NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

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, all time — NPA 440
OHIO BELL TEL CO 124
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 115
LEVEL 3 COMMUNICATIONS, LLC - OH 68
T-MOBILE USA, INC. 62
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 52
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
— 440-510 3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 WILLOUGHBY OH
— 440-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX OH
— 440-512 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 BEREA OH
— 440-516 7XXX9XXX · 2 holders which blocks → OHIO BELL TEL CO 9321 WICKLIFFE OH
— 440-519 not yet reported which blocks → OHIO BELL TEL CO 9321 CHAGRINFLS OH
— 440-520 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WILLOUGHBY OH
— 440-522 7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LORAIN OH
— 440-523 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CLEVELAND OH
— 440-525 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 WILLOUGHBY OH
— 440-526 not yet reported which blocks → OHIO BELL TEL CO 9321 BRECKSVL OH
— 440-527 1XXX3XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 WILLOUGHBY OH
— 440-528 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FIRST COMMUNICATIONS, LLC 460K CHAGRINFLS OH
— 440-530 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 WILLOUGHBY OH
— 440-534 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 MENTOR OH
— 440-535 0XXX1XXX2XXX5XXX · 4 holders which blocks → SIGECOM, LLC DBA WOW INTERNET CABLE AND PHONE 735E NORTHEATON OH
— 440-536 1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → METROPCS, INC. 5562 ASHTABULA OH
— 440-537 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 WILLOUGHBY OH
— 440-539 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CLEVELAND OH
— 440-540 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 BEDFORD OH
— 440-542 not yet reported which blocks → OHIO BELL TEL CO 9321 CHAGRINFLS OH
— 440-543 not yet reported which blocks → WINDSTREAM WESTERN RESERVE, INC. 0666 BAINBRIDGE OH
— 440-544 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 HILLCREST OH
— 440-545 0XXX1XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 VICTORY OH
— 440-546 not yet reported which blocks → OHIO BELL TEL CO 9321 BRECKSVL OH
— 440-547 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 WILLOUGHBY OH
— 440-548 1XXX which blocks → WINDSTREAM WESTERN RESERVE, INC. 0666 PARKMAN OH
— 440-549 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 WICKLIFFE OH
— 440-550 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 BRECKSVL OH
— 440-552 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CLEVELAND OH
— 440-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST OH
— 440-556 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 VICTORY OH
— 440-562 not yet reported which blocks → SPOK, INC. 6630 WILLOUGHBY OH
— 440-563 1XXX2XXX6XXX7XXX8XXX · 3 holders which blocks → WINDSTREAM WESTERN RESERVE, INC. 0666 ROCK CREEK OH
— 440-564 not yet reported which blocks → WINDSTREAM WESTERN RESERVE, INC. 0666 NEWBURY OH
— 440-565 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 HILLCREST OH
— 440-567 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 WILLOUGHBY OH
— 440-569 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 WICKLIFFE OH
— 440-570 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 VICTORY OH
— 440-571 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → OHIO BELL TEL CO 9321 WILLOUGHBY OH
— 440-572 not yet reported which blocks → OHIO BELL TEL CO 9321 STRONGSVL OH
— 440-573 3XXX8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 HILLCREST OH
— 440-574 0XXX5XXX6XXX7XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 OBERLIN OH
— 440-575 2XXX3XXX5XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 TRINITY OH
— 440-576 not yet reported which blocks → BRIGHTSPEED OF NORTHWEST OHIO, INC. 0661 JEFFERSON OH
— 440-577 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → WINDSTREAM WESTERN RESERVE, INC. 0666 PIERPONT OH
— 440-578 0XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 MENTOR OH
— 440-579 2XXX3XXX4XXX5XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 PAINESVL OH
— 440-580 1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 STRONGSVL OH
— 440-582 not yet reported which blocks → OHIO BELL TEL CO 9321 NOROYALTON OH
— 440-584 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7443 BRECKSVL OH

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.