Cities in area code 831
831 numbers are anchored to 24 rate centers across California. Each row shows how many active prefixes the locality holds — a direct measure of its numbering footprint.
Salinas, Santa Cruz, Monterey, Watsonville, Hollister, Aptos, Carmel and Ben Lomond hold the largest prefix inventories; and 15 smaller communities down to single-prefix localities. Each locality below links to its rate-center page with the full prefix list.
Metropolitan coverage: 8 rate centers belong to FCC top-100 metro areas.
Overlap note: 2 localities are shared with other area codes, so a neighbor's number may differ in its first three digits.
Clock-wise the coverage is Pacific.
A caller's real location can differ: numbers port between carriers and follow their owners when they move. Use the prefix tables to see where a specific number block was issued.
| Locality (rate center) | Active prefixes | Metro area | All codes serving it |
|---|---|---|---|
| Salinas | 83 | — | 408, 831 |
| Santa Cruz | 75 | — | 831 |
| Monterey | 63 | — | 831 |
| Watsonville | 30 | San Jose-Sunnyvale-Santa Clara, CA | 831 |
| Hollister | 22 | San Jose-Sunnyvale-Santa Clara, CA | 408, 831 |
| Aptos | 19 | — | 831 |
| Carmel | 12 | — | 831 |
| Ben Lomond | 11 | — | 831 |
| Felton | 9 | — | 831 |
| Boulder Creek | 9 | San Francisco-Oakland-Fremont, CA | 831 |
| Soledad | 8 | — | 831 |
| Greenfield (monterey) | 7 | — | 831 |
| King City | 7 | San Jose-Sunnyvale-Santa Clara, CA | 831 |
| Gonzales | 7 | — | 831 |
| Big Sur | 6 | — | 831 |
| Tres Pinos | 6 | San Jose-Sunnyvale-Santa Clara, CA | 831 |
| Castroville | 6 | — | 831 |
| Carmel Valley | 5 | — | 831 |
| San Ardo | 4 | — | 831 |
| Chualar | 4 | — | 831 |
| San Juan | 4 | San Jose-Sunnyvale-Santa Clara, CA | 831 |
| San Lucas | 4 | — | 831 |
| Pinnacles | 1 | San Jose-Sunnyvale-Santa Clara, CA | 831 |
| Idria | 1 | San Jose-Sunnyvale-Santa Clara, CA | 831 |
FAQ
What is the biggest city in area code 831?
Salinas holds the most active prefixes (83), making it the code's largest numbering locality.
How many places does 831 cover?
24 rate centers in California hold active 831 prefixes, from Salinas down to communities with a single prefix.
Does a 831 number guarantee the caller lives in one of these places?
No — the tables show where number blocks were issued. Porting and VoIP let people keep or acquire numbers anywhere.