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 661
PACIFIC BELL 145
PACIFIC BELL (COMPETITIVE) 1
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
— 661-665 6XXX which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-702 4XXX which blocks → PACIFIC BELL 9740 SNCA NHCS CA
— 661-720 1XXX3XXX6XXX · 2 holders which blocks → PACIFIC BELL 9740 DELANO CA
— 661-721 not yet reported which blocks → PACIFIC BELL 9740 DELANO CA
— 661-725 not yet reported which blocks → PACIFIC BELL 9740 DELANO CA
— 661-746 not yet reported which blocks → PACIFIC BELL 9740 SHAFTER CA
— 661-753 3XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → PACIFIC BELL 9740 SNCA NHCS CA
— 661-758 not yet reported which blocks → PACIFIC BELL 9740 WASCO CA
— 661-775 not yet reported which blocks → PACIFIC BELL 9740 SNCA NHCS CA
— 661-789 7XXX8XXX · 2 holders which blocks → PACIFIC BELL 9740 PLDL PLDL CA
— 661-799 not yet reported which blocks → PACIFIC BELL 9740 SNCA NHCS CA
— 661-808 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-817 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-821 8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 TEHACHAPI CA
— 661-822 not yet reported which blocks → PACIFIC BELL 9740 TEHACHAPI CA
— 661-823 4XXX which blocks → PACIFIC BELL 9740 TEHACHAPI CA
— 661-824 not yet reported which blocks → PACIFIC BELL 9740 MOJAVE CA
— 661-827 2XXX6XXX7XXX · 3 holders which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-831 not yet reported which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-832 not yet reported which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-833 not yet reported which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-834 not yet reported which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-835 6XXX which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-836 5XXX7XXX · 2 holders which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-837 not yet reported which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-842 not yet reported which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-845 not yet reported which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-849 0XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 EARLIMART CA
— 661-852 1XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-854 9XXX which blocks → PACIFIC BELL 9740 ARVIN CA
— 661-855 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 ARVIN CA
— 661-858 3XXX4XXX6XXX7XXX8XXX9XXX which blocks → PACIFIC BELL 9740 BKFD SOUTH CA
— 661-859 3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-861 3XXX which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-862 0XXX1XXX2XXX3XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-863 1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-864 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-867 5XXX which blocks → PACIFIC BELL 9740 WALKERBSIN CA
— 661-868 9XXX which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-869 0XXX4XXX5XXX7XXX which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-871 not yet reported which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-872 not yet reported which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-873 3XXX4XXX5XXX · 3 holders which blocks → PACIFIC BELL 9740 BKFD MAIN CA
— 661-944 7XXX which blocks → PACIFIC BELL 9740 PLDL PLDL CA
— 661-947 not yet reported which blocks → PACIFIC BELL 9740 PLDL PLDL CA
— 661-974 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL (COMPETITIVE) 7480 LANCASTER 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.