Area code
310
310 is a United States area code. Under the North American Numbering Plan it belongs to California, which has 41 area codes in total.
Validate a number in 310
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Area code 310 at a glance
NANPA lists 786 central office codes (prefixes) in use in area code 310, held by 24 holders across 17 rate centers.
| Fact | Value |
|---|---|
| In service since | 1991-11-02 |
| Time zone | Pacific (P) |
| Assigned overlays | 424 (2006-08-26) |
| Prefixes in use | 786 |
| Pooled prefixes | 354 (45%) |
| Rate centers | 17 |
| Companies holding prefixes | 24 |
| Assignment dates on file | 2001-02-28 to 2025-11-20 (101 prefixes) |
| ZIP codes in its places | 43 |
Rate centers in area code 310
| Rate center | Prefixes | Share |
|---|---|---|
| CMTN GRDN | 124 | 16% |
| BEVERLYHLS | 113 | 14% |
| SNMN SNMN | 84 | 11% |
| W ANGELES | 69 | 9% |
| SNMN MRVS | 54 | 7% |
| INGLEWOOD | 49 | 6% |
| CMTN CMTN | 44 | 6% |
| REDONDO | 44 | 6% |
| 9 other rate centers | 205 | 26% |
Who holds the prefixes in 310
Pacific Bell holds the most prefixes, 249 (32%). 45% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
| Holder | Prefixes | Share |
|---|---|---|
| Pacific Bell | 249 | 32% |
| Frontier California | 137 | 17% |
| New Cingular Wireless PCS | 68 | 9% |
| T-Mobile USA | 58 | 7% |
| Verizon Wireless | 56 | 7% |
| Mcimetro Access Transmission Services | 46 | 6% |
| 18 other carriers | 172 | 22% |
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. Find which carrier a number is on, or browse the prefix holders.
History of area code 310
- 1947-01-01 Area code 213, named as the parent of 310 in the NANPA report, was in service.
- 1991-11-02 Area code 310 went into service.
- 1997-01-25 Area code 562 went into service and names 310 as its parent.
- 2006-08-26 Area code 424 went into service as an overlay in the same area as 310.
Area codes nearest to 310
Distance is measured between the centers of the ZIP code places each area code serves, so it is a rough guide.
Overlay codes in the same area
ZIP codes in area code 310
43 ZIP codes fall in places that have a rate center in this area code.
| Place | ZIP codes |
|---|---|
| Inglewood, CA | 12 |
| Torrance, CA | 10 |
| Lakewood, CA | 5 |
A ZIP code and an area code are unrelated systems. A ZIP code can sit in more than one area code, and an area code spans many ZIP codes.
Complaints on file for 310 numbers
5,504 FCC complaints are on file for 3,708 numbers in 310, most often filed as "Unwanted Calls". These are unverified consumer reports.
| Year of latest complaint | Numbers |
|---|---|
| 2023 | 142 |
| 2024 | 114 |
| 2025 | 104 |
Other area codes in California
California is one state with 41 area codes in the NANPA table. 310 is one of them.
- 209
- 213
- 279
- 323
- 341
- 350
- 357
- 369
- 408
- 415
- 424
- 442
- 510
- 530
- 559
- 562
- 619
- 626
- 628
- 650
- 657
- 661
- 669
- 707
- 714
- 738
- 747
- 760
- 805
- 818
- 820
- 831
- 837
- 840
- 858
- 909
- 916
- 925
- 949
- 951
Next to 310 in the numbering table
These are the codes just before and after 310 when all are sorted by number. They are neighbours on the list, not necessarily on the map.
What the area code does and does not tell you
A number that starts with 310 was first assigned in California. That is a fact about where the number began, and it is a useful hint when you check a form entry, for example a billing address in California next to a 310 phone number.
It does not show where the person is today. A number stays with its owner after a move or a change of provider (number portability), and mobile numbers travel with the handset. The area code also cannot tell you whether the line is active, who the carrier is, or whether the number is mobile or fixed: the plan shares those ranges. Read more about the area code, the numbering plan and line type.
Check numbers in bulk with the API
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
| Phone Intelligence (carrier and line status) | 1 credit per check (invalid numbers outside the US and Canada are free) | Product page |
Questions about area code 310
Where is area code 310?
NANPA assigns area code 310 to California, United States.
In which state does area code 310 sit?
California. 310 is one of 41 area codes the NANPA table assigns to the state.
Which places does area code 310 cover?
The places with the most ZIP codes among the rate centers in 310 are Inglewood, CA, Torrance, CA and Lakewood, CA. The rate center list on this page shows all of them.
Who owns area code 310?
NANPA assigns area codes. Within 310, Pacific Bell holds the most prefixes, 249 prefixes or 32%.
Which time zone does 310 use?
The NANPA NPA report lists the time zone for 310 as Pacific (P).
What year did 310 enter service?
The NANPA NPA report gives an in-service date of 1991-11-02, so 310 has been in use since 1991.
Does area code 310 have an overlay?
Yes. 424 (in service 2006-08-26) shares the same area with 310, so numbers from all of them are local to each other.
Which area codes are nearest to 310?
The area codes closest to 310, measured between the centers of the ZIP code places they serve, are 562 (about 12 miles), 747 (about 22 miles), 818 (about 22 miles), 626 (about 24 miles) and 657 (about 27 miles).
How many prefixes does area code 310 have?
NANPA's report dated 2026-10-17 lists 786 prefixes in service in 310, spread over 17 rate centers and 24 holders.
Are there complaints about 310 numbers?
The FCC data on file has 5,504 complaints for 3,708 numbers in 310. They are unverified consumer reports. A number with no complaints on file is not proven safe.
Area code assignments: North American Numbering Plan Administrator NPA report, file dated 10/17/2026, retrieved 2026-10-17. Source file. New codes are assigned several times a year. Prefixes, rate centers, holders, time zone, in-service date and overlays: NANPA central office code report dated 2026-10-17 and NPA report dated 2026-10-18. Complaints: FCC consumer complaints open data, fetched 2026-10-17. ZIP code places: Postal code places and coordinates: GeoNames (geonames.org), licensed CC BY 4.0.