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 509
NEW CINGULAR WIRELESS PCS, LLC 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
— 509-495 1XXX which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-496 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 SPOKANE WA
— 509-498 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 TELECOM OF WASHINGTON, LLC - WA 7455 CHENEY WA
— 509-499 8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SPOKANE WA
— 509-500 0XXX2XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 ASOTIN WA
— 509-507 0–9 XXXall 10 · 2 holders which blocks → CALLWORKS CORPORATION 475J DEER PARK WA
— 509-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX WA
— 509-518 0–9 XXXall 10 · 5 holders which blocks → ONVOY SPECTRUM, LLC 624H KENNEWICK WA
— 509-520 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 WALLAWALLA WA
— 509-521 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PASCO WA
— 509-522 not yet reported which blocks → QWEST CORPORATION 9638 WALLAWALLA WA
— 509-523 0XXX7XXX · 2 holders which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 ROSALIA WA
— 509-524 3XXX8XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9638 WALLAWALLA WA
— 509-525 not yet reported which blocks → QWEST CORPORATION 9638 WALLAWALLA WA
— 509-526 not yet reported which blocks → QWEST CORPORATION 9638 WALLAWALLA WA
— 509-527 not yet reported which blocks → QWEST CORPORATION 9638 WALLAWALLA WA
— 509-528 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PASCO WA
— 509-529 not yet reported which blocks → QWEST CORPORATION 9638 WALLAWALLA WA
— 509-531 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PASCO WA
— 509-532 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-533 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-534 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-535 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-536 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-538 5XXX7XXX9XXX · 3 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 WILLARD WA
— 509-539 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PASCO WA
— 509-540 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 WALLAWALLA WA
— 509-542 5XXX6XXX7XXX · 3 holders which blocks → QWEST CORPORATION 9638 PASCO WA
— 509-543 not yet reported which blocks → QWEST CORPORATION 9638 PASCO WA
— 509-544 not yet reported which blocks → QWEST CORPORATION 9638 PASCO WA
— 509-545 not yet reported which blocks → QWEST CORPORATION 9638 PASCO WA
— 509-546 none assigned yet which blocks → QWEST CORPORATION 9638 PASCO WA
— 509-547 not yet reported which blocks → QWEST CORPORATION 9638 PASCO WA
— 509-548 not yet reported which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 WENATCHEE WA
— 509-549 none assigned yet which blocks → PIONEER TEL. CO. 2437 LACROSSE WA
— 509-550 0XXX1XXX2XXX3XXX5XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 NEWPORT WA
— 509-552 0XXX2XXX4XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 CLARKSTON WA
— 509-553 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 COLFAX WA
— 509-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST WA
— 509-559 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CENTURYTEL OF WASHINGTON, INC. DBA CENTURYLINK 2408 CHENEY WA
— 509-561 not yet reported which blocks → ONVOY, LLC - WA 483E SPOKANE WA
— 509-562 not yet reported which blocks → ONVOY, LLC - WA 483E SPOKANE WA
— 509-565 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 TELECOM OF WASHINGTON, LLC - WA 7455 MEDICAL LK WA
— 509-568 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-569 4XXX7XXX · 2 holders which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 ROSALIA WA
— 509-572 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 KENNEWICK WA
— 509-573 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-574 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-575 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-576 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA

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.