Area Code 831

California

Area code 831 serves California, primarily Salinas, in the Pacific Time (PT) time zone. It was created from a split of area code 408.

Published: February 17, 2026Verified against NANPA and FCC records

Split Area Code

This area code exists because its parent region ran low on available numbers: the parent territory was divided geographically, this code took over one part of it, and the parent kept serving the rest. Existing customers generally keep their numbers — only the code changes for the newly drawn region.

This area code was split from area code 408 (San Jose).

In service since: 11-Jul-1998

Learn more about overlay and split area codes →

Demographics & Economics

Total Population: 1,004,963
Population Density: 165 people/sq mi
above U.S. average (U.S.: 95 people/sq mi)
Median Household Income: $97,230
above U.S. median (U.S.: $80,734)
Poverty Rate: 11.1%
below U.S. average (U.S.: 12.5%)
Unemployment Rate: 5.4%
near U.S. average (U.S.: 5.2%)
Education Attainment: Bachelor's Degree+
36.1%
near U.S. average (U.S.: 35.7%)
High School or Lower
30.9%

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

Salinas
Santa Cruz
Watsonville
Hollister
Seaside
Monterey
Soledad
Marina
Greenfield
Prunedale
Live Oak
Pacific Grove
Scotts Valley
Soquel
Capitola
Rio del Mar
Gonzales
Interlaken
Castroville
Ben Lomond
Aptos
Pleasure Point
Boulder Creek
Felton

and 39 more cities

Area Code 831 geographic coverage map (light mode)

Demographics

The estimated population served by area code 831 is approximately 1,004,963. The population density is 165 people per square mile, which is higher than the national average of 95. The median household income is $97,230, which is higher than the national median of $80,734. Approximately 36.1% of adults hold a bachelor's degree or higher, compared to the national rate of 35.7%. This rate is near the national average. The poverty rate stands at 11.1%, which is lower than the national rate of 12.5%.

History

Area code 831 was created from a split of area code 408. It was introduced in 1998 as part of a geographic division to provide additional numbering resources.