Prefix 408-390 — San Jose:west Da, CA

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

408-390 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 — 408-390 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.

Code-holder of record: T-MOBILE USA, INC. (OCN 6529), assigned April 25, 2001. The prefix is pooled: its ten thousands-blocks can be shared among several carriers, so different 408-390 numbers may be served by different companies.

Neighboring prefixes

FAQ

Where is 408-390 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 408-390 numbers?

T-MOBILE USA, INC. 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 408-390 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.