (1), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT (1). The earliest assignment on record here is 2014-04-30 and the most recent 2024-05-01. 5 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 203, 262, 585, 912 – overlay codes cover the same geography, so a rate center is served by all of them.

5 assigned blocks – 1.7% of 475
4 holders of record
5 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
475-259 T-Mobile METROPCS, INC. 2017-09-25 yes yes
475-264 Onvoy ONVOY, LLC - CT – yes yes
475-328 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 2014-04-30 yes yes
475-336 FRACTEL, LLC 2020-07-21 yes yes
475-368 Onvoy ONVOY, LLC - CT 2024-05-01 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
ONVOY, LLC - CT Onvoy 2 40%
METROPCS, INC. T-Mobile 1 20%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT Verizon 1 20%
FRACTEL, LLC – 1 20%

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 DARIEN in area code 475?

5 blocks: 259, 264, 328, 336, 368. The table above gives the holder of each.

Which carriers have numbers in DARIEN?

ONVOY, LLC - CT (2 blocks), METROPCS, INC. (1 block), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT (1 block), FRACTEL, 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 DARIEN 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 475

All 292 prefixes in 475