NumberResearch Membership · Data 09/20/2026

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 319
QWEST CORPORATION 99
UNITED STATES CELLULAR - IA 39
T-MOBILE USA, INC. 39
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 39
WINDSTREAM IOWA COMMUNICATIONS, INC. 37
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
2011-04-28 319-486 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
2011-04-15 319-777 0–9 XXXall 10 · 5 holders which blocks → AUREON COMMUNICATIONS, LLC 444G CEDAR RPDS IA
2011-03-25 319-499 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
2011-03-22 319-383 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 IOWA CITY IA
2011-02-21 319-488 4XXX6XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 KEYSTONE IA
2010-11-24 319-774 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 CEDAR RPDS IA
2010-09-02 319-529 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 WATERLOO IA
2010-05-06 319-423 0–9 XXXall 10 · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IA 8344 CEDAR RPDS IA
2010-03-23 319-312 0XXX1XXX · 2 holders which blocks → MCC TELEPHONY LLC 593K DYSART IA
2010-03-19 319-203 1XXX3XXX · 2 holders which blocks → MCC TELEPHONY LLC 593K SWISHER IA
2010-03-19 319-285 1XXX5XXX · 2 holders which blocks → MCC TELEPHONY LLC 593K SHARON CTR IA
2010-03-19 319-333 0–9 XXXall 10 · 6 holders which blocks → MCC TELEPHONY LLC 593K IOWA CITY IA
2010-03-19 319-779 1XXX9XXX · 2 holders which blocks → MCC TELEPHONY LLC 593K KALONA IA
2010-03-19 319-844 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → MCC TELEPHONY LLC 593K MONTICELLO IA
2010-03-11 319-820 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 MONTICELLO IA
2010-03-10 319-826 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → MCC TELEPHONY LLC 593K CEDAR RPDS IA
2010-03-09 319-408 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → MCC TELEPHONY LLC 593K LISBON IA
2010-03-08 319-459 0XXX1XXX2XXX · 3 holders which blocks → MCC TELEPHONY LLC 593K NO LIBERTY IA
2009-10-26 319-250 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - IA 221F FT MADISON IA
2009-03-24 319-883 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 WATERLOO IA
2008-12-17 319-425 not yet reported which blocks → MARTELLE COOP TEL ASC DBA MARTELLE COMM COOP IA 351F ANAMOSA IA
2008-12-17 319-720 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → WINDSTREAM IT-COMM, LLC - IA 938D CEDAR RPDS IA
2008-12-15 319-804 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - IA 221F CEDAR RPDS IA
2008-09-30 319-693 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CEDAR RPDS IA
2008-09-08 319-855 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 IOWA CITY IA
2008-07-24 319-432 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - IA 221F CEDAR RPDS IA
2008-05-28 319-775 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - IA 985E CEDAR RPDS IA
2008-05-01 319-999 not yet reported which blocks → ATKINS TELEPHONE COMPANY, INC. - IA 624E CEDAR RPDS IA
2007-12-18 319-538 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - IA 221F CEDAR RPDS IA
2007-06-07 319-429 0–9 XXXall 10 · 5 holders which blocks → UNITED STATES CELLULAR - IA 6266 WATERLOO IA
2007-02-14 319-853 1XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 NO LIBERTY IA
2007-01-30 319-534 9XXX which blocks → MCC TELEPHONY OF IOWA, LLC - IA 751F DANVILLE IA
2006-11-29 319-262 2XXX6XXX · 2 holders which blocks → MCC TELEPHONY LLC 593K KALONA IA
2006-11-29 319-674 4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCC TELEPHONY LLC 593K WELLMAN IA
2006-11-15 319-745 5XXX8XXX · 2 holders which blocks → MCC TELEPHONY LLC 593K W LIBERTY IA
2006-11-15 319-877 7XXX8XXX9XXX · 3 holders which blocks → MCC TELEPHONY LLC 593K WESTBRANCH IA
2006-11-14 319-225 2XXX5XXX7XXX8XXX · 4 holders which blocks → MCC TELEPHONY LLC 593K AMANA IA
2006-11-14 319-244 2XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → MCC TELEPHONY LLC 593K ELY IA
2006-11-14 319-282 2XXX4XXX8XXX9XXX · 4 holders which blocks → MCC TELEPHONY LLC 593K NO ENGLISH IA
2006-11-14 319-322 2XXX3XXX8XXX9XXX · 4 holders which blocks → MCC TELEPHONY LLC 593K NORWAY IA
2006-11-14 319-328 2XXX8XXX9XXX · 3 holders which blocks → MCC TELEPHONY LLC 593K NEWHALL IA
2006-11-14 319-336 3XXX6XXX8XXX9XXX · 4 holders which blocks → MCC TELEPHONY LLC 593K HILLS IA
2006-11-14 319-357 0XXX3XXX8XXX · 3 holders which blocks → MCC TELEPHONY LLC 593K FAIRFAX IA
2006-11-14 319-421 1XXX2XXX4XXX8XXX9XXX · 5 holders which blocks → MCC TELEPHONY LLC 593K SHELL ROCK IA
2006-11-14 319-495 1XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → MCC TELEPHONY LLC 593K LAPORTE CY IA
2006-11-14 319-578 none assigned yet which blocks → MCC TELEPHONY LLC 593K SWISHER IA
2006-07-28 319-884 3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → WINDSTREAM IOWA COMMUNICATIONS, INC. - SYSTEMS 1170 APLINGTON IA
2006-07-24 319-535 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - IA 985E MT VERNON IA
2006-06-12 319-263 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9631 CEDAR RPDS IA
2006-05-15 319-445 4XXX5XXX6XXX7XXX · 3 holders which blocks → MCC TELEPHONY LLC 593K REINBECK IA

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.