Prefix 503-309 — Portland, OR

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

Area code
503
Prefix (NXX)
309
Rate center
Portland
State
Oregon
Time zone
Pacific
Code holder
T-MOBILE USA, INC.
OCN
6529
Pooled
Yes (thousands-block pooling)
LATA
672

503-309 identifies a block of numbers in Portland, OR, within the 503 area code. Every US prefix is tied to exactly one rate center; this one is Portland.

The rate center lies in the Portland-Vancouver-Hillsboro, OR-WA Metropolitan Statistical Area. The serving LATA is 672. Local time follows the Pacific zone.

Treat the on-screen number as a hint, not evidence — 503-309 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 T-MOBILE USA, INC. (OCN 6529) as the code holder. Because 503-309 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.

Neighboring prefixes

Prefixes adjacent to 503-309
PrefixRate centerCode holder
503-306 Portland QWEST CORPORATION
503-307 Portland CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OR
503-308 Clatskanie TELEPORT COMMUNICATIONS AMERICA, LLC - OR
503-310 Portland CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OR
503-312 Portland CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OR
503-313 Portland CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OR

FAQ

Where is 503-309 located?

The prefix is assigned to the Portland rate center in OR, area code 503. It is part of the Portland-Vancouver-Hillsboro, OR-WA Metropolitan Statistical Area.

Which company owns 503-309 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 503-309 safe to answer?

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