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
— 509-355 not yet reported which blocks → ONVOY, LLC - WA 483E SPOKANE WA
— 509-356 not yet reported which blocks → ONVOY, LLC - WA 483E SPOKANE WA
— 509-357 not yet reported which blocks → ONVOY, LLC - WA 483E SPOKANE WA
— 509-358 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-359 0XXX1XXX5XXX8XXX9XXX · 2 holders which blocks → CENTURYTEL OF WASHINGTON, INC. DBA CENTURYLINK 2408 CHENEY WA
— 509-361 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 MOSES LAKE WA
— 509-363 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-364 4XXX6XXX7XXX9XXX · 3 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 GLENWOOD WA
— 509-365 1XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 LYLE WA
— 509-366 none assigned yet which blocks → UNITED STATES CELLULAR - WA 6270 KENNEWICK WA
— 509-368 0XXX1XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-369 1XXX5XXX7XXX · 3 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 KLICKITAT WA
— 509-370 8XXX9XXX which blocks → T-MOBILE USA, INC. 6529 SPOKANE WA
— 509-371 6XXX7XXX9XXX · 2 holders which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 RICHLAND WA
— 509-372 not yet reported which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 RICHLAND WA
— 509-373 not yet reported which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 RICHLAND WA
— 509-374 6XXX7XXX which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 KENNEWICK WA
— 509-375 not yet reported which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 RICHLAND WA
— 509-376 not yet reported which blocks → ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER 4324 RICHLAND WA
— 509-377 5XXX7XXX · 2 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 COLUMBIA WA
— 509-378 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 KENNEWICK WA
— 509-381 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - WA 483E SPOKANE WA
— 509-382 5XXX6XXX7XXX · 3 holders which blocks → QWEST CORPORATION 9638 DAYTON WA
— 509-384 1XXX3XXX7XXX · 3 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 ROOSEVELT WA
— 509-386 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 WALLAWALLA WA
— 509-388 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 YAKIMA WA
— 509-389 3XXX4XXX5XXX7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SPOKANE WA
— 509-391 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 SUNNYSIDE WA
— 509-392 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 RICHLAND WA
— 509-393 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 WENATCHEE WA
— 509-394 4XXX5XXX7XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9638 TOUCHET WA
— 509-395 1XXX5XXX7XXX9XXX · 3 holders which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 TROUT LAKE WA
— 509-396 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 KENNEWICK WA
— 509-397 7XXX8XXX which blocks → QWEST CORPORATION 9638 COLFAX WA
— 509-399 0XXX3XXX4XXX7XXX9XXX · 3 holders which blocks → CENTURYTEL OF WASHINGTON, INC. DBA CENTURYLINK 2408 STARBUCK WA
— 509-402 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - WA 483E GRANDVIEW WA
— 509-411 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX WA
— 509-416 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 PASCO WA
— 509-419 0XXX1XXX2XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 COLVILLE WA
— 509-420 0–9 XXXall 10 · 7 holders which blocks → ONVOY, LLC - WA 483E RICHLAND WA
— 509-421 6XXX8XXX · 2 holders which blocks → SKYE TELECOM LLC DBA SKYETEL 622J WENATCHEE WA
— 509-422 not yet reported which blocks → QWEST CORPORATION 9638 OMAK WA
— 509-427 1XXX6XXX which blocks → UNITED TELEPHONE - NORTHWEST DBA CENTURYLINK - WA 4521 STEVENSON WA
— 509-428 2XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 RITZVILLE WA
— 509-429 4XXX5XXX6XXX7XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 OMAK WA
— 509-430 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PASCO WA
— 509-432 0XXX2XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 PULLMAN WA
— 509-433 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 WENATCHEE WA
— 509-434 2XXX4XXX6XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SPOKANE WA
— 509-435 1XXX2XXX3XXX5XXX6XXX7XXX8XXX which blocks → XO WASHINGTON, INC. 7340 SPOKANE 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.