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
— 323-931 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-932 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-933 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-934 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-935 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-936 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-937 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-938 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-939 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-940 1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 04 CA
— 323-942 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 09 CA
— 323-943 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 05 CA
— 323-944 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-945 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 TELECOM OF CALIFORNIA, LP - CA 7718 MONTEBELLO CA
— 323-947 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-948 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 05 CA
— 323-950 not yet reported which blocks → MULTIPLE OCN LISTING MULT CA
— 323-951 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-953 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 02 CA
— 323-954 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-956 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-957 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-958 not yet reported which blocks → CA
— 323-959 not yet reported which blocks → CA
— 323-960 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-962 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-964 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-965 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-966 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-967 1XXX3XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 09 CA
— 323-969 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-971 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-972 none assigned yet which blocks → METROPCS NETWORKS, LLC 899D MONTEBELLO CA
— 323-973 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7139 LSAN DA 06 CA
— 323-974 none assigned yet which blocks → T-MOBILE USA, INC. 6529 LSAN DA 12 CA
— 323-977 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 09 CA
— 323-978 3XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 14 CA
— 323-979 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-980 6XXX which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-981 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-982 3XXX5XXX7XXX8XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-983 1XXX3XXX6XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LSAN DA 06 CA
— 323-985 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 08 CA
— 323-987 0XXX3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J LSAN DA 04 CA
— 323-988 2XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 LSAN DA 13 CA
— 323-992 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 LSAN DA 09 CA
— 323-993 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-995 1XXX which blocks → UTILITY TELECOM GROUP, LLC - CA 9262 LSAN DA 13 CA
— 323-998 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7139 LSAN DA 11 CA
— 323-999 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J LSAN DA 03 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.