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

OKLD ALMD prefixes in area code 510

NANPA records 42 assigned NXX blocks to rate center OKLD ALMD in area code 510, 5.4% 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. 12 holders hold those blocks, the largest being PACIFIC BELL (12), METROPCS, INC. (5), LEVEL 3 COMMUNICATIONS, LLC - CA (5). The earliest assignment on record here is 2011-09-15 and the most recent 2024-05-31. 33 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 341 – overlay codes cover the same geography, so a rate center is served by all of them.

42 assigned blocks – 5.4% of 510
12 holders of record
33 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
510-205 T-Mobile METROPCS, INC. – yes yes
510-214 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA – yes yes
510-217 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - CA – yes yes
510-227 Lumen LEVEL 3 TELECOM OF CALIFORNIA, LP - CA – yes yes
510-239 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS – yes yes
510-254 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA 2011-09-15 yes yes
510-263 AT&T PACIFIC BELL – yes yes
510-306 T-Mobile METROPCS, INC. – yes yes
510-337 AT&T PACIFIC BELL – yes yes
510-355 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
510-373 Onvoy ONVOY, LLC - CA – yes yes
510-473 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
510-519 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 2017-08-07 yes yes
510-521 AT&T PACIFIC BELL – no yes
510-522 AT&T PACIFIC BELL – no yes
510-523 AT&T PACIFIC BELL – no yes
510-545 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
510-629 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
510-671 Bandwidth BANDWIDTH.COM CLEC, LLC - CA 2013-05-14 yes yes
510-682 T-Mobile METROPCS, INC. – yes yes
510-694 Onvoy ONVOY, LLC - CA 2014-12-08 yes yes
510-747 AT&T PACIFIC BELL – yes yes
510-748 AT&T PACIFIC BELL – no yes
510-749 AT&T PACIFIC BELL – no yes
510-764 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
510-769 AT&T PACIFIC BELL – no yes
510-775 Bandwidth BANDWIDTH.COM CLEC, LLC - CA 2012-09-14 yes yes
510-800 Onvoy ONVOY, LLC - CA – yes yes
510-810 T-Mobile T-MOBILE USA, INC. 2024-05-31 yes yes
510-814 AT&T PACIFIC BELL – no yes
510-846 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA – yes yes
510-863 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
510-864 AT&T PACIFIC BELL – no yes
510-865 AT&T PACIFIC BELL – no yes
510-871 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 2014-07-28 yes yes
510-872 T-Mobile METROPCS, INC. – yes yes
510-905 T-Mobile METROPCS, INC. 2018-09-17 yes yes
510-906 Onvoy ONVOY, LLC - CA 2016-07-15 yes yes
510-956 Bandwidth BANDWIDTH.COM CLEC, LLC - CA 2019-01-17 yes yes
510-975 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 2019-01-22 yes yes
510-978 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
510-995 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS – 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
PACIFIC BELL AT&T 12 28.6%
METROPCS, INC. T-Mobile 5 11.9%
LEVEL 3 COMMUNICATIONS, LLC - CA Lumen 5 11.9%
ONVOY, LLC - CA Onvoy 4 9.5%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA Verizon 4 9.5%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC Verizon 3 7.1%
BANDWIDTH.COM CLEC, LLC - CA Bandwidth 3 7.1%
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS TPx 2 4.8%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA Verizon 1 2.4%
TELEPORT COMMUNICATIONS AMERICA, LLC - CA AT&T 1 2.4%
LEVEL 3 TELECOM OF CALIFORNIA, LP - CA Lumen 1 2.4%
T-MOBILE USA, INC. T-Mobile 1 2.4%

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 OKLD ALMD in area code 510?

42 blocks: 205, 214, 217, 227, 239, 254, 263, 306, 337, 355, 373, 473 and 30 more, all listed in the table above.

Which carriers have numbers in OKLD ALMD?

PACIFIC BELL (12 blocks), METROPCS, INC. (5 blocks), LEVEL 3 COMMUNICATIONS, LLC - CA (5 blocks), ONVOY, LLC - CA (4 blocks), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA (4 blocks), MCIMETRO ACCESS TRANSMISSION SERVICES LLC (3 blocks). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is OKLD ALMD 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 510

All 785 prefixes in 510