SAN PEDRO prefixes in area code 310
NANPA records 35 assigned NXX blocks to rate center SAN PEDRO in area code 310, 4.5% 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. 7 holders hold those blocks, the largest being PACIFIC BELL (22), T-MOBILE USA, INC. (5), ONVOY, LLC - CA (3). The earliest assignment on record here is 2004-11-17 and the most recent 2025-11-20. 19 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.
Prefixes assigned here
| Prefix | Holder of record | Assigned | Pooled | In service |
|---|---|---|---|---|
| 310-221 | AT&T PACIFIC BELL | – | yes | yes |
| 310-233 | AT&T PACIFIC BELL | – | no | yes |
| 310-241 | AT&T PACIFIC BELL | – | yes | yes |
| 310-427 | Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | – | yes | yes |
| 310-507 | Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | – | yes | yes |
| 310-513 | AT&T PACIFIC BELL | – | yes | yes |
| 310-514 | AT&T PACIFIC BELL | – | yes | yes |
| 310-518 | AT&T PACIFIC BELL | – | no | yes |
| 310-519 | AT&T PACIFIC BELL | – | no | yes |
| 310-521 | AT&T PACIFIC BELL | – | no | yes |
| 310-522 | AT&T PACIFIC BELL | – | no | yes |
| 310-547 | AT&T PACIFIC BELL | – | yes | yes |
| 310-548 | AT&T PACIFIC BELL | – | no | yes |
| 310-549 | AT&T PACIFIC BELL | – | no | yes |
| 310-684 | T-Mobile T-MOBILE USA, INC. | – | yes | yes |
| 310-707 | TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | – | yes | yes |
| 310-731 | Onvoy ONVOY, LLC - CA | 2025-11-20 | yes | yes |
| 310-732 | AT&T PACIFIC BELL | – | no | yes |
| 310-758 | Onvoy ONVOY, LLC - CA | 2023-06-26 | yes | yes |
| 310-809 | T-Mobile T-MOBILE USA, INC. | – | yes | yes |
| 310-816 | AT&T PACIFIC BELL | – | no | yes |
| 310-830 | AT&T PACIFIC BELL | – | no | yes |
| 310-831 | AT&T PACIFIC BELL | – | no | yes |
| 310-832 | AT&T PACIFIC BELL | – | no | yes |
| 310-833 | AT&T PACIFIC BELL | – | no | yes |
| 310-834 | AT&T PACIFIC BELL | – | no | yes |
| 310-835 | AT&T PACIFIC BELL | – | no | yes |
| 310-847 | AT&T PACIFIC BELL | – | yes | yes |
| 310-872 | T-Mobile T-MOBILE USA, INC. | – | yes | yes |
| 310-935 | Onvoy ONVOY, LLC - CA | 2011-02-22 | yes | yes |
| 310-952 | AT&T PACIFIC BELL | – | no | yes |
| 310-971 | Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | – | yes | yes |
| 310-982 | T-Mobile T-MOBILE USA, INC. | 2005-08-30 | yes | yes |
| 310-984 | Lumen LEVEL 3 COMMUNICATIONS, LLC - CA | 2004-11-17 | yes | yes |
| 310-987 | T-Mobile T-MOBILE USA, INC. | 2005-02-14 | 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
| Holder | Brand | Blocks | Share here |
|---|---|---|---|
| PACIFIC BELL | AT&T | 22 | 62.9% |
| T-MOBILE USA, INC. | T-Mobile | 5 | 14.3% |
| ONVOY, LLC - CA | Onvoy | 3 | 8.6% |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | Verizon | 2 | 5.7% |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | Verizon | 1 | 2.9% |
| U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | TPx | 1 | 2.9% |
| LEVEL 3 COMMUNICATIONS, LLC - CA | Lumen | 1 | 2.9% |
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 SAN PEDRO in area code 310?
35 blocks: 221, 233, 241, 427, 507, 513, 514, 518, 519, 521, 522, 547 and 23 more, all listed in the table above.
Which carriers have numbers in SAN PEDRO?
PACIFIC BELL (22 blocks), T-MOBILE USA, INC. (5 blocks), ONVOY, LLC - CA (3 blocks), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA (2 blocks), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA (1 block), U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.
Is SAN PEDRO 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.