Prefix 206-503 — Seattle, WA

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

Area code
206
Prefix (NXX)
503
Rate center
Seattle
State
Washington
Time zone
Pacific
Code holder
T-MOBILE USA, INC.
OCN
6529
Pooled
Yes (thousands-block pooling)
Assigned
2016-11-21
LATA
674

Numbers in the 206-503 prefix are registered to the Seattle rate center in WA, inside area code 206. The prefix is the second block of a ten-digit US number (206-503-XXXX) and pins the number to a billing locality.

The assigned code holder is T-MOBILE USA, INC., operating company number 6529, assigned November 21, 2016. This is a pooled prefix — expect numbers within it to be split across more than one carrier in 1,000-number blocks.

The rate center lies in the Seattle-Tacoma-Bellevue, WA Metropolitan Statistical Area. The serving LATA is 674. Local time follows the Pacific zone.

Spoofing means this prefix on your screen doesn't guarantee a Seattle caller. Verify independently before trusting a request for money or data.

Neighboring prefixes

Prefixes adjacent to 206-503
PrefixRate centerCode holder
206-500 Seattle QWEST CORPORATION
206-501 Seattle T-MOBILE USA, INC.
206-502 Bainbridge Island PEERLESS NETWORK OF WASHINGTON, LLC - WA
206-504 Seattle QWEST CORPORATION
206-505 Seattle TELEPORT COMMUNICATIONS AMERICA, LLC - WA
206-506 Seattle QWEST CORPORATION

FAQ

Where is 206-503 located?

The prefix is assigned to the Seattle rate center in WA, area code 206. It is part of the Seattle-Tacoma-Bellevue, WA Metropolitan Statistical Area.

Which company owns 206-503 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 206-503 safe to answer?

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