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

WHITLOW prefixes in area code 520

NANPA records 7 assigned NXX blocks to rate center WHITLOW in area code 520, 1.0% of the 699 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 - AZ (3), QWEST CORPORATION (2), BANDWIDTH.COM CLEC, LLC - AZ (1). The earliest assignment on record here is 2012-05-08 and the most recent 2022-03-01. 7 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

7 assigned blocks – 1% of 520
4 holders of record
7 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
520-231 Bandwidth BANDWIDTH.COM CLEC, LLC - AZ – yes yes
520-277 Onvoy ONVOY, LLC - AZ 2012-05-08 yes yes
520-438 Onvoy ONVOY, LLC - AZ 2019-10-03 yes yes
520-463 Lumen QWEST CORPORATION – yes yes
520-583 IP HORIZON LLC 2021-09-03 yes yes
520-650 Onvoy ONVOY, LLC - AZ 2020-10-29 yes yes
520-652 Lumen QWEST CORPORATION 2022-03-01 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 - AZ Onvoy 3 42.9%
QWEST CORPORATION Lumen 2 28.6%
BANDWIDTH.COM CLEC, LLC - AZ Bandwidth 1 14.3%
IP HORIZON LLC – 1 14.3%

Frequently asked

Which prefixes belong to WHITLOW in area code 520?

7 blocks: 231, 277, 438, 463, 583, 650, 652. The table above gives the holder of each.

Which carriers have numbers in WHITLOW?

ONVOY, LLC - AZ (3 blocks), QWEST CORPORATION (2 blocks), BANDWIDTH.COM CLEC, LLC - AZ (1 block), IP HORIZON 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 WHITLOW 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 520

All 699 prefixes in 520