NumberResearch Membership · Data 09/29/2026

Recent prefix assignments

347 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/29/2026

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
8X8, INC. 43
NEW CINGULAR WIRELESS PCS, LLC - DC 28
Rogers Communications Canada Inc. (Wireless) 23
NEW CINGULAR WIRELESS PCS, LLC - IL 23
ONVOY, LLC - CA 19
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
— 573-421 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DEXTER MO
— 573-422 4XXX5XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 VIENNA MO
— 573-423 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - MO 093F BELLEVIEW MO
— 573-424 none assigned yet which blocks → T-MOBILE USA, INC. 6529 COLUMBIA MO
— 573-425 0XXX2XXX3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → ONVOY, LLC - MO 093F HUNNEWELL MO
— 573-426 0XXX4XXX7XXX · 2 holders which blocks → FIDELITY CABLEVISION, LLC 3275 ROLLA MO
— 573-427 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHARLESTON MO
— 573-429 9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 POPLAR BLF MO
— 573-431 not yet reported which blocks → SOUTHWESTERN BELL 9533 FLAT RIVER MO
— 573-432 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → ONVOY, LLC - MO 093F IRONTON MO
— 573-434 3XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 LKOZKOSBCH MO
— 573-435 2XXX3XXX4XXX5XXX8XXX · 3 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 EDGAR SPG MO
— 573-436 3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 POTOSI MO
— 573-437 0XXX which blocks → FIDELITY TELEPHONE, LLC 1882 OWENSVILLE MO
— 573-438 not yet reported which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 POTOSI MO
— 573-439 not yet reported which blocks → MARK TWAIN RURAL TEL. CO. 1914 PHILA MO
— 573-440 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 FREDERCKTN MO
— 573-441 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-442 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-443 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-444 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 FREDERCKTN MO
— 573-445 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-446 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-447 6XXX7XXX8XXX9XXX · 3 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-448 0XXX4XXX6XXX7XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 GIDEON MO
— 573-449 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-450 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CAPEGIRARD MO
— 573-454 0–9 XXXall 10 · 8 holders which blocks → BANDWIDTH.COM CLEC, LLC - MO 993E FLAT RIVER MO
— 573-455 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 WESTPHALIA MO
— 573-457 7XXX which blocks → FIDELITY TELEPHONE, LLC 1882 SPRING BLF MO
— 573-458 1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 ROLLA MO
— 573-459 5XXX9XXX which blocks → FIDELITY TELEPHONE, LLC 1882 LYON MO
— 573-461 not yet reported which blocks → ELLINGTON TEL. CO. 1874 CLEARWATER MO
— 573-462 1XXX2XXX3XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 JEFFERSNCY MO
— 573-463 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → ONVOY, LLC - MO 093F BUNKER MO
— 573-465 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 ROLLA MO
— 573-466 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 ROLLA MO
— 573-467 4XXX which blocks → T-MOBILE USA, INC. 6529 ROLLA MO
— 573-468 0XXX which blocks → FIDELITY TELEPHONE, LLC 1882 SULLIVAN MO
— 573-470 none assigned yet which blocks → UNITED STATES CELLULAR - MO 6275 BOWLNGGREN MO
— 573-471 not yet reported which blocks → SOUTHWESTERN BELL 9533 SIKESTON MO
— 573-472 not yet reported which blocks → SOUTHWESTERN BELL 9533 SIKESTON MO
— 573-473 none assigned yet which blocks → SOUTHWESTERN BELL 9533 MEXICO MO
— 573-474 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-475 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 SIKESTON MO
— 573-477 5XXX6XXX · 2 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 ST THOMAS MO
— 573-478 not yet reported which blocks → MARK TWAIN RURAL TEL. CO. 1914 DURHAM MO
— 573-480 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LKOZKOSBCH MO
— 573-481 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SIKESTON MO
— 573-482 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 FARMINGTON MO

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/29/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.