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

Recent NPA-NXX prefix assignments
Assigned	NPA-NXX	Thousands-blocks taken (last-4 opening)	Code holder	OCN	Rate center	State
2010-08-16	406-407	0–9 XXXall 10 · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	KALISPELL	MT
2010-07-23	406-927	0–9 XXXall 10 · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	BILLINGS	MT
2010-04-09	406-415	0–9 XXXall 10 · 6 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	DEER LODGE	MT
2009-11-11	406-879	0–9 XXXall 10 · 5 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	HAVRE	MT
2009-10-23	406-942	0XXX1XXX2XXX · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	GLASGOW	MT
2009-03-20	406-898	0–9 XXXall 10 · 4 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	BOZEMAN	MT
2008-10-27	406-845	0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	CUT BANK	MT
2008-08-26	406-992	0XXX which blocks →	ONVOY, LLC - MT	453F	HELENA	MT
2008-07-03	406-647	0–9 XXXall 10 · 2 holders which blocks →	BANDWIDTH.COM CLEC, LLC - MT	994E	BILLINGS	MT
2008-05-28	406-417	0–9 XXXall 10 · 6 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	HELENA	MT
2008-05-06	406-301	0XXX1XXX2XXX3XXX4XXX5XXX8XXX · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	MALTA	MT
2008-04-08	406-513	1XXX8XXX9XXX · 2 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	HELENA	MT
2007-10-15	406-872	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks →	WESTERN MONTANA COMMUNITYTEL INC. - MT	986F	POLSON	MT
2007-10-11	406-612	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	ONVOY, LLC - MT	453F	SWAN LAKE	MT
2007-10-11	406-692	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	YELLOW BAY	MT
2007-10-11	406-820	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	OLNEY	MT
2007-10-11	406-991	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	ONVOY, LLC - MT	453F	MARION	MT
2007-07-26	406-631	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	ELMO	MT
2007-07-26	406-929	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	HUNGRYHORS	MT
2007-05-24	406-643	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	NO PARKMAN	MT
2007-05-23	406-840	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks →	ONVOY, LLC - MT	453F	SILVERTIP	MT
2007-03-14	406-290	0–9 XXXall 10 · 6 holders which blocks →	ONVOY, LLC - MT	453F	COLUMBUS	MT
2007-02-06	406-830	0–9 XXXall 10 · 4 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	MISSOULA	MT
2006-09-30	406-839	0–9 XXXall 10 · 2 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	BILLINGS	MT
2006-09-08	406-743	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	LAUREL	MT
2006-07-11	406-999	not yet reported which blocks →	MONTANA OPTICOM, LLC - MT	746D	BIG SKY	MT
2006-06-15	406-696	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	BILLINGS	MT
2006-06-15	406-871	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	KALISPELL	MT
2006-04-13	406-600	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	BOZEMAN	MT
2006-03-30	406-393	0–9 XXXall 10 · 3 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	SOMERS	MT
2006-03-15	406-794	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	BILLINGS	MT
2006-03-08	406-403	0–9 XXXall 10 · 2 holders which blocks →	ONVOY, LLC - MT	453F	GREATFALLS	MT
2006-02-28	406-420	0–9 XXXall 10 · 3 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	BIGFORK	MT
2005-12-06	406-620	not yet reported which blocks →	SAGEBRUSH CELLULAR, INC.	443B	BILLINGS	MT
2005-09-16	406-529	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	MISSOULA	MT
2005-08-22	406-750	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	GREATFALLS	MT
2005-07-01	406-440	2XXX5XXX6XXX7XXX · 3 holders which blocks →	3 RIVERS TELEPHONE COOPERATIVE, INC. - MT	3924	HELENA	MT
2005-06-01	406-471	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	KALISPELL	MT
2005-04-21	406-697	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	BILLINGS	MT
2005-02-16	406-630	0–9 XXXall 10 · 6 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	SIDNEY	MT
2005-02-16	406-708	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks →	WIDE VOICE, LLC - MT	743G	LEWISTOWN	MT
2005-02-03	406-624	0–9 XXXall 10 · 6 holders which blocks →	MONTANA OPTICOM, LLC - MT	746D	BOZEMAN	MT
2005-01-10	406-680	0XXX2XXX · 2 holders which blocks →	SAGEBRUSH CELLULAR, INC.	443B	MALTA	MT
2005-01-07	406-988	0XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	DILLON	MT
2005-01-05	406-694	0–9 XXXall 10 · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	BILLINGS	MT
2004-10-26	406-599	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	BOZEMAN	MT
2004-10-26	406-924	0–9 XXXall 10 · 6 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BELGRADE	MT
2004-10-21	406-314	0–9 XXXall 10 · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	KALISPELL	MT
2004-08-04	406-451	0–9 XXXall 10 · 3 holders which blocks →	T-MOBILE USA, INC.	6529	BOZEMAN	MT
2004-08-03	406-218	0–9 XXXall 10 · 6 holders which blocks →	T-MOBILE USA, INC.	6529	MISSOULA	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.