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 972

SOUTHWESTERN BELL 307

FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 183

NEW CINGULAR WIRELESS PCS, LLC - IL 58

MCIMETRO ACCESS TRANSMISSION SERVICES LLC 55

ONVOY, LLC - TX 24

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
—	972-602	5XXX which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-603	5XXX6XXX8XXX which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-604	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	PLANO	TX
—	972-605	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	PLANO	TX
—	972-606	not yet reported which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-607	0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-608	3XXX7XXX · 2 holders which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	PLANO	TX
—	972-609	not yet reported which blocks →	SPOK, INC.	6630	GRANDPRARI	TX
—	972-610	not yet reported which blocks →	SOUTHWESTERN BELL	9533	XXXXXXXXXX	TX
—	972-611	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	TX
—	972-612	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	PLANO	TX
—	972-613	3XXX which blocks →	SOUTHWESTERN BELL	9533	DALLAS	TX
—	972-614	6XXX which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-615	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	DLFTWTARPT	TX
—	972-616	3XXX4XXX which blocks →	LEVEL 3 OF TELECOM OF TEXAS, LLC - TX	7516	DALLAS	TX
—	972-617	not yet reported which blocks →	SOUTHWESTERN BELL	9533	RED OAK	TX
—	972-618	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	PLANO	TX
—	972-619	3XXX5XXX6XXX7XXX9XXX · 2 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - TX	7148	DALLAS	TX
—	972-620	not yet reported which blocks →	SOUTHWESTERN BELL	9533	DALLAS	TX
—	972-621	1XXX9XXX which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-622	not yet reported which blocks →	SPOK, INC.	6630	GRANDPRARI	TX
—	972-623	7XXX8XXX · 2 holders which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-624	6XXX7XXX9XXX · 2 holders which blocks →	SOUTHWESTERN BELL	9533	FRISCO	TX
—	972-625	not yet reported which blocks →	SOUTHWESTERN BELL	9533	FRISCO	TX
—	972-627	1XXX2XXX4XXX7XXX8XXX9XXX · 5 holders which blocks →	VALOR TELECOMM TX, LD-TX #2 DBA WINDSTREAM COMM SW	1181	AVALON	TX
—	972-628	0XXX which blocks →	SOUTHWESTERN BELL	9533	DALLAS	TX
—	972-629	6XXX9XXX · 2 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - TX	7148	DALLAS	TX
—	972-630	0XXX3XXX4XXX6XXX8XXX9XXX · 2 holders which blocks →	SOUTHWESTERN BELL	9533	DALLAS	TX
—	972-631	not yet reported which blocks →	AMERICAN MESSAGING SERVICES, LLC	9748	MCKINNEY	TX
—	972-632	0–9 XXXall 10 · 2 holders which blocks →	ONVOY, LLC - TX	903C	MCKINNEY	TX
—	972-633	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	PLANO	TX
—	972-635	0XXX3XXX4XXX5XXX8XXX · 3 holders which blocks →	SOUTHWESTERN BELL	9533	ROYSE CITY	TX
—	972-636	1XXX4XXX5XXX6XXX8XXX · 3 holders which blocks →	SOUTHWESTERN BELL	9533	ROYSE CITY	TX
—	972-637	1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 OF TELECOM OF TEXAS, LLC - TX	7516	CEDAR HILL	TX
—	972-641	not yet reported which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-642	not yet reported which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-643	8XXX which blocks →	SOUTHWESTERN BELL	9533	DALLAS	TX
—	972-644	not yet reported which blocks →	SOUTHWESTERN BELL	9533	DALLAS	TX
—	972-646	0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	2154	BARDWELL	TX
—	972-647	not yet reported which blocks →	SOUTHWESTERN BELL	9533	GRANDPRARI	TX
—	972-648	not yet reported which blocks →	AMERICAN MESSAGING SERVICES, LLC	9748	GRANDPRARI	TX
—	972-649	1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 3 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	ALLEN	TX
—	972-650	not yet reported which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-651	not yet reported which blocks →	GRANDE COMMUNICATIONS NETWORKS, INC. - TX	7670	ROCKWALL	TX
—	972-652	0XXX2XXX3XXX8XXX · 3 holders which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-653	0XXX2XXX which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-655	4XXX6XXX8XXX9XXX which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-656	0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	7229	DALLAS	TX
—	972-657	0XXX which blocks →	FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS	4344	IRVING	TX
—	972-658	not yet reported which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	MCKINNEY	TX

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.