The 310 area code covers Santa Monica, Gardena and 14 more places in California.
Area code 310 is in California, on Pacific Time. In the 310 area, phone numbers are given out in Los Angeles County. It has been in service since November 2, 1991. 424 covers the same area, so two neighbours can have different area codes.
- Where
- Los Angeles County, California
- Time zone
- Pacific Time
- In service since
- November 2, 1991
- Shares its area with
- 424 (since 2006)
- Prefixes in use
- 786
- How to dial
- Local calls need 1, then the area code, then the number: 1-310-555-0142.
Find out who called you from a 310 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (310) number is on today, use our free carrier lookup.
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Santa Monica holds 18% of the phone prefixes in area code 310.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 786 prefixes in use shows where 310 numbers are actually given out.
- Santa Monica138 prefixes, 18%
- Gardena124 prefixes, 16%
- Beverly Hills113 prefixes, 14%
- West Los Angeles69 prefixes, 9%
- Inglewood49 prefixes, 6%
- Redondo Beach44 prefixes, 6%
- Compton44 prefixes, 6%
- El Segundo39 prefixes, 5%
Also served: Culver City, San Pedro, Torrance and Hawthorne and 4 smaller places.
Pacific Bell (AT&T) holds the most phone number prefixes in area code 310: 255 of 786.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 786 prefixes in use in 310 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| Pacific Bell (AT&T)AT&T's landline company | 255 | 32% |
| FrontierLandline company | 137 | 17% |
| AT&T MobilityMobile network | 68 | 9% |
| T-MobileMobile network | 58 | 7% |
| Level 3 (Lumen)Lumen's business and wholesale network | 31 | 4% |
| SpokPaging network | 24 | 3% |
| 16 other carriers | 213 | 27% |
45% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
310 has been split once and overlaid once since 1991.
1991
310 starts on November 2, 1991, split off from 213.
1997
On January 25, 1997, 562 splits off and takes part of the 310 area.
2006
On August 26, 2006, 424 is added on top of 310, so new numbers here can get either code.
A 310 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
The area codes closest to 310 are 562, 213 and 818.
This list measures the distance between the centres of each area, across state lines, and shows codes that share one area together.
California has 40 other area codes.
These are the questions people ask most about area code 310.
Where is area code 310?
310 covers Santa Monica, Gardena, Beverly Hills and West Los Angeles and 12 more places in California. In the 310 area, phone numbers are given out in Los Angeles County.
What state is area code 310 in?
California. 310 is a California area code on Pacific Time.
What cities use area code 310?
The places holding the most 310 prefixes are Santa Monica, Gardena, Beverly Hills, West Los Angeles, Inglewood, Redondo Beach, Compton and El Segundo, out of 16 places in all. The count comes from NANPA's prefix assignments as of October 1, 2026.
Which phone company owns area code 310?
No single phone company owns 310. NANPA's records show Pacific Bell (AT&T) holds the most 310 prefixes, 255 of 786, followed by Frontier and AT&T Mobility. Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 310 in?
310 is on Pacific Time.
When did area code 310 start?
310 went into service on November 2, 1991, when it was split off from 213.
Is 310 the same area as 424?
Yes. 424 (since 2006) covers the same ground as 310. Nobody's number changed when it was added; new lines simply get whichever code has numbers left, so two neighbours can have different codes.
How do I dial a 310 number?
Local calls need 1, then the area code, then the number: 1-310-555-0142.
Is 310 a toll-free number?
No. 310 is a regular area code for Santa Monica and Gardena in California, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
What area codes are near 310?
The closest are 562 (Long Beach, California), 213/323/738 (Los Angeles, California), 818/747 (Van Nuys, California) and 714/657 (Anaheim, California), measured between the centres of each area.
Who called me from a 310 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 310 a scam?
310 is a real California area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.