Prefix 408-581 — San Jose:west Da, CA

NANPA CO code assignment, current as of July 28, 2026.

Area code
408
Prefix (NXX)
581
Rate center
San Jose:west Da
State
California
Time zone
Pacific
Code holder
NEW CINGULAR WIRELESS PCS, LLC
OCN
6010
Pooled
Yes (thousands-block pooling)
Assigned
2022-08-22
LATA
722

408-581 identifies a block of numbers in San Jose:west Da, CA, within the 408 area code. Every US prefix is tied to exactly one rate center; this one is San Jose:west Da.

The rate center lies in the San Jose-Sunnyvale-Santa Clara, CA Metropolitan Statistical Area. The serving LATA is 722. Local time follows the Pacific zone.

Treat the on-screen number as a hint, not evidence — 408-581 can be spoofed like any US prefix. If a call feels off, verify through an official callback number and file a complaint with the FCC or FTC.

NANPA's central-office code records list NEW CINGULAR WIRELESS PCS, LLC (OCN 6010) as the code holder, assigned August 22, 2022. Because 408-581 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.

Neighboring prefixes

Prefixes adjacent to 408-581
PrefixRate centerCode holder
408-578 San Jose:south Da PACIFIC BELL
408-579 San Jose:west Da U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS
408-580 San Jose:south Da T-MOBILE USA, INC.
408-582 San Jose:north Da MCIMETRO ACCESS TRANSMISSION SERVICES LLC
408-583 Campbell MCIMETRO ACCESS TRANSMISSION SERVICES LLC
408-584 Sunnyvale PACIFIC BELL

FAQ

Where is 408-581 located?

The prefix is assigned to the San Jose:west Da rate center in CA, area code 408. It is part of the San Jose-Sunnyvale-Santa Clara, CA Metropolitan Statistical Area.

Which company owns 408-581 numbers?

NEW CINGULAR WIRELESS PCS, LLC holds the code, but the prefix is pooled — individual thousands-blocks can be assigned to other carriers, and numbers may be ported to any provider.

Is a call from 408-581 safe to answer?

The prefix itself says nothing about the caller. Legitimate San Jose:west Da businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.