LA MESA prefixes in area code 858
NANPA records 8 assigned NXX blocks to rate center LA MESA in area code 858, 1.4% of the 564 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 NEW CINGULAR WIRELESS PCS, LLC (3), FRACTEL, LLC (3), ONVOY, LLC - CA (1). The earliest assignment on record here is 2019-03-19 and the most recent 2025-08-22. 8 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 575, 619 – 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 |
|---|---|---|---|---|
| 858-328 | AT&T NEW CINGULAR WIRELESS PCS, LLC | 2021-10-26 | yes | yes |
| 858-387 | Onvoy ONVOY, LLC - CA | 2023-10-02 | yes | yes |
| 858-416 | AT&T NEW CINGULAR WIRELESS PCS, LLC | 2024-10-24 | yes | yes |
| 858-440 | AT&T NEW CINGULAR WIRELESS PCS, LLC | 2025-08-22 | yes | yes |
| 858-466 | FRACTEL, LLC | 2021-03-16 | yes | yes |
| 858-585 | FRACTEL, LLC | 2019-03-19 | yes | yes |
| 858-723 | NUSO, LLC | – | yes | yes |
| 858-878 | FRACTEL, LLC | 2022-02-18 | 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 |
|---|---|---|---|
| NEW CINGULAR WIRELESS PCS, LLC | AT&T | 3 | 37.5% |
| FRACTEL, LLC | – | 3 | 37.5% |
| ONVOY, LLC - CA | Onvoy | 1 | 12.5% |
| NUSO, LLC | – | 1 | 12.5% |
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 LA MESA in area code 858?
8 blocks: 328, 387, 416, 440, 466, 585, 723, 878. The table above gives the holder of each.
Which carriers have numbers in LA MESA?
NEW CINGULAR WIRELESS PCS, LLC (3 blocks), FRACTEL, LLC (3 blocks), ONVOY, LLC - CA (1 block), NUSO, 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 LA MESA 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.