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 406
QWEST CORPORATION 132
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 119
NEW CINGULAR WIRELESS PCS, LLC 74
ONVOY, LLC - MT 43
TRIANGLE TEL. COOP. ASSN., INC. 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
— 406-557 1XXX3XXX7XXX · 3 holders which blocks → MID-RIVERS TEL. COOP., INC. 2246 JORDAN MT
— 406-559 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 ANACONDA MT
— 406-560 9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 ANACONDA MT
— 406-562 not yet reported which blocks → 3 RIVERS TEL. COOP., INC. 2255 AUGUSTA MT
— 406-563 0XXX which blocks → QWEST CORPORATION 9636 ANACONDA MT
— 406-566 7XXX which blocks → TRIANGLE TEL. COOP. ASSN., INC. 3310 STANFORD MT
— 406-567 not yet reported which blocks → TRIANGLE TEL. COOP. ASSN., INC. 3310 DENTON MT
— 406-568 4XXX which blocks → MID-RIVERS TEL. COOP., INC. 2246 RYEGATE MT
— 406-569 not yet reported which blocks → RESERVATION TEL. COOP. 1632 WSQUAW GAP MT
— 406-570 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 BOZEMAN MT
— 406-571 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → CHARTER IP ENABLED SERVICES, LLC 792K FINLEY PT MT
— 406-572 not yet reported which blocks → TRIANGLE TEL. COOP. ASSN., INC. 3310 MARTINSDL MT
— 406-573 0XXX1XXX6XXX8XXX · 3 holders which blocks → SIYEH COMMUNICATIONS 619J BROWNING MT
— 406-574 0XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → QWEST CORPORATION 9636 SILVERTIP MT
— 406-575 not yet reported which blocks → MID-RIVERS TEL. COOP., INC. 2246 NO RYEGATE MT
— 406-576 1XXX7XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 CONRAD MT
— 406-577 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → ONVOY, LLC - MT 453F BOZEMAN MT
— 406-578 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → QWEST CORPORATION 9636 WILSALL MT
— 406-579 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 BOZEMAN MT
— 406-580 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 BOZEMAN MT
— 406-581 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 BOZEMAN MT
— 406-582 not yet reported which blocks → QWEST CORPORATION 9636 BOZEMAN MT
— 406-583 not yet reported which blocks → MID-RIVERS TEL. COOP., INC. 2246 BLOOMFIELD MT
— 406-584 none assigned yet which blocks → MID-RIVERS TEL. COOP., INC. 2246 LINDSAY MT
— 406-585 not yet reported which blocks → QWEST CORPORATION 9636 BOZEMAN MT
— 406-586 not yet reported which blocks → QWEST CORPORATION 9636 BOZEMAN MT
— 406-587 not yet reported which blocks → QWEST CORPORATION 9636 BOZEMAN MT
— 406-588 not yet reported which blocks → MID-RIVERS TEL. COOP., INC. 2246 CARLYLE MT
— 406-589 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 BOZEMAN MT
— 406-590 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 GREATFALLS MT
— 406-591 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 BILLINGS MT
— 406-592 none assigned yet which blocks → RANGE TEL COOP INC 2251 BUSBY MT
— 406-593 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 BUTTE MT
— 406-594 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 HELENA MT
— 406-595 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 BOZEMAN MT
— 406-596 none assigned yet which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 DILLON MT
— 406-597 6XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SHELBY MT
— 406-598 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 BILLINGS MT
— 406-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MT
— 406-621 0XXX1XXX2XXX5XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 FORTBENTON MT
— 406-622 8XXX9XXX · 2 holders which blocks → TRIANGLE TEL. COOP. ASSN., INC. 3310 FORTBENTON MT
— 406-623 0–9 XXXall 10 · 8 holders which blocks → COMMIO, LLC 939H HARDIN MT
— 406-625 0–9 XXXall 10 · 6 holders which blocks → AT&T - LOCAL 7421 STEVENSVL MT
— 406-626 3XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9636 FRENCHTOWN MT
— 406-627 not yet reported which blocks → 3 RIVERS TEL. COOP., INC. 2255 EASTCONRAD MT
— 406-628 0XXX which blocks → QWEST CORPORATION 9636 LAUREL MT
— 406-629 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ONVOY, LLC - MT 453F HARDIN MT
— 406-632 8XXX which blocks → TRIANGLE TEL. COOP. ASSN., INC. 3310 HARLOWTON MT
— 406-633 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → QWEST CORPORATION 9636 LAUREL MT
— 406-634 3XXX4XXX5XXX · 2 holders which blocks → ONVOY, LLC - MT 453F HELENA MT

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.