Area codes · +1
Area code 858
Area code 858 covers La Jolla, California. We hold 4,668 allocated blocks for it across 19 rate centres, split 35% mobile, 51% landline and 14% VoIP.
The other area codes laid over 858
Area code 858 does not have La Jolla to itself. 1 other code — 619 — serves the same rate centres, laid over the same ground rather than dividing it. That is an overlay: a new code added when the old one ran out of numbers, covering the same streets. Two neighbours can hold different area codes, so the code says roughly when a number was issued rather than where it sits.
6196,005 blocks, 17 rate centres, mostly mobile
Each holds its own blocks and its own carrier mix, so a 858 number and a 619 number from the same street can report different line types. Filtering La Jolla by area code needs all 2 of them.
858 is not confined to La Jolla itself: its blocks sit across 19 rate centres, named in the table below.
California is split across 40 area codes — 657, 707, 559, 209, 530, 858 and others. By allocated blocks 858 is the 26th largest of them, holding 3% of the California total.
Where 858 numbers are concentrated
NANPA truncates rate-centre names to ten characters and drops the spaces, which is why Sndg Lvta and Sndg Mrms are shortened. Names are reproduced as recorded rather than expanded — the abbreviation is the key the block data is filed under.
| Rate centre | Blocks | Share of 858 |
|---|---|---|
| La Jolla | 1,202 | 26% |
| Sndg Lvta | 640 | 14% |
| Sndg Mrms | 640 | 14% |
| Del Mar | 372 | 8% |
| Poway | 340 | 7% |
| Rnchobrndo | 307 | 7% |
| Sndg Sndg | 238 | 5% |
| Rnchopnqts | 196 | 4% |
| Chulavista | 191 | 4% |
| El Cajon | 151 | 3% |
| Rnchosanfe | 132 | 3% |
| La Mesa | 88 | 2% |
| Nationalcy | 54 | 1% |
| Coronado | 36 | 1% |
| Harbsnalpn | 22 | 0% |
| Pinevalley | 12 | 0% |
| Campo | 11 | 0% |
| Dulzura | 9 | 0% |
| Jacumba | 9 | 0% |
Carriers holding the most 858 blocks
Onvoy634 blocks
Pacific Bell561 blocks
AT&T Wireless486 blocks
Verizon Wireless383 blocks
T-Mobile USA, Inc.307 blocks
Bandwidth240 blocks
The largest holder, Onvoy, has 14% of the code.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 858 number still reports the carrier it started with. Closing that gap needs a live query against the routing database. How line type is derived.
Check a single 858 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 858?
Area code 858 covers La Jolla, California. It is not the only code there: 619 is an overlay on the same rate centres, so a La Jolla, California number can start with any of them.
Is a 858 number a mobile or a landline?
It can be either, and the digits do not say which. North American mobile and landline numbers share the same ranges, so the answer comes from the carrier holding the block. In 858 the split runs 35% mobile, 51% landline and 14% VoIP, so landline is the most likely single answer.
Which carriers hold 858 numbers?
The largest holders are Onvoy, Pacific Bell, AT&T Wireless. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 858 numbers are there?
The code holds 4,668 allocated blocks in our copy of the numbering plan. A block is 1,000 or 10,000 consecutive numbers depending on how deeply it has been pooled, so 858 covers on the order of 4,668,000 possible numbers — most of which have never been issued to anyone.