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
—	435-554	0–9 XXXall 10 · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - UT	3231	LOGAN	UT
—	435-555	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	DIR ASST	UT
—	435-559	none assigned yet which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	CEDAR CITY	UT
—	435-563	not yet reported which blocks →	QWEST CORPORATION	9636	LOGAN	UT
—	435-564	not yet reported which blocks →	EMERY TELEPHONE DBA EMERY TELCOM	2278	GREENRIVER	UT
—	435-574	1XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
—	435-577	not yet reported which blocks →	SOUTH CENTRAL UTAH TEL. ASSN., INC.	2286	CIRCLEVL	UT
—	435-578	not yet reported which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	TOOELE	UT
—	435-579	5XXX6XXX · 2 holders which blocks →	XO UTAH, INC.	7541	TOOELE	UT
—	435-586	not yet reported which blocks →	QWEST CORPORATION	9636	CEDAR CITY	UT
—	435-587	not yet reported which blocks →	CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT	4429	MONTICELLO	UT
—	435-590	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	CEDAR CITY	UT
—	435-592	1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	CEDAR CITY	UT
—	435-602	1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	T-MOBILE USA, INC.	6529	PARK CITY	UT
—	435-604	5XXX which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - UT	7530	PARK CITY	UT
—	435-608	not yet reported which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	PARK CITY	UT
—	435-609	1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	CASTLEDALE	UT
—	435-610	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	NEPHI	UT
—	435-611	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	UT
—	435-613	not yet reported which blocks →	CARBON/EMERY TELCOM, INC. - UT	1190	PRICE	UT
—	435-615	not yet reported which blocks →	QWEST CORPORATION	9636	PARK CITY	UT
—	435-616	not yet reported which blocks →	SOUTH CENTRAL UTAH TEL. ASSN., INC.	2286	PANGUITCH	UT
—	435-618	1XXX9XXX · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	PANGUITCH	UT
—	435-619	8XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC	6010	ST GEORGE	UT
—	435-622	none assigned yet which blocks →	UBTA-UBET COMMUNICATIONS, INC. DBA STRATA NETWORKS	2287	FLATTOP	UT
—	435-623	none assigned yet which blocks →	QWEST CORPORATION	9636	NEPHI	UT
—	435-624	not yet reported which blocks →	SOUTH CENTRAL UTAH TEL. ASSN., INC.	2286	ANTIMONY	UT
—	435-627	3XXX5XXX6XXX7XXX · 4 holders which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
—	435-628	not yet reported which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
—	435-630	2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	PRICE	UT
—	435-632	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	ST GEORGE	UT
—	435-634	not yet reported which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
—	435-635	not yet reported which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
—	435-636	not yet reported which blocks →	CARBON/EMERY TELCOM, INC. - UT	1190	PRICE	UT
—	435-637	not yet reported which blocks →	CARBON/EMERY TELCOM, INC. - UT	1190	PRICE	UT
—	435-638	not yet reported which blocks →	SOUTH CENTRAL UTAH TEL. ASSN., INC.	2286	KOOSHAREM	UT
—	435-640	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	PARK CITY	UT
—	435-642	not yet reported which blocks →	UNION TEL. CO.	2297	CHRISTMMDW	UT
—	435-644	not yet reported which blocks →	SOUTH CENTRAL UTAH TEL. ASSN., INC.	2286	KANAB	UT
—	435-645	not yet reported which blocks →	QWEST CORPORATION	9636	PARK CITY	UT
—	435-646	not yet reported which blocks →	UBTA-UBET COMMUNICATIONS, INC. DBA STRATA NETWORKS	2287	FLATTOP	UT
—	435-647	none assigned yet which blocks →	QWEST CORPORATION	9636	PARK CITY	UT
—	435-648	not yet reported which blocks →	SOUTH CENTRAL UTAH TEL. ASSN., INC.	2286	ORDERVILLE	UT
—	435-649	not yet reported which blocks →	QWEST CORPORATION	9636	PARK CITY	UT
—	435-650	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	PRICE	UT
—	435-651	not yet reported which blocks →	NAVAJO COMM CO INC - UT DBA NAVAJO COMM UT	4451	MNZMCRANTH	UT
—	435-652	not yet reported which blocks →	QWEST CORPORATION	9636	ST GEORGE	UT
—	435-653	not yet reported which blocks →	EMERY TELEPHONE DBA EMERY TELCOM	2278	CASTLEDALE	UT
—	435-654	none assigned yet which blocks →	QWEST CORPORATION	9636	HEBER CITY	UT
—	435-655	none assigned yet which blocks →	QWEST CORPORATION	9636	PARK CITY	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.