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
— 563-445 not yet reported which blocks → QWEST CORPORATION 9631 DAVENPORT IA
— 563-449 2XXX4XXX5XXX6XXX · 2 holders which blocks → QWEST CORPORATION 9631 DAVENPORT IA
— 563-451 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → AT&T - LOCAL 7421 DUBUQUE IA
— 563-452 not yet reported which blocks → CLARENCE TEL. CO. INC. 1130 CLARENCE IA
— 563-459 7XXX8XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9631 DAVENPORT IA
— 563-468 0XXX1XXX3XXX7XXX8XXX9XXX which blocks → QWEST CORPORATION 9631 DAVENPORT IA
— 563-485 not yet reported which blocks → ONSLOW COOP. TEL. ASSN. 1265 ONSLOW IA
— 563-486 0XXX2XXX · 2 holders which blocks → MCC TELEPHONY OF IOWA, LLC - IA 751F OXFORD JCT IA
— 563-487 not yet reported which blocks → CENTER JUNCTION TEL. CO. 1121 CENTER JCT IA
— 563-488 not yet reported which blocks → WYOMING MUTUAL TEL. CO. 1343 WYOMING IA
— 563-492 not yet reported which blocks → SPRING GROVE COMMUNICATIONS 1485 SOSPGGROVE IA
— 563-495 not yet reported which blocks → T-MOBILE USA, INC. 6529 DUBUQUE IA
— 563-496 not yet reported which blocks → MABEL TEL. COOP. CO. - MN 1421 HESPER IA
— 563-497 not yet reported which blocks → ACE TEL. ASSN. - MN 1345 DORCHESTER IA
— 563-499 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → AT&T - LOCAL 7421 DAVENPORT IA
— 563-503 2XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → METROPCS, INC. 5562 CLINTON IA
— 563-505 none assigned yet which blocks → T-MOBILE USA, INC. 6529 DAVENPORT IA
— 563-506 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 MUSCATINE IA
— 563-508 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DAVENPORT IA
— 563-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX IA
— 563-514 0–9 XXXall 10 · 5 holders which blocks → NUSO, LLC 732J DAVENPORT IA
— 563-515 not yet reported which blocks → IA
— 563-516 1XXX7XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 ELKADER IA
— 563-517 1XXX2XXX7XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 DECORAH IA
— 563-518 1XXX5XXX6XXX7XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 WEST UNION IA
— 563-522 0XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → WINDSTREAM IOWA COMMUNICATIONS, INC. - SYSTEMS 1170 LOW MOOR IA
— 563-529 none assigned yet which blocks → T-MOBILE USA, INC. 6529 DAVENPORT IA
— 563-532 not yet reported which blocks → ACE TEL. ASSN. - IA 1346 OSSIAN IA
— 563-534 not yet reported which blocks → ACE TEL. ASSN. - IA 1346 FTATKINSON IA
— 563-535 not yet reported which blocks → ACE TEL. ASSN. - IA 1346 WATERVILLE IA
— 563-536 not yet reported which blocks → NORTHEAST IOWA TEL. CO. 1230 FARMERSBG IA
— 563-538 0XXX1XXX2XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → QWEST CORPORATION 9631 LANSING IA
— 563-539 not yet reported which blocks → NORTHEAST IOWA TEL. CO. 1230 MONONA IA
— 563-543 none assigned yet which blocks → UNITED STATES CELLULAR - IA 6266 DUBUQUE IA
— 563-544 not yet reported which blocks → ACE TEL. ASSN. - IA 1346 NEW ALBIN IA
— 563-546 not yet reported which blocks → ACE TEL. ASSN. - IA 1346 HIGHLANDVL IA
— 563-547 0XXX8XXX which blocks → WINDSTREAM IOWA COMMUNICATIONS, INC. - NORTH 1167 CRESCO IA
— 563-552 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → QWEST CORPORATION 9631 DUBUQUE IA
— 563-554 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 MUSCATINE IA
— 563-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST IA
— 563-556 not yet reported which blocks → QWEST CORPORATION 9631 DUBUQUE IA
— 563-557 not yet reported which blocks → QWEST CORPORATION 9631 DUBUQUE IA
— 563-559 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 CLINTON IA
— 563-562 0XXX1XXX2XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → QWEST CORPORATION 9631 CALMAR IA
— 563-563 not yet reported which blocks → IA
— 563-564 2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 DUBUQUE IA
— 563-565 7XXX which blocks → CENTURYTEL OF CHESTER, INC. DBA CENTURYLINK 1126 CHESTER IA
— 563-566 3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → WINDSTREAM IOWA COMMUNICATIONS, INC. 1178 LIME SPG IA
— 563-567 not yet reported which blocks → ACE TEL. ASSN. - IA 1346 CASTALIA IA
— 563-568 1XXX7XXX8XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9631 WAUKON 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.