NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 641-231

This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The ten 1,000-number thousand-blocks inside prefix 641-231 and who was initially assigned each. Under pooling these blocks often belong to different carriers — the single prefix-level “assignee” is usually just the pool / code holder, not who holds the numbers. ← all 641 blocks

Most active assignees, all time — NPA 641
UNITED STATES CELLULAR - IA 4
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 3
T-MOBILE USA, INC. 2
MCC TELEPHONY OF IOWA, LLC - IA 1
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 thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2015-04-13 641-231-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 CLEAR LAKE IA
2004-11-29 641-231-1XXX 1000–1999Assigned UNITED STATES CELLULAR - IA 6266 CLEAR LAKE IA
2012-09-24 641-231-2XXX 2000–2999Assigned UNITED STATES CELLULAR - IA 6266 CLEAR LAKE IA
2018-03-01 641-231-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 CLEAR LAKE IA
2015-09-15 641-231-4XXX 4000–4999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 CLEAR LAKE IA
2016-04-27 641-231-5XXX 5000–5999Assigned UNITED STATES CELLULAR - IA 6266 CLEAR LAKE IA
2016-10-17 641-231-6XXX 6000–6999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA 6570 CLEAR LAKE IA
2018-03-01 641-231-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 CLEAR LAKE IA
2010-03-04 641-231-8XXX 8000–8999Assigned MCC TELEPHONY OF IOWA, LLC - IA 751F CLEAR LAKE IA
2020-12-16 641-231-9XXX 9000–9999Assigned UNITED STATES CELLULAR - IA 6266 CLEAR LAKE IA

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.