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 323
PACIFIC BELL 265
METROPCS NETWORKS, LLC 85
T-MOBILE USA, INC. 64
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 45
NEW CINGULAR WIRELESS PCS, LLC 39
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
— 323-562 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-563 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-564 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-565 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-566 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-567 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-568 0XXX1XXX6XXX7XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-569 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-571 4XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → METROPCS NETWORKS, LLC 899D LSAN DA 13 CA
— 323-572 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → METROPCS NETWORKS, LLC 899D LSAN DA 14 CA
— 323-573 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 LSAN DA 14 CA
— 323-574 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 LSAN DA 14 CA
— 323-575 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-576 2XXX4XXX · 2 holders which blocks → ONVOY, LLC - CA 649C LSAN DA 04 CA
— 323-577 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 TELECOM OF CALIFORNIA, LP - CA 7718 LSAN DA 04 CA
— 323-578 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 LSAN DA 14 CA
— 323-579 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 02 CA
— 323-580 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 LSAN DA 14 CA
— 323-581 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-582 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-583 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-584 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-585 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-586 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-587 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-588 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-589 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-596 0XXX1XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J LSAN DA 12 CA
— 323-599 0–9 XXXall 10 · 3 holders which blocks → UTILITY TELECOM GROUP, LLC - CA 9262 LSAN DA 09 CA
— 323-600 3XXX4XXX5XXX7XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-604 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-605 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-606 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 14 CA
— 323-609 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 08 CA
— 323-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX CA
— 323-618 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F LSAN DA 02 CA
— 323-619 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-622 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MONTEBELLO CA
— 323-623 not yet reported which blocks → NORTH COUNTY COMMUNICATION CORPORATION - CA 7894 LSAN DA 14 CA
— 323-624 not yet reported which blocks → NORTH COUNTY COMMUNICATION CORPORATION - CA 7894 MONTEBELLO CA
— 323-625 not yet reported which blocks → NORTH COUNTY COMMUNICATION CORPORATION - CA 7894 LSAN DA 06 CA
— 323-626 not yet reported which blocks → NORTH COUNTY COMMUNICATION CORPORATION - CA 7894 MONTEBELLO CA
— 323-633 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 LSAN DA 09 CA
— 323-634 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-635 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 TELECOM OF CALIFORNIA, LP - CA 7718 LSAN DA 02 CA
— 323-636 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-638 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 LSAN DA 06 CA
— 323-639 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - CA 649C LSAN DA 11 CA
— 323-643 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PACIFIC BELL 9740 LSAN DA 11 CA
— 323-644 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 02 CA

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.