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 563
QWEST CORPORATION 54
UNITED STATES CELLULAR - IA 33
WINDSTREAM IOWA COMMUNICATIONS, INC. - NORTH 26
T-MOBILE USA, INC. 25
WINDSTREAM IOWA COMMUNICATIONS, INC. - SYSTEMS 22
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
2021-06-21 563-560 0XXX5XXX · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H LANSING IA
2021-06-03 563-644 0XXX1XXX2XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → TON80 COMMUNICATIONS, LLC 516J DECORAH IA
2021-05-10 563-842 2XXX5XXX6XXX · 3 holders which blocks → FRACTEL, LLC 965H HOLY CROSS IA
2021-04-29 563-844 0–9 XXXall 10 · 4 holders which blocks → TERRA NOVA TELECOM INC. 145J DAVENPORT IA
2021-04-02 563-867 0–9 XXXall 10 · 2 holders which blocks → COMMIO, LLC 939H DAVENPORT IA
2021-04-01 563-306 0–9 XXXall 10 · 3 holders which blocks → IP HORIZON LLC 515J DAVENPORT IA
2021-03-11 563-294 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → AIRUS, INC - IA 423H WEST UNION IA
2021-01-11 563-291 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - IA 221F DUBUQUE IA
2020-10-23 563-895 0–9 XXXall 10 · 5 holders which blocks → TWILIO INTERNATIONAL, INC. 506J DAVENPORT IA
2020-08-05 563-290 2XXX3XXX5XXX9XXX · 3 holders which blocks → HAWKEYE INTERCONNECT COMPANY - IA 429J WAUCOMA IA
2020-07-23 563-296 0–9 XXXall 10 · 4 holders which blocks → CSC WIRELESS, LLC 425J DAVENPORT IA
2020-07-21 563-348 0–9 XXXall 10 · 5 holders which blocks → FRACTEL, LLC 965H DUBUQUE IA
2020-07-21 563-465 0XXX3XXX4XXX6XXX8XXX · 5 holders which blocks → FRACTEL, LLC 965H FARLEY IA
2020-07-21 563-758 1XXX6XXX8XXX · 3 holders which blocks → FRACTEL, LLC 965H WORTHINGTN IA
2020-07-21 563-877 1XXX7XXX8XXX · 3 holders which blocks → FRACTEL, LLC 965H EARLVILLE IA
2019-12-23 563-500 0–9 XXXall 10 · 3 holders which blocks → FRACTEL, LLC 965H DUBUQUE IA
2019-12-23 563-766 1XXX3XXX5XXX6XXX7XXX · 3 holders which blocks → FRACTEL, LLC 965H COLESBURG IA
2019-12-23 563-900 0–9 XXXall 10 · 6 holders which blocks → FRACTEL, LLC 965H DAVENPORT IA
2019-12-19 563-356 0XXX1XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → FRACTEL, LLC 965H CHESTER IA
2019-12-17 563-400 0–9 XXXall 10 · 4 holders which blocks → FRACTEL, LLC 965H CRESCO IA
2019-12-17 563-600 0–9 XXXall 10 · 2 holders which blocks → FRACTEL, LLC 965H LANSING IA
2019-12-06 563-298 3XXX7XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GUTTENBERG IA
2019-11-26 563-283 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → HD CARRIER LLC 321J MUSCATINE IA
2019-11-26 563-287 0–9 XXXall 10 · 3 holders which blocks → AIRUS, INC - IA 423H DECORAH IA
2019-11-21 563-286 0–9 XXXall 10 · 4 holders which blocks → TELNYX LLC 073H DAVENPORT IA
2019-11-20 563-551 0–9 XXXall 10 · 6 holders which blocks → WIDE VOICE, LLC - IA 722G DAVENPORT IA
2019-10-30 563-279 0–9 XXXall 10 · 4 holders which blocks → AIRUS, INC - IA 423H DAVENPORT IA
2019-08-29 563-281 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - IA 221F MUSCATINE IA
2019-08-27 563-276 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - IA 221F WAUKON IA
2019-08-27 563-278 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - IA 221F CLINTON IA
2019-06-18 563-337 2XXX3XXX6XXX7XXX · 3 holders which blocks → HAWKEYE INTERCONNECT COMPANY - IA 429J FAYETTE IA
2018-06-28 563-236 2XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 ANDREW IA
2018-06-28 563-240 2XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 LAMOTTE IA
2018-06-28 563-266 2XXX5XXX6XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 BERNARD IA
2018-06-28 563-268 2XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 BALDWIN IA
2018-06-28 563-269 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 CASCADE IA
2018-06-28 563-270 0XXX2XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 CENTER JCT IA
2018-06-28 563-273 2XXX3XXX6XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 ONSLOW IA
2018-06-28 563-274 2XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - IA 9877 OTTERCREEK IA
2018-06-14 563-227 0–9 XXXall 10 · 6 holders which blocks → MCC TELEPHONY OF IOWA, LLC - IA 751F DUBUQUE IA
2018-06-05 563-526 0–9 XXXall 10 · 6 holders which blocks → VONAGE AMERICA LLC 197D DAVENPORT IA
2018-02-16 563-800 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - IA 221F CALMAR IA
2018-02-12 563-396 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 DAVENPORT IA
2018-02-07 563-292 0–9 XXXall 10 · 5 holders which blocks → AIRUS, INC - IA 423H WEST UNION IA
2018-02-07 563-334 0–9 XXXall 10 · 6 holders which blocks → AIRUS, INC - IA 423H DECORAH IA
2017-09-29 563-666 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - IA 221F WALCOTT IA
2017-08-16 563-261 0–9 XXXall 10 · 6 holders which blocks → IMON COMMUNICATIONS, LLC - IA 695G MUSCATINE IA
2017-08-14 563-200 0–9 XXXall 10 · 5 holders which blocks → ONVOY SPECTRUM, LLC 624H DAVENPORT IA
2016-11-14 563-253 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → WINDSTREAM IOWA COMMUNICATIONS, INC. - SYSTEMS 1170 TIPTON IA
2016-09-23 563-239 0–9 XXXall 10 · 7 holders which blocks → MCC TELEPHONY OF IOWA, LLC - IA 751F DUBUQUE 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.