NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

1 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, last 30 days — NPA 503
ONVOY, LLC - OR 1
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 503-376 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OR 3234 MCMINNVL OR
— 503-377 not yet reported which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - OR 4520 BAY CITY OR
— 503-378 not yet reported which blocks → QWEST CORPORATION 9638 SALEM OR
— 503-379 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - OR 3234 MCMINNVL OR
— 503-380 not yet reported which blocks → T-MOBILE USA, INC. 6529 PORTLAND OR
— 503-381 none assigned yet which blocks → T-MOBILE USA, INC. 6529 PORTLAND OR
— 503-382 7XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OR 7531 PORTLAND OR
— 503-383 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OR 7531 SALEM OR
— 503-384 2XXX8XXX · 2 holders which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-385 1XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OR 7531 SALEM OR
— 503-387 0XXX1XXX3XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OR 7531 CLACKAMAS OR
— 503-389 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NORTH PL OR
— 503-390 not yet reported which blocks → QWEST CORPORATION 9638 SALEM OR
— 503-391 not yet reported which blocks → QWEST CORPORATION 9638 SALEM OR
— 503-392 not yet reported which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - OR 4520 CLOVERDALE OR
— 503-393 not yet reported which blocks → QWEST CORPORATION 9638 SALEM OR
— 503-394 not yet reported which blocks → SCIO MUTUAL TEL. CO. 2397 SCIO OR
— 503-395 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OR 7531 RAINIER OR
— 503-396 3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OR 5820 ST HELENS OR
— 503-397 not yet reported which blocks → QWEST CORPORATION 9638 ST HELENS OR
— 503-398 not yet reported which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - OR 4520 BEAVER OR
— 503-399 not yet reported which blocks → QWEST CORPORATION 9638 SALEM OR
— 503-401 not yet reported which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-402 not yet reported which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-403 8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BEAVERTON OR
— 503-404 3XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 STFRD-SNDY OR
— 503-405 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GRESHAM OR
— 503-406 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OR 3234 CLACKAMAS OR
— 503-407 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OR 5820 PORTLAND OR
— 503-408 not yet reported which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-409 not yet reported which blocks → T-MOBILE USA, INC. 6529 SALEM OR
— 503-410 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → METROPCS, INC. 5562 ST HELENS OR
— 503-411 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX OR
— 503-412 8XXX9XXX which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-413 0XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-414 not yet reported which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-415 0XXX1XXX9XXX which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-416 not yet reported which blocks → LEVEL 3 TELECOM OF OREGON, LLC - OR 7537 PORTLAND OR
— 503-417 not yet reported which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-418 not yet reported which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-419 6XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PORTLAND OR
— 503-420 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 DALLAS OR
— 503-421 none assigned yet which blocks → T-MOBILE USA, INC. 6529 PORTLAND OR
— 503-422 4XXX which blocks → T-MOBILE USA, INC. 6529 PORTLAND OR
— 503-423 7XXX which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-424 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - OR 3234 BEAVERTON OR
— 503-425 9XXX which blocks → QWEST CORPORATION 9638 PORTLAND OR
— 503-426 not yet reported which blocks → NORTH COUNTY COMMUNICATION CORPORATION - OR 8294 PORTLAND OR
— 503-427 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OR 3234 STFRD-SNDY OR
— 503-428 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SALEM OR

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.