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

COLFAX prefixes in area code 530

NANPA records 6 assigned NXX blocks to rate center COLFAX in area code 530, 0.8% of the 782 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. 5 holders hold those blocks, the largest being ONVOY, LLC - CA (2), FRONTIER CALIFORNIA INC. (1), TELEPORT COMMUNICATIONS AMERICA, LLC - CA (1). The earliest assignment on record here is 2020-06-01 and the most recent 2021-11-12. 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 309, 318, 509, 515 – overlay codes cover the same geography, so a rate center is served by all of them.

6 assigned blocks – 0.8% of 530
5 holders of record
5 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
530-323 Onvoy ONVOY, LLC - CA – no yes
530-346 Frontier FRONTIER CALIFORNIA INC. – yes yes
530-349 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - CA – yes yes
530-512 Onvoy ONVOY, LLC - CA – yes yes
530-819 Bandwidth BANDWIDTH.COM CLEC, LLC - CA 2021-11-12 yes yes
530-866 FRACTEL, LLC 2020-06-01 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 - CA Onvoy 2 33.3%
FRONTIER CALIFORNIA INC. Frontier 1 16.7%
TELEPORT COMMUNICATIONS AMERICA, LLC - CA AT&T 1 16.7%
BANDWIDTH.COM CLEC, LLC - CA Bandwidth 1 16.7%
FRACTEL, LLC – 1 16.7%

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 COLFAX in area code 530?

6 blocks: 323, 346, 349, 512, 819, 866. The table above gives the holder of each.

Which carriers have numbers in COLFAX?

ONVOY, LLC - CA (2 blocks), FRONTIER CALIFORNIA INC. (1 block), TELEPORT COMMUNICATIONS AMERICA, LLC - CA (1 block), BANDWIDTH.COM CLEC, LLC - CA (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 COLFAX 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 530

All 782 prefixes in 530