Recent prefix assignments

5 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, last 30 days — NPA 435

UINTAH BASIN ELECTRONIC TELECOMMUNICATIONS 4

TDS BROADBAND SERVICE LLC 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

Recent NPA-NXX prefix assignments
Assigned	NPA-NXX	Thousands-blocks taken (last-4 opening)	Code holder	OCN	Rate center	State
2003-12-18	435-778	not yet reported which blocks →	UNION TELEPHONE COMPANY	013B	MANILA	UT
2003-12-18	435-779	not yet reported which blocks →	UNION TELEPHONE COMPANY	013B	GARDENCITY	UT
2003-06-03	435-253	3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	FILLMORE	UT
2003-04-24	435-251	0XXX7XXX · 2 holders which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
2003-04-24	435-262	6XXX8XXX · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	FAIRVIEW	UT
2003-03-11	435-252	0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	PARK CITY	UT
2002-12-30	435-275	2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	ST GEORGE	UT
2002-12-30	435-310	2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	BEAVER	UT
2002-11-04	435-494	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	BRIGHAM CY	UT
2002-10-18	435-862	0XXX1XXX2XXX3XXX4XXX5XXX which blocks →	T-MOBILE USA, INC.	6529	ST GEORGE	UT
2002-09-18	435-565	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	PARK CITY	UT
2002-08-22	435-868	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 7 holders which blocks →	QWEST CORPORATION	9636	CEDAR CITY	UT
2002-08-21	435-248	1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	TOOELE	UT
2002-08-13	435-566	not yet reported which blocks →	FIRSTDIGITAL TELECOM, LLC - UT	5727	TOOELE	UT
2002-04-24	435-553	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	BRIGHAM CY	UT
2002-04-24	435-572	0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	CEDAR CITY	UT
2002-04-24	435-612	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	MONROE	UT
2002-04-24	435-633	0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	RICHFIELD	UT
2002-03-07	435-575	not yet reported which blocks →	FIRSTDIGITAL TELECOM, LLC - UT	5727	PARK CITY	UT
2002-02-21	435-580	0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks →	T-MOBILE USA, INC.	6529	NEPHI	UT
2002-01-04	435-333	not yet reported which blocks →	ALL WEST/UTAH, INC.	3881	PARK CITY	UT
2001-12-05	435-538	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM	7176	BRIGHAM CY	UT
2001-10-23	435-562	0–9 XXXall 10 · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	SALINA	UT
2001-10-23	435-571	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	PARK CITY	UT
2001-10-23	435-625	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	BEAVER	UT
2001-10-23	435-710	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	PAROWAN	UT
2001-10-23	435-728	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	TOOELE	UT
2001-10-23	435-767	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	ST GEORGE	UT
2001-10-23	435-856	1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 7 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	NEPHI	UT
2001-10-09	435-785	not yet reported which blocks →	ALL WEST COMMUNICATIONS - UT	2288	TIMBERLAKE	UT
2001-08-17	435-313	not yet reported which blocks →	T-MOBILE USA, INC.	6529	ST GEORGE	UT
2001-08-17	435-327	3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks →	T-MOBILE USA, INC.	6529	CEDAR CITY	UT
2001-06-27	435-224	0XXX1XXX5XXX6XXX7XXX8XXX9XXX which blocks →	T-MOBILE USA, INC.	6529	TOOELE	UT
2001-06-27	435-225	1XXX7XXX8XXX9XXX which blocks →	T-MOBILE USA, INC.	6529	BRIGHAM CY	UT
2001-06-07	435-631	2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	PARK CITY	UT
2001-05-11	435-239	2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks →	T-MOBILE USA, INC.	6529	BRIGHAM CY	UT
2001-05-02	435-336	not yet reported which blocks →	ALL WEST COMMUNICATIONS - UT	2288	COALVILLE	UT
2001-04-27	435-233	2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	CEDAR CITY	UT
2001-04-27	435-558	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	RICHFIELD	UT
2001-04-13	435-226	2XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks →	PAETEC ITEL, LLC	829J	BRIGHAM CY	UT
2001-04-13	435-227	3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks →	PAETEC ITEL, LLC	829J	LOGAN	UT
2001-04-13	435-228	2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	PAETEC ITEL, LLC	829J	TOOELE	UT
2001-02-07	435-235	not yet reported which blocks →	SPOK, INC.	6630	CEDAR CITY	UT
2001-02-02	435-204	not yet reported which blocks →	SPOK, INC.	6630	TOOELE	UT
—	435-200	1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks →	ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM	7176	PARK CITY	UT
—	435-201	5XXX6XXX7XXX8XXX · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	RICHFIELD	UT
—	435-203	6XXX7XXX which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	MTPLEASANT	UT
—	435-207	not yet reported which blocks →	CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT	4429	TREMONTON	UT
—	435-208	not yet reported which blocks →				UT
—	435-210	1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	MOAB	UT

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.