NumberResearch Membership · Data 09/30/2026

Recent prefix assignments

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

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
Rogers Communications Canada Inc. (Wireless) 46
8X8, INC. 43
NEW CINGULAR WIRELESS PCS, LLC - DC 27
NEW CINGULAR WIRELESS PCS, LLC - IL 23
ONVOY, LLC - CA 19
New assignments by month Oct 2026 Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 517-552 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 HOWELL MI
— 517-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MI
— 517-563 not yet reported which blocks → FRONTIER COMMUNICATIONS OF MICHIGAN, INC. 4417 HANOVER MI
— 517-564 not yet reported which blocks → SPOK, INC. 6630 ADRIAN MI
— 517-565 0XXX2XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → FRONTIER MIDSTATES, INC. - MI 0681 FITCHBURG MI
— 517-566 0XXX1XXX2XXX3XXX4XXX6XXX9XXX · 4 holders which blocks → BRIGHTSPEED OF CENTRAL MICHIGAN, INC 0671 SUNFIELD MI
— 517-567 not yet reported which blocks → FRONTIER COMMUNICATIONS OF MICHIGAN, INC. 4417 RANSOM MI
— 517-568 0XXX1XXX2XXX8XXX9XXX · 4 holders which blocks → FRONTIER MIDSTATES, INC. - MI 0681 HOMER MI
— 517-569 0XXX1XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → FRONTIER MIDSTATES, INC. - MI 0681 RIVES JCT MI
— 517-571 not yet reported which blocks → SPOK, INC. 6630 HOWELL MI
— 517-575 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 LANSING MI
— 517-577 0–9 XXXall 10 · 2 holders which blocks → COMCAST IP PHONE, LLC 318J ADRIAN MI
— 517-579 1XXX2XXX3XXX5XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 HOWELL MI
— 517-580 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 LANSING MI
— 517-581 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 JACKSON MI
— 517-582 2XXX6XXX7XXX9XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 LANSING MI
— 517-586 3XXX which blocks → PAETEC ITEL, LLC 829J HOWELL MI
— 517-589 1XXX4XXX6XXX7XXX · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 LESLIE MI
— 517-592 not yet reported which blocks → FRONTIER COMMUNICATIONS OF MICHIGAN, INC. 4417 BROOKLYN MI
— 517-596 0XXX1XXX4XXX5XXX6XXX9XXX · 3 holders which blocks → FRONTIER MIDSTATES, INC. - MI 0681 MUNITH MI
— 517-599 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 LANSING MI
— 517-605 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ADRIAN MI
— 517-606 not yet reported which blocks → TC3 TELECOM, INC. - MI 3459 BLISSFIELD MI
— 517-607 0XXX1XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 HILLSDALE MI
— 517-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MI
— 517-617 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 COLDWATER MI
— 517-618 1XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 HOWELL MI
— 517-622 9XXX which blocks → FRONTIER NORTH, INC. - MI 0695 GRANDLEDGE MI
— 517-623 2XXX3XXX4XXX5XXX7XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 DANSVILLE MI
— 517-625 2XXX9XXX which blocks → SHIAWASSEE TEL. CO. 0726 PERRY MI
— 517-626 0XXX1XXX3XXX4XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - MI 0695 GRANDLEDGE MI
— 517-627 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 GRANDLEDGE MI
— 517-628 0XXX1XXX4XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → FRONTIER MIDSTATES, INC. - MI 0681 ONONDAGA MI
— 517-629 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 ALBION MI
— 517-630 1XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 ALBION MI
— 517-639 0XXX1XXX2XXX6XXX · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 QUINCY MI
— 517-641 0XXX1XXX2XXX3XXX5XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - MI 0695 BATH MI
— 517-645 3XXX5XXX6XXX8XXX · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 POTTERVL MI
— 517-646 1XXX4XXX · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 DIMONDALE MI
— 517-647 3XXX9XXX which blocks → MICHIGAN BELL TEL CO 9323 PORTLAND MI
— 517-648 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 LANSING MI
— 517-649 0XXX1XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 MULLIKEN MI
— 517-651 0XXX4XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 LAINGSBURG MI
— 517-655 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 WILLIAMSTN MI
— 517-657 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J LANSING MI
— 517-663 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 EATON RPD MI
— 517-664 0XXX3XXX9XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 LANSING MI
— 517-668 4XXX5XXX6XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - MI 0695 DE WITT MI
— 517-669 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 DE WITT MI
— 517-675 8XXX9XXX which blocks → SHIAWASSEE TEL. CO. 0726 SHAFTSBURG MI

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/30/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.