NumberResearch Membership · Data 09/27/2026

Recent prefix assignments

341 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/27/2026

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 26
Rogers Communications Canada Inc. (Wireless) 23
NEW CINGULAR WIRELESS PCS, LLC - IL 22
ONVOY, LLC - CA 21
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
— 623-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST AZ
— 623-556 3XXX6XXX7XXX which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-561 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-562 0–9 XXXall 10 · 3 holders which blocks → COMCAST IP PHONE, LLC 318J PHOENIX AZ
— 623-566 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-570 not yet reported which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
— 623-572 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-580 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-581 4XXX which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-582 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-583 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-584 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-587 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-594 not yet reported which blocks → COMCAST IP PHONE, LLC 318J PHOENIX AZ
— 623-606 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PHOENIX AZ
— 623-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AZ
— 623-628 not yet reported which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
— 623-640 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-643 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-670 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-680 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-683 0–9 XXXwhole prefix which blocks → COMCAST IP PHONE, LLC 318J PHOENIX AZ
— 623-687 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
— 623-688 0XXX1XXX2XXX3XXX5XXX8XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-691 7XXX8XXX which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-694 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-695 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-700 not yet reported which blocks → AZ
— 623-703 5XXX8XXX which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
— 623-707 3XXX5XXX6XXX7XXX8XXX9XXX which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - AZ 7217 PHOENIX AZ
— 623-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AZ
— 623-734 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
— 623-742 1XXX2XXX3XXX5XXX8XXX · 2 holders which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-760 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - AZ 7217 PHOENIX AZ
— 623-764 9XXX which blocks → METROPCS, INC. 5562 PHOENIX AZ
— 623-772 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-773 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-776 5XXX6XXX which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-780 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-792 0XXX3XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 TELECOM OF ARIZONA, LLC - AZ 7552 PHOENIX AZ
— 623-810 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
— 623-811 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AZ
— 623-815 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-824 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - AZ 7217 PHOENIX AZ
— 623-825 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-842 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-845 2XXX which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-846 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-847 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ
— 623-848 not yet reported which blocks → QWEST CORPORATION 9636 PHOENIX AZ

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/27/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.