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
2004-07-27	406-371	0–9 XXXall 10 · 5 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	BILLINGS	MT
2004-07-27	406-437	0–9 XXXall 10 · 4 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	HELENA	MT
2004-05-10	406-334	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	LIBBY	MT
2003-11-26	406-396	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	MISSOULA	MT
2003-05-06	406-213	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	COLSTRIP	MT
2003-03-18	406-242	1XXX2XXX5XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	THOMPSNFLS	MT
2003-03-18	406-280	none assigned yet which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	ST REGIS	MT
2003-03-18	406-382	1XXX3XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	SUPERIOR	MT
2003-03-18	406-499	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	SEELEYLAKE	MT
2003-02-13	406-219	0–9 XXXall 10 · 4 holders which blocks →	BANDWIDTH.COM CLEC, LLC - MT	994E	BOZEMAN	MT
2003-02-13	406-221	0–9 XXXall 10 · 6 holders which blocks →	ONVOY, LLC - MT	453F	BUTTE	MT
2003-01-23	406-299	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BUTTE	MT
2003-01-21	406-201	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	FORSYTH	MT
2003-01-20	406-229	2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	CUT BANK	MT
2003-01-09	406-943	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	SIDNEY	MT
2003-01-09	406-944	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	MILES CITY	MT
2003-01-09	406-946	1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	LIVINGSTON	MT
2003-01-09	406-948	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	GLENDIVE	MT
2003-01-09	406-960	none assigned yet which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	DILLON	MT
2003-01-09	406-966	1XXX2XXX3XXX5XXX6XXX7XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	SHELBY	MT
2003-01-09	406-968	6XXX7XXX8XXX9XXX · 2 holders which blocks →	HD CARRIER LLC	321J	LEWISTOWN	MT
2002-07-11	406-346	0XXX which blocks →	RANGE TELEPHONE COOPERATIVE, INC. - MT	8140	FORSYTH	MT
2002-06-19	406-545	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BILLINGS	MT
2002-06-19	406-551	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BOZEMAN	MT
2002-06-19	406-552	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	MISSOULA	MT
2002-06-19	406-558	0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	HELENA	MT
2002-06-19	406-564	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	GREATFALLS	MT
2002-06-19	406-565	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BUTTE	MT
2001-11-12	406-424	0XXX which blocks →	3 RIVERS TELEPHONE COOPERATIVE, INC. - MT	3924	SHELBY	MT
2001-07-12	406-231	7XXX which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	GREATFALLS	MT
2001-04-18	406-202	7XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	HELENA	MT
2001-04-18	406-207	none assigned yet which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	MISSOULA	MT
2001-04-18	406-208	none assigned yet which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	BILLINGS	MT
2001-04-18	406-209	8XXX9XXX which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	BOZEMAN	MT
2001-04-18	406-212	none assigned yet which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	KALISPELL	MT
—	406-203	2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	MISSOULA	MT
—	406-204	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	HELENA	MT
—	406-205	9XXX which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	GREATFALLS	MT
—	406-206	not yet reported which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BILLINGS	MT
—	406-210	6XXX7XXX8XXX which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	SEELEYLAKE	MT
—	406-211	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MT
—	406-214	0–9 XXXall 10 · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	MISSOULA	MT
—	406-215	0–9 XXXall 10 · 5 holders which blocks →	SKYE TELECOM LLC DBA SKYETEL	622J	MISSOULA	MT
—	406-216	0XXX6XXX7XXX · 3 holders which blocks →	3 RIVERS TELEPHONE COOPERATIVE, INC. - MT	3924	GREATFALLS	MT
—	406-217	0–9 XXXwhole prefix which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	GREATFALLS	MT
—	406-220	5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	LIVINGSTON	MT
—	406-222	not yet reported which blocks →	QWEST CORPORATION	9636	LIVINGSTON	MT
—	406-223	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	LIVINGSTON	MT
—	406-224	3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	LIVINGSTON	MT
—	406-225	0XXX1XXX2XXX5XXX6XXX7XXX8XXX · 4 holders which blocks →	QWEST CORPORATION	9636	BOULDER	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.