WCWhoCalledLookupUS

510 Area Code — Scam Calls, Location & Who's Calling

Area code 510 serves California in the Pacific time zone, in service since 1991. The FCC has 4,435 unwanted-call complaints against 2,864 different 510 numbers on record. Look up the exact number that called you below.

Most-reported 510 numbers

Ranked by FCC unwanted-call complaints. Click a number for its full report.

510 unwanted-call complaints, last 12 months

Monthly FCC complaint volume against 510 numbers. Spikes usually mark an active robocall campaign cycling through the code.

Carriers operating in 510

Carriers assigned to 510 prefixes that visitors have looked up so far — resolved from official NPA-NXX assignment records.

  • PACIFIC BELLI · 25 prefixes
  • NEW CINGULAR WIRELESS PCS, LLCWireless · 12 prefixes
  • LEVEL 3 COMMUNICATIONS, LLC - CAC · 12 prefixes
  • T-MOBILE USA, INC.Wireless · 10 prefixes
  • CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CAWireless · 9 prefixes
  • METROPCS, INC.C · 8 prefixes
  • BANDWIDTH.COM CLEC, LLC - CAC · 8 prefixes
  • MCIMETRO ACCESS TRANSMISSION SERVICES LLCC · 7 prefixes

About area code 510

Serves
California
Time zone
Pacific
In service since
1991-09-02
Overlay
Yes — 10-digit dialing

Source: NANPA numbering records, refreshed weekly.

Spam calls from 510? What to know

Seeing repeated missed calls from 510 numbers you don't recognize is the classic signature of neighbor-spoofing robocall campaigns. The caller isn't necessarily in California — spoofing software displays whatever digits the campaign chooses. Never call unknown numbers back; look them up first, and report unwanted calls to the FCC to build the public record.

Area code 510 FAQs

Where is area code 510?

Area code 510 serves California, in the Pacific time zone. It is part of an overlay complex, so multiple area codes serve the same territory and 10-digit dialing is required. It has been in service since 1991.

Why do I keep getting calls from 510 numbers?

Robocallers use "neighbor spoofing" — displaying a number with a local area code to make you more likely to answer. A call showing area code 510 may not originate from California at all. Look up the full 10-digit number on this site to see its complaint history before calling back.

Are 510 numbers safe to call back?

Area codes themselves are neither safe nor unsafe — 510 contains millions of legitimate lines alongside any spoofed or spam numbers. The FCC has logged 4,435 unwanted-call complaints against 2,864 distinct 510 numbers in our current data window. Check the specific number's report page before returning a missed call.