NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

355 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
8X8, INC. 38
ONVOY, LLC - CA 31
NEW CINGULAR WIRELESS PCS, LLC - IL 28
NEW CINGULAR WIRELESS PCS, LLC - DC 26
ONVOY, LLC - NJ 18
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 — who really holds the numbersCode holderOCNRate centerState
— 231-494 Not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 BIG RAPIDS MI
— 231-497 10 of 10 blocks assigned · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BOYNE CITY MI
— 231-499 Not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TRAVERSECY MI
— 231-510 Not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI
— 231-511 Not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MI
— 231-512 Not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 TRAVERSECY MI
— 231-514 Not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CADILLAC MI
— 231-516 Not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 PETOSKEY MI
— 231-517 Not yet reported which blocks → MI
— 231-522 Not yet reported which blocks → 123.NET, LLC 2550 LUTHER MI
— 231-525 7 of 10 blocks assigned · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 WOLVERINE MI
— 231-526 Not yet reported which blocks → MICHIGAN BELL TEL CO 9323 HARBOR SPG MI
— 231-527 5 of 10 blocks assigned · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 BIG RAPIDS MI
— 231-529 3 of 10 blocks assigned · 3 holders which blocks → BRIGHTSPEED OF MICHIGAN, LLC 0702 BRUTUS MI
— 231-533 3 of 10 blocks assigned · 2 holders which blocks → FRONTIER NORTH, INC. - MI 0695 BELLAIRE MI
— 231-535 7 of 10 blocks assigned · 7 holders which blocks → MICHIGAN BELL TEL CO 9323 WALLOON LK MI
— 231-536 3 of 10 blocks assigned · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 EASTJORDAN MI
— 231-537 Not yet reported which blocks → BRIGHTSPEED OF MICHIGAN, LLC 0702 LEVERING MI
— 231-539 8 of 10 blocks assigned · 7 holders which blocks → MICHIGAN BELL TEL CO 9323 PELLSTON MI
— 231-544 3 of 10 blocks assigned · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 CENTRAL LK MI
— 231-546 Not yet reported which blocks → BRIGHTSPEED OF MICHIGAN, LLC 0702 ELMIRA MI
— 231-547 Not yet reported which blocks → MICHIGAN BELL TEL CO 9323 CHARLEVOIX MI
— 231-548 Not yet reported which blocks → BRIGHTSPEED OF MICHIGAN, LLC 0702 ALANSON MI
— 231-549 1 of 10 blocks assigned · 1 holder which blocks → BRIGHTSPEED OF MICHIGAN, LLC 0702 BOYNEFALLS MI
— 231-555 Not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MI
— 231-557 Not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MUSKEGON MI
— 231-563 10 of 10 blocks assigned · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
— 231-564 7 of 10 blocks assigned · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KALKASKA MI
— 231-568 Not yet reported which blocks → 123.NET, LLC 2550 TRAVERSECY MI
— 231-569 Not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 PETOSKEY MI
— 231-571 9 of 10 blocks assigned · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-578 0 of 10 blocks assigned · 0 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
— 231-582 Not yet reported which blocks → MICHIGAN BELL TEL CO 9323 BOYNE CITY MI
— 231-584 Not yet reported which blocks → PIGEON TEL. CO. 0721 ALBA MI
— 231-585 Not yet reported which blocks → PIGEON TEL. CO. 0721 LAKE NORTH MI
— 231-586 Not yet reported which blocks → MI
— 231-587 3 of 10 blocks assigned · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 MANCELONA MI
— 231-588 6 of 10 blocks assigned · 4 holders which blocks → FRONTIER NORTH, INC. - MI 0695 ELLSWORTH MI
— 231-590 Not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TRAVERSECY MI
— 231-591 Not yet reported which blocks → MICHIGAN BELL TEL CO 9323 BIG RAPIDS MI
— 231-592 Not yet reported which blocks → MICHIGAN BELL TEL CO 9323 BIG RAPIDS MI
— 231-593 Not yet reported which blocks → SPOK, INC. 6630 CADILLAC MI
— 231-594 10 of 10 blocks assigned · 5 holders which blocks → TWILIO INTERNATIONAL, INC. 506J HART MI
— 231-596 Not yet reported which blocks → SPOK, INC. 6630 HARBOR SPG MI
— 231-597 5 of 10 blocks assigned · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 CHEBOYGAN MI
— 231-598 6 of 10 blocks assigned · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BIG RAPIDS MI
— 231-599 8 of 10 blocks assigned · 4 holders which blocks → FRONTIER NORTH, INC. - MI 0695 EASTPORT MI
— 231-604 Not yet reported which blocks → SPOK, INC. 6630 KALKASKA MI
— 231-605 Not yet reported which blocks → SPOK, INC. 6630 NEWAYGO MI
— 231-608 Not yet reported which blocks → SPOK, INC. 6630 FRANKFORT MI

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.