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
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
— 323-838 not yet reported which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-845 2XXX5XXX which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-846 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 08 CA
— 323-848 4XXX which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-849 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-850 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-851 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-852 2XXX3XXX4XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-856 1XXX which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-857 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-860 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-862 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-866 0XXX4XXX5XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-869 not yet reported which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-870 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PACIFIC BELL 9740 LSAN DA 11 CA
— 323-871 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-872 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-873 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-874 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-875 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-876 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-877 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-878 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-879 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-881 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-882 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-883 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-887 not yet reported which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-888 not yet reported which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-889 9XXX which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-890 6XXX which blocks → PACIFIC BELL 9740 MONTEBELLO CA
— 323-898 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-900 0XXX5XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-906 4XXX5XXX6XXX7XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 02 CA
— 323-912 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 02 CA
— 323-913 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 02 CA
— 323-930 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 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
— 323-944 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-947 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 MONTEBELLO 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

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.