---
title: "Area code 858: California, United States"
url: "https://lookvalid.com/area-code/858.md"
canonical_url: "https://lookvalid.com/area-code/858"
last_updated: "2026-10-23"
type: "reference"
summary: "Area code 858 serves California, United States. Number formats, numbering rules, a live phone validator and the other codes in California."
---

# Area code 858: California, United States

Area code 858 serves California, United States. Number formats, numbering rules, a live phone validator and the other codes in California.

NANPA lists 559 central office codes (prefixes) in use in area code 858, held by 38 holders across 19 rate centers.
Pacific Bell holds the most prefixes, 151 (27%). 74% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
The FCC unwanted-call data has 2,956 complaints on file for 1,944 numbers in 858, most often filed as "Unwanted Calls". These are consumer reports, not findings.

## Facts

- In service since: 1999-06-12
- Time zone: Pacific (P)
- Assigned overlays: 619 (1982-01-01)
- Prefixes in use: 559
- Pooled prefixes: 416 (74%)
- Rate centers: 19
- Companies holding prefixes: 38
- Assignment dates on file: 2001-02-15 to 2026-08-07 (213 prefixes)
- ZIP codes in its places: 30

## Rate centers

| Rate center | Prefixes | Share |
| --- | --- | --- |
| LA JOLLA | 166 | 30% |
| SNDG LVTA | 80 | 14% |
| SNDG MRMS | 68 | 12% |
| DEL MAR | 45 | 8% |
| POWAY | 45 | 8% |
| RNCHOBRNDO | 41 | 7% |
| RNCHOPNQTS | 22 | 4% |
| SNDG SNDG | 22 | 4% |
| 11 other rate centers | 70 | 13% |

## Carriers

| Holder | Prefixes | Share |
| --- | --- | --- |
| Pacific Bell | 151 | 27% |
| New Cingular Wireless PCS | 50 | 9% |
| T-Mobile USA | 44 | 8% |
| Fractel | 35 | 6% |
| Mcimetro Access Transmission Services | 33 | 6% |
| Onvoy | 32 | 6% |
| 32 other carriers | 214 | 38% |

A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company.

## History

- 1982-01-01: Area code 619, named as the parent of 858 in the NANPA report, was in service.
- 1999-06-12: Area code 858 went into service.

## Nearest area codes

The area codes closest to 858, measured between the centers of the ZIP code places they serve, are 951 (about 76 miles), 949 (about 79 miles), 657 (about 90 miles), 714 (about 90 miles) and 909 (about 97 miles).

## ZIP codes

30 ZIP codes fall in places that have a rate center in this area code. The places with the most are Chula Vista, CA (8 ZIP codes), La Jolla, CA (5 ZIP codes) and El Cajon, CA (4 ZIP codes). A ZIP code and an area code are unrelated systems, so a ZIP code can sit in more than one area code and an area code spans many ZIP codes.

## Complaints on file

2,956 complaints for 1,944 numbers. Numbers whose latest complaint falls in each year:

- 2023: 93
- 2024: 100
- 2025: 95

## Questions

### Where is area code 858?

NANPA assigns area code 858 to California, United States.

### In which state does area code 858 sit?

California. 858 is one of 41 area codes the NANPA table assigns to the state.

### Which places does area code 858 cover?

The places with the most ZIP codes among the rate centers in 858 are Chula Vista, CA, La Jolla, CA and El Cajon, CA. The rate center list on this page shows all of them.

### Who owns area code 858?

NANPA assigns area codes. Within 858, Pacific Bell holds the most prefixes, 151 prefixes or 27%.

### Which time zone does 858 use?

The NANPA NPA report lists the time zone for 858 as Pacific (P).

### What year did 858 enter service?

The NANPA NPA report gives an in-service date of 1999-06-12, so 858 has been in use since 1999.

### Does area code 858 have an overlay?

Yes. 619 (in service 1982-01-01) shares the same area with 858, so numbers from all of them are local to each other.

### Which area codes are nearest to 858?

The area codes closest to 858, measured between the centers of the ZIP code places they serve, are 951 (about 76 miles), 949 (about 79 miles), 657 (about 90 miles), 714 (about 90 miles) and 909 (about 97 miles).

### How many prefixes does area code 858 have?

NANPA's report dated 2026-10-17 lists 559 prefixes in service in 858, spread over 19 rate centers and 38 holders.

### Are there complaints about 858 numbers?

The FCC data on file has 2,956 complaints for 1,944 numbers in 858. They are unverified consumer reports. A number with no complaints on file is not proven safe.

Sources: NANPA central office code report dated 2026-10-17; NANPA NPA report dated 2026-10-18; FCC unwanted-call complaints, data fetched 2026-10-17; ZIP code places from GeoNames (CC BY 4.0).