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

REDONDO prefixes in area code 310

NANPA records 44 assigned NXX blocks to rate center REDONDO in area code 310, 5.6% of the 786 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. 9 holders hold those blocks, the largest being FRONTIER CALIFORNIA INC. (33), T-MOBILE USA, INC. (3), U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS (2). The earliest assignment on record here is 2002-06-14 and the most recent 2012-10-04. 20 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 code 424 – overlay codes cover the same geography, so a rate center is served by all of them.

44 assigned blocks – 5.6% of 310
9 holders of record
20 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
310-214 Frontier FRONTIER CALIFORNIA INC. – no yes
310-265 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-303 AT&T PACIFIC BELL (COMPETITIVE) – yes yes
310-316 Frontier FRONTIER CALIFORNIA INC. – no yes
310-318 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-370 Frontier FRONTIER CALIFORNIA INC. – no yes
310-371 Frontier FRONTIER CALIFORNIA INC. – no yes
310-372 Frontier FRONTIER CALIFORNIA INC. – no yes
310-373 Frontier FRONTIER CALIFORNIA INC. – no yes
310-374 Frontier FRONTIER CALIFORNIA INC. – no yes
310-375 Frontier FRONTIER CALIFORNIA INC. – no yes
310-376 Frontier FRONTIER CALIFORNIA INC. – no yes
310-377 Frontier FRONTIER CALIFORNIA INC. – no yes
310-378 Frontier FRONTIER CALIFORNIA INC. – no yes
310-379 Frontier FRONTIER CALIFORNIA INC. – no yes
310-406 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-421 T-Mobile T-MOBILE USA, INC. – yes yes
310-465 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-504 Peerless PEERLESS NETWORK OF CALIFORNIA, LLC - CA 2012-10-04 yes yes
310-540 Frontier FRONTIER CALIFORNIA INC. – no yes
310-541 Frontier FRONTIER CALIFORNIA INC. – no yes
310-542 Frontier FRONTIER CALIFORNIA INC. – no yes
310-543 Frontier FRONTIER CALIFORNIA INC. – no yes
310-544 Frontier FRONTIER CALIFORNIA INC. – no yes
310-545 Frontier FRONTIER CALIFORNIA INC. – no yes
310-546 Frontier FRONTIER CALIFORNIA INC. – no yes
310-683 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - CA – yes yes
310-697 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
310-698 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS – yes yes
310-750 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA – yes yes
310-791 Frontier FRONTIER CALIFORNIA INC. – no yes
310-792 Frontier FRONTIER CALIFORNIA INC. – no yes
310-793 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-796 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-798 Frontier FRONTIER CALIFORNIA INC. – no yes
310-802 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-863 T-Mobile T-MOBILE USA, INC. – yes yes
310-870 Bandwidth BANDWIDTH.COM CLEC, LLC - CA 2012-05-22 yes yes
310-896 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS – yes yes
310-921 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-937 Frontier FRONTIER CALIFORNIA INC. – no yes
310-939 Frontier FRONTIER CALIFORNIA INC. – no yes
310-944 Frontier FRONTIER CALIFORNIA INC. – yes yes
310-947 T-Mobile T-MOBILE USA, INC. 2002-06-14 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
FRONTIER CALIFORNIA INC. Frontier 33 75%
T-MOBILE USA, INC. T-Mobile 3 6.8%
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS TPx 2 4.5%
PACIFIC BELL (COMPETITIVE) AT&T 1 2.3%
PEERLESS NETWORK OF CALIFORNIA, LLC - CA Peerless 1 2.3%
TELEPORT COMMUNICATIONS AMERICA, LLC - CA AT&T 1 2.3%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC Verizon 1 2.3%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA Verizon 1 2.3%
BANDWIDTH.COM CLEC, LLC - CA Bandwidth 1 2.3%

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 REDONDO in area code 310?

44 blocks: 214, 265, 303, 316, 318, 370, 371, 372, 373, 374, 375, 376 and 32 more, all listed in the table above.

Which carriers have numbers in REDONDO?

FRONTIER CALIFORNIA INC. (33 blocks), T-MOBILE USA, INC. (3 blocks), U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS (2 blocks), PACIFIC BELL (COMPETITIVE) (1 block), PEERLESS NETWORK OF CALIFORNIA, LLC - CA (1 block), TELEPORT COMMUNICATIONS AMERICA, LLC - CA (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is REDONDO 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 310

All 786 prefixes in 310