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 586
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 132
MICHIGAN BELL TEL CO 100
NEW CINGULAR WIRELESS PCS, LLC - IL 60
OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 43
AMERICAN MESSAGING SERVICES, LLC 27
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
— 586-269 not yet reported which blocks → MI
— 586-270 1XXX2XXX3XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEW HAVEN MI
— 586-273 2XXX3XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEWBALTIMR MI
— 586-274 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 WARREN MI
— 586-276 5XXX7XXX9XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 WARREN MI
— 586-279 9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 ROSEVILLE MI
— 586-283 9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 WARREN MI
— 586-285 5XXX which blocks → MICHIGAN BELL TEL CO 9323 ROSEVILLE MI
— 586-286 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 MT CLEMENS MI
— 586-292 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
— 586-293 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 ROSEVILLE MI
— 586-294 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 ROSEVILLE MI
— 586-295 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
— 586-296 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 ROSEVILLE MI
— 586-303 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLCV - MI 543C WARREN MI
— 586-306 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WARREN MI
— 586-307 2XXX4XXX5XXX6XXX · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 MT CLEMENS MI
— 586-308 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 ROSEVILLE MI
— 586-309 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 ROSEVILLE MI
— 586-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MI
— 586-313 not yet reported which blocks → MI
— 586-314 none assigned yet which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 UTICA MI
— 586-317 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J RICHMOND MI
— 586-319 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 WARREN MI
— 586-321 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MT CLEMENS MI
— 586-322 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MT CLEMENS MI
— 586-323 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 UTICA MI
— 586-327 0–9 XXXwhole prefix which blocks → ONVOY, LLCV - MI 543C ROSEVILLE MI
— 586-330 0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E NEWBALTIMR MI
— 586-331 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E ROMEO MI
— 586-336 8XXX which blocks → MICHIGAN BELL TEL CO 9323 ROMEO MI
— 586-337 7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ROMEO MI
— 586-339 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 NEW HAVEN MI
— 586-344 not yet reported which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 WARREN MI
— 586-349 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MT CLEMENS MI
— 586-350 0XXX2XXX · 2 holders which blocks → METROPCS, INC. 5562 ROSEVILLE MI
— 586-353 5XXX8XXX which blocks → PAETEC ITEL, LLC 829J CENTERLINE MI
— 586-354 0–9 XXXall 10 · 3 holders which blocks → 123.NET, LLC 2550 WARREN MI
— 586-360 0XXX1XXX2XXX9XXX · 4 holders which blocks → METROPCS, INC. 5562 ROSEVILLE MI
— 586-361 not yet reported which blocks → SPOK, INC. 6630 ROMEO MI
— 586-362 0XXX1XXX2XXX3XXX7XXX8XXX9XXX · 6 holders which blocks → METROPCS, INC. 5562 ROSEVILLE MI
— 586-363 not yet reported which blocks → SPOK, INC. 6630 MT CLEMENS MI
— 586-372 0–9 XXXall 10 · 6 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ROMEO MI
— 586-380 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 ROMEO MI
— 586-381 5XXX7XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WARREN MI
— 586-382 9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WARREN MI
— 586-383 9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WARREN MI
— 586-393 0XXX2XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → AT&T ENTERPRISES, LLC 516C CENTERLINE MI
— 586-402 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 WARREN MI
— 586-403 not yet reported which blocks → SPOK, INC. 6630 MT CLEMENS MI

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.