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

CEDAR HILL prefixes in area code 972

NANPA records 7 assigned NXX blocks to rate center CEDAR HILL in area code 972, 0.9% 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. 4 holders hold those blocks, the largest being SOUTHWESTERN BELL (4), ONVOY, LLC - TX (1), LEVEL 3 OF TELECOM OF TEXAS, LLC - TX (1). The earliest assignment on record here is 2003-03-04 and the most recent 2003-03-04. 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 214, 469, 636, 945 – overlay codes cover the same geography, so a rate center is served by all of them.

7 assigned blocks – 0.9% of 972
4 holders of record
5 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
972-291 AT&T SOUTHWESTERN BELL – no yes
972-293 AT&T SOUTHWESTERN BELL – no yes
972-299 AT&T SOUTHWESTERN BELL – yes yes
972-460 Onvoy ONVOY, LLC - TX – yes yes
972-637 Lumen LEVEL 3 OF TELECOM OF TEXAS, LLC - TX – yes yes
972-765 AT&T NEW CINGULAR WIRELESS PCS, LLC - IL 2003-03-04 yes yes
972-779 AT&T SOUTHWESTERN BELL – 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
SOUTHWESTERN BELL AT&T 4 57.1%
ONVOY, LLC - TX Onvoy 1 14.3%
LEVEL 3 OF TELECOM OF TEXAS, LLC - TX Lumen 1 14.3%
NEW CINGULAR WIRELESS PCS, LLC - IL AT&T 1 14.3%

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 CEDAR HILL in area code 972?

7 blocks: 291, 293, 299, 460, 637, 765, 779. The table above gives the holder of each.

Which carriers have numbers in CEDAR HILL?

SOUTHWESTERN BELL (4 blocks), ONVOY, LLC - TX (1 block), LEVEL 3 OF TELECOM OF TEXAS, LLC - TX (1 block), NEW CINGULAR WIRELESS PCS, LLC - IL (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is CEDAR HILL 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 972

All 785 prefixes in 972