Area Code 831

About Area Code 831

Area code 831 is a geographic telephone area code assigned to Salinas, California. It operates in the Pacific time zone and was first introduced in 1998. Split from 408. Central coast California Monterey Bay.

Within California, area code 831 shares numbering capacity with 35 other area codes. The state's 38,965,193-person population (2023 Census Bureau estimate) is served by a combined 36 active codes, with 831 primarily responsible for the Salinas region. California's state capital is Sacramento, and its largest city is Los Angeles.

When you receive a call from a 831 number on your Caller ID, the call originated from a phone number assigned to the 831 area code — but be aware that Local Number Portability (in effect since 2003) means the caller could be physically located anywhere in the US or Canada. Area code 831 only confirms where the number was originally assigned.

Where is the 831 area code located?

Area code 831 is assigned to Salinas, California, in the Pacific time zone. The state of California uses 36 active area codes, and 831 is one of them. Calls placed from the 831 area code originate from numbers assigned by NANPA — the North American Numbering Plan Administrator — and the 831 prefix appears on Caller ID for both landline and wireless calls placed from this region.

The Pacific time zone observes Daylight Saving Time, shifting from UTC-8 to UTC-7 in summer. The local time shown above is always current, so you can quickly check whether it's a reasonable hour to call back.

What cities and counties use the 831 area code?

The 831 area code serves 9 notable cities, listed below in order of population. The largest city in the 831 territory is Los Angeles (3,898,747 residents in Los Angeles County).

• Los Angeles, CA — 3,898,747 residents (41.3% of 831 numbers)
• San Diego, CA — 1,381,611 residents (14.6% of 831 numbers)
• San Jose, CA — 971,233 residents (10.3% of 831 numbers)
• San Francisco, CA — 808,437 residents (8.6% of 831 numbers)
• Fresno, CA — 545,567 residents (5.8% of 831 numbers)
• Sacramento, CA — 524,943 residents (5.6% of 831 numbers)
• Long Beach, CA — 456,154 residents (4.8% of 831 numbers)
• Oakland, CA — 440,646 residents (4.7% of 831 numbers)
• Bakersfield, CA — 408,000 residents (4.3% of 831 numbers)

Phone number format in area code 831

All phone numbers within area code 831 follow the standard North American 10-digit format:(831) NXX-XXXX. The NXX is the central office prefix (also called an "exchange") and XXXX is the subscriber line number. For long-distance calls within the NANP, dial 1 + 831 + NXX + XXXX. From outside North America, dial your country's international access code, then 1 (the NANP country code), then the 10-digit number.

If you need to verify whether a specific 831 number is wireless, landline, or VoIP, you can use our reverse phone lookup tool. Be aware that number portability means the area code no longer guarantees the caller's physical location — only where the number was first assigned.

History of area code 831

Split from 408. Central coast California Monterey Bay.

The original 86 area codes were assigned by AT&T and Bell Labs in 1947 as part of the North American Numbering Plan. At the time, rotary-dial phones meant codes with lower digits (like 212 for NYC, 213 for LA, 312 for Chicago) were given to the largest cities because they took less time to dial. Today's area code assignments still reflect those early choices, even though touch-tone and cell phones made the original reason obsolete.

Is the 831 area code safe to answer?

Area code 831 itself is a normal geographic code with no elevated spam risk. That said, scammers can spoof any area code — including 831 — so if you don't recognize the full number, let it go to voicemail and verify the caller's identity before calling back.