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

Learn more about overlay and split area codes →

Demographics & Economics

Total Population: 1,361,611
Population Density: 2,227 people/sq mi
above U.S. average (U.S.: 93 people/sq mi)
Median Household Income: $87,760
above U.S. median (U.S.: $75,144)
Poverty Rate: 13.6%
above U.S. average (U.S.: 11.5%)
Unemployment Rate: 7.0%
above U.S. average (U.S.: 3.6%)
Education Attainment: Bachelor's Degree+
35.5%
near U.S. average (U.S.: 33.7%)
High School or Lower
31.9%

Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.

See how this area code compares to all US area codes in the income ranking and density ranking.

Time Zone

Pacific Time (PT)

NANPA Relief Status

According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.

Source: NANPA NPA Relief Planning Reports · See all relief planning statuses

Current Time

Pacific Time (PT)

Prefix Utilization

Geographic Coverage

State

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

Area Code 840 geographic coverage map (light mode)

Demographics

The estimated population served by area code 840 is approximately 1,361,611. The population density is 2,227 people per square mile, which is higher than the national average of 93. The median household income is $87,760, which is higher than the national median of $75,144. Approximately 35.5% of adults hold a bachelor's degree or higher, compared to the national rate of 33.7%. This rate is near the national average. The poverty rate stands at 13.6%, which is higher than the national rate of 11.5%.

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.