Area Code 840
California
Area code 840 serves California, primarily San Bernardino, in the Pacific Time (PT) time zone. It is an overlay area code sharing territory with area code 909.
Overlay Area Code
This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.
This area code shares its geographic region with: area code 909 (San Bernardino).
In service since: 23-Feb-2021
Demographics
The estimated population served by area code 840 is approximately 2,435,966. The population density is 142 people per square mile, which is higher than the national average of 94. The median household income is $82,184, which is near the national median of $78,538. Approximately 25.3% of adults hold a bachelor's degree or higher, compared to the national rate of 35.0%. This rate is lower than the national average. The poverty rate stands at 13.4%, which is near the national rate of 12.4%.
History
Area code 840 serves as an overlay for the same territory as area code 909. It was introduced in 2021 to provide additional phone number capacity for the region. It shares its territory with area code area code 909.
Demographics & Economics
- Total Population
- 2,435,966
- Population Density
- 142 people/sq miabove U.S. average (U.S.: 94 people/sq mi)
- Median Household Income
- $82,184near U.S. median (U.S.: $78,538)
- Poverty Rate
- 13.4%near U.S. average (U.S.: 12.4%)
- Unemployment Rate
- 7.0%above U.S. average (U.S.: 5.2%)
- Education Attainment
- Bachelor's Degree+25.3%below U.S. average (U.S.: 35.0%)High School or Lower35.3%
Statistics are population-weighted aggregations from Census ACS 5-year estimates.See Sources for details.
Geographic Coverage
State
CA
Major Cities
- San Bernardino
- Fontana
- Ontario
- Rancho Cucamonga
- Pomona
- Rialto
- Chino
- Upland
- Chino Hills
- Redlands
- Eastvale
- Highland
- Yucaipa
- Colton
- Diamond Bar
- Rowland Heights
- Montclair
- Claremont
- San Dimas
- La Verne
- Walnut
- Loma Linda
- Bloomington
- Grand Terrace
and 13 more cities
Time Zone
- Pacific Time (PT)
Current Time
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 840).
| County | Population | Share |
|---|---|---|
| San Bernardino, CA | 1,780,113 | 73.1% |
| Los Angeles, CA | 422,826 | 17.4% |
| Riverside, CA | 233,027 | 9.6% |
Call Context
This area code covers a metropolitan region in CA with moderate to high population density, centered on San Bernardino and surrounding communities.
Nearby Area Codes
Area codes geographically closest to 840.
Other Area Codes in California
Area codes that also serve California, linked for easy comparison.
Frequently Asked Questions
Common questions about area code 840 and how phone numbering works.
Phone numbers assigned to area code 840 are tied to where they were originally provisioned — not the caller's current location. This code serving roughly 2436k people covers San Bernardino in CA, so a number originally set up there will retain the 840 prefix even if the owner moves or uses VoIP. Mobile phones keep their original number when users relocate, and businesses often adopt local area codes to establish a regional presence.
Start by looking up the area code on this site to understand its geographic context — area code 840 is associated with San Bernardino in CA. For caller-specific details, use your carrier's caller ID features or check public directories. If you suspect fraud, you can report it to the FTC. To file a complaint about robocalls or spoofed numbers, visit the FCC Consumer Complaint Center. You can also register with the National Do Not Call Registry.
When an area's available number pool runs low, regulators introduce an "overlay" code covering the same territory. Both codes coexist, and new numbers are assigned from whichever has availability. Area code 840 serves the San Bernardino region in CA, where growing demand for phone numbers necessitated an additional code. This area code shares its region with area code 909. Learn more in our overlay vs split guide.