NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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 501
SOUTHWESTERN BELL 165
NEW CINGULAR WIRELESS PCS, LLC - IL 86
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 54
LEVEL 3 COMMUNICATIONS, LLC - AR 48
T-MOBILE USA, INC. 42
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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2011-10-20 501-313 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J LITTLEROCK AR
2011-10-14 501-264 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-10-10 501-267 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 MALVERN AR
2011-10-06 501-308 1XXX2XXX3XXX4XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-09-22 501-248 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-08-25 501-216 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-08-02 501-444 0XXX1XXX2XXX4XXX5XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-07-06 501-234 0–9 XXXall 10 · 3 holders which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 LITTLEROCK AR
2011-06-22 501-272 0XXX1XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-06-02 501-243 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2011-05-06 501-237 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 LONOKE AR
2011-03-24 501-400 0–9 XXXall 10 · 5 holders which blocks → PAETEC ITEL, LLC 829J LITTLEROCK AR
2010-02-16 501-422 0–9 XXXall 10 · 7 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 CABOT AR
2010-01-18 501-302 0–9 XXXall 10 · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - AR 802C HEBER SPG AR
2010-01-08 501-294 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MORGANTON AR
2009-11-18 501-306 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 QUITMAN AR
2009-04-16 501-850 0–9 XXXall 10 · 2 holders which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 LITTLEROCK AR
2008-12-22 501-286 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CABOT AR
2008-10-31 501-295 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - AR 348F LITTLEROCK AR
2008-07-18 501-314 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GREENBRIER AR
2008-07-15 501-291 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - AR 196F LITTLEROCK AR
2008-03-27 501-287 0–9 XXXall 10 · 5 holders which blocks → WINDSTREAM ARKANSAS, INC. 1691 GREENBRIER AR
2008-01-28 501-410 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2008-01-03 501-476 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - AR 348F LITTLEROCK AR
2007-09-14 501-414 0–9 XXXall 10 · 2 holders which blocks → COMCAST IP PHONE, LLC 318J LITTLEROCK AR
2007-06-26 501-651 0–9 XXXall 10 · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - AR 802C HOTSPRINGS AR
2007-03-08 501-251 0–9 XXXall 10 · 5 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
2006-08-07 501-699 0XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 SCOTLAND AR
2006-08-07 501-757 0XXX1XXX2XXX3XXX5XXX7XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 CLINTON AR
2006-06-15 501-322 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 KENSETT AR
2006-05-23 501-456 1XXX4XXX7XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 JUDSONIA AR
2006-01-19 501-864 0–9 XXXall 10 · 4 holders which blocks → AT&T ENTERPRISES, LLC 516C SYVNHLSHWD AR
2005-12-30 501-434 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 MCRAE AR
2005-12-30 501-858 0XXX1XXX2XXX3XXX4XXX5XXX6XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 BEEBE AR
2005-12-14 501-388 7XXX8XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 SEARCY AR
2005-10-27 501-353 0–9 XXXall 10 · 2 holders which blocks → COMCAST IP PHONE, LLC 318J LITTLEROCK AR
2005-10-17 501-613 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2005-08-16 501-650 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2005-07-14 501-289 3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 MORRILTON AR
2005-07-05 501-530 2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 BALD KNOB AR
2005-06-20 501-802 8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 JONESMILLS AR
2005-04-07 501-747 0–9 XXXall 10 · 3 holders which blocks → AT&T ENTERPRISES, LLC 516C LITTLEROCK AR
2005-03-17 501-366 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 LITTLEROCK AR
2004-09-28 501-246 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J LITTLEROCK AR
2004-06-01 501-253 7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CLINTON AR
2004-04-29 501-232 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 BEEBE AR
2004-01-27 501-442 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
2003-08-05 501-288 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BEEBE AR
2003-07-23 501-631 0XXX1XXX3XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-632 7XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.