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
2026-06-05	406-509	9XXX which blocks →	EXIANT COMMUNICATIONS LLC	114J	MISSOULA	MT
2026-01-15	406-918	1XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	LIBBY	MT
2025-10-09	406-618	0XXX2XXX · 2 holders which blocks →	TDS METROCOM, LLC	520K	MISSOULA	MT
2025-03-18	406-307	1XXX which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	CANYON CRK	MT
2025-01-06	406-610	0–9 XXXall 10 · 5 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	MISSOULA	MT
2024-12-23	406-617	0–9 XXXall 10 · 4 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	BILLINGS	MT
2024-12-18	406-536	0–9 XXXall 10 · 5 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	BOZEMAN	MT
2024-12-09	406-406	0–9 XXXwhole prefix which blocks →	LIVEWIRE TELECOM, LLC	509K	MISSOULA	MT
2024-06-07	406-517	0–9 XXXall 10 · 4 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	LIVINGSTON	MT
2024-01-24	406-997	0XXX1XXX2XXX9XXX · 4 holders which blocks →	AT&T - LOCAL	7421	FROMBERG	MT
2023-12-04	406-955	0–9 XXXall 10 · 4 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	KALISPELL	MT
2023-06-21	406-481	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	MISSOULA	MT
2023-04-27	406-516	0XXX1XXX2XXX8XXX9XXX · 3 holders which blocks →	BOOST SUBSCRIBERCO L.L.C.	490J	LAUREL	MT
2023-04-05	406-503	0–9 XXXall 10 · 4 holders which blocks →	COMCAST IP PHONE, LLC	318J	BILLINGS	MT
2023-02-22	406-512	0XXX1XXX2XXX8XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	BOULDER	MT
2023-02-17	406-507	0XXX1XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	WHITEFISH	MT
2022-09-08	406-405	0–9 XXXall 10 · 4 holders which blocks →	ONVOY, LLC - MT	453F	LIBBY	MT
2022-06-16	406-613	0–9 XXXall 10 · 6 holders which blocks →	CENTURYLINK COMMUNICATIONS, LLC	508J	BOZEMAN	MT
2021-05-24	406-703	0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 7 holders which blocks →	TELNYX LLC	073H	COLUMBUS	MT
2021-05-06	406-608	0–9 XXXall 10 · 3 holders which blocks →	IP HORIZON LLC	515J	BILLINGS	MT
2021-04-22	406-807	0XXX1XXX7XXX8XXX · 3 holders which blocks →	ONVOY, LLC - MT	453F	EGLACIERPK	MT
2021-04-18	406-605	0–9 XXXall 10 · 4 holders which blocks →	TELNYX LLC	073H	BUTTE	MT
2021-04-14	406-901	0–9 XXXall 10 · 4 holders which blocks →	ONVOY SPECTRUM, LLC	624H	BILLINGS	MT
2021-03-24	406-609	0–9 XXXall 10 · 4 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	KALISPELL	MT
2021-02-12	406-504	2XXX which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	FAIRFIELD	MT
2020-10-13	406-614	0–9 XXXall 10 · 5 holders which blocks →	ONVOY, LLC - MT	453F	BIGFORK	MT
2020-07-06	406-341	0–9 XXXall 10 · 2 holders which blocks →	ONVOY, LLC - MT	453F	MANHATTAN	MT
2020-06-17	406-416	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	FORSYTH	MT
2020-06-01	406-506	0–9 XXXall 10 · 4 holders which blocks →	HD CARRIER LLC	321J	BILLINGS	MT
2020-05-12	406-990	0XXX8XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	LAME DEER	MT
2019-10-15	406-408	0XXX which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	HAYS	MT
2019-08-20	406-418	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	COOKE CITY	MT
2019-08-20	406-501	0–9 XXXall 10 · 4 holders which blocks →	ONVOY, LLC - MT	453F	WHITEHALL	MT
2019-08-20	406-804	0–9 XXXall 10 · 4 holders which blocks →	ONVOY, LLC - MT	453F	GARDINER	MT
2019-07-12	406-316	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks →	ONVOY, LLC - MT	453F	BOULDER	MT
2019-07-12	406-419	0XXX1XXX2XXX4XXX5XXX6XXX · 3 holders which blocks →	ONVOY, LLC - MT	453F	VICTOR	MT
2019-05-29	406-401	0–9 XXXall 10 · 3 holders which blocks →	CSC WIRELESS, LLC	425J	GREATFALLS	MT
2019-05-29	406-409	0–9 XXXall 10 · 4 holders which blocks →	CSC WIRELESS, LLC	425J	BILLINGS	MT
2019-03-04	406-919	0–9 XXXall 10 · 4 holders which blocks →	TERRA NOVA TELECOM INC.	145J	BELGRADE	MT
2019-01-29	406-500	0–9 XXXall 10 · 4 holders which blocks →	FRACTEL, LLC	965H	BILLINGS	MT
2018-11-27	406-902	1XXX9XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	SHERIDAN	MT
2018-06-06	406-717	0–9 XXXall 10 · 4 holders which blocks →	VONAGE AMERICA LLC	197D	BILLINGS	MT
2018-05-24	406-909	0–9 XXXall 10 · 6 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	COLUMBIFLS	MT
2017-10-20	406-306	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MT	453F	MANHATTAN	MT
2017-09-29	406-900	0XXX1XXX2XXX4XXX7XXX8XXX9XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MT	9415	ENNIS	MT
2017-09-05	406-308	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT	6564	CASCADE	MT
2017-08-04	406-402	0–9 XXXall 10 · 2 holders which blocks →	T-MOBILE USA, INC.	6529	GREATFALLS	MT
2017-08-02	406-561	0–9 XXXall 10 · 2 holders which blocks →	T-MOBILE USA, INC.	6529	BILLINGS	MT
2017-07-18	406-940	0XXX1XXX5XXX6XXX9XXX · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	MOLT	MT
2017-05-22	406-412	0–9 XXXwhole prefix which blocks →	ONVOY, LLC - MT	453F	BILLINGS	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.