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

WINDOWROCK prefixes in area code 928

NANPA records 6 assigned NXX blocks to rate center WINDOWROCK in area code 928, 0.9% of the 637 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 NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM (3), SMITH BAGLEY INC. DBA CELLULAR ONE OF NE ARIZONA (1), LEVEL 3 COMMUNICATIONS, LLC - AZ (1). The earliest assignment on record here is 2011-02-03 and the most recent 2021-07-15. 4 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

6 assigned blocks – 0.9% of 928
4 holders of record
4 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
928-309 SMITH BAGLEY INC. DBA CELLULAR ONE OF NE ARIZONA – no yes
928-357 Lumen LEVEL 3 COMMUNICATIONS, LLC - AZ 2019-10-31 yes yes
928-407 Telnyx TELNYX LLC 2021-07-15 yes yes
928-810 Frontier NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM – yes yes
928-815 Frontier NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM 2011-02-03 yes yes
928-871 Frontier NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM – no 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
NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM Frontier 3 50%
SMITH BAGLEY INC. DBA CELLULAR ONE OF NE ARIZONA – 1 16.7%
LEVEL 3 COMMUNICATIONS, LLC - AZ Lumen 1 16.7%
TELNYX LLC Telnyx 1 16.7%

Frequently asked

Which prefixes belong to WINDOWROCK in area code 928?

6 blocks: 309, 357, 407, 810, 815, 871. The table above gives the holder of each.

Which carriers have numbers in WINDOWROCK?

NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM (3 blocks), SMITH BAGLEY INC. DBA CELLULAR ONE OF NE ARIZONA (1 block), LEVEL 3 COMMUNICATIONS, LLC - AZ (1 block), TELNYX 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 WINDOWROCK 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 928

All 637 prefixes in 928