858 Area Code — California
858 is a North American Numbering Plan area code for California, the United States. It covers about 2,348,599 people in 29 towns and 134 ZIP codes, including San Diego, Chula Vista and El Cajon.
| Field | Value |
|---|---|
| Area code | 858 |
| Country | United States (+1) |
| State / province | California |
| Type | Shares its towns with 619 |
| Time zone | Pacific |
| Population covered | 2,348,599 |
| Towns covered | 29 |
| ZIP codes | 134 |
| Approx. centre | 32.756, -117.059 |
Where area code 858 is used
Area code 858 is assigned to California, the United States, inside the North American Numbering Plan. Numbers in the code are written (858) NXX-XXXX at home and +1 858 NXX-XXXX when dialled from outside Canada and the United States. Since the NANP moved to 10-digit dialling you must always include the area code, even for a local call.
Other area codes in this footprint: 619. They serve towns in the same territory, so a single street can contain numbers from more than one code. That is normal in the NANP and does not change how you dial.
Towns and cities in area code 858
The 29 towns below are the largest in the 858 footprint, ranked by population. Every one of them links to its own page with the full list of area codes and ZIP codes for that town.
| Town | County | Population | ZIP codes |
|---|---|---|---|
| San Diego | San Diego County | 1,329,732 | 76 |
| Chula Vista | San Diego County | 272,585 | 8 |
| El Cajon | San Diego County | 173,694 | 4 |
| La Mesa | San Diego County | 74,642 | 4 |
| Spring Valley | San Diego County | 71,078 | 4 |
| National City | San Diego County | 59,891 | 2 |
| Santee | San Diego County | 59,590 | 2 |
| Poway | San Diego County | 48,683 | 2 |
| La Jolla | San Diego County | 48,412 | 5 |
| Lakeside | San Diego County | 46,216 | 1 |
| Lemon Grove | San Diego County | 27,745 | 2 |
| Imperial Beach | San Diego County | 25,741 | 2 |
Counties covered
| County | ZIP codes |
|---|---|
| San Diego County | 134 |
Other area codes serving the same towns
Nearby area codes
How to dial area code 858
- Within North America: 858 + 7-digit number (858-NXX-XXXX). The leading 1 is optional on a mobile phone and required on most landlines for long-distance.
- From abroad: your country's international prefix, then 1, then 858, then the 7-digit number — for example 00 1 858 NXX-XXXX from most of Europe.
Frequently asked questions
What area code is 858?
858 is a North American Numbering Plan area code assigned to California, the United States. It covers about 2,348,599 people in 29 towns.
Is 858 a US or Canadian area code?
858 is a United States area code. Canada and the United States share the +1 country code, so both are part of the same numbering plan.
What time zone is area code 858 in?
Area code 858 is in the Pacific time zone.
Do I have to dial 10 digits?
Yes. Every NANP call now requires the area code plus the seven-digit number, even for a local call.