NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 731-599

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 731-599 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 731 blocks

Most active assignees, all time — NPA 731
LEVEL 3 COMMUNICATIONS, LLC - TN 3
CHARTER IP ENABLED SERVICES, LLC 2
BANDWIDTH.COM CLEC, LLC - TN 2
POWERTEL MEMPHIS LICENSES, INC. 1
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 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
Clear Download CSV ↓
Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2013-06-26 731-599-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - TN 4806 UNION CITY TN
2012-07-19 731-599-1XXX 1000–1999Assigned CHARTER IP ENABLED SERVICES, LLC 792K UNION CITY TN
2014-06-13 731-599-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - TN 124F UNION CITY TN
2010-04-15 731-599-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 UNION CITY TN
— 731-599-4XXX 4000–4999Reserved LEVEL 3 COMMUNICATIONS, LLC - TN 4806 UNION CITY TN
2011-08-17 731-599-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C UNION CITY TN
2009-03-09 731-599-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - TN 4806 UNION CITY TN
2015-05-22 731-599-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - TN 124F UNION CITY TN
2006-03-23 731-599-8XXX 8000–8999Assigned POWERTEL MEMPHIS LICENSES, INC. 7474 UNION CITY TN
2005-11-09 731-599-9XXX 9000–9999Assigned CHARTER IP ENABLED SERVICES, LLC 792K UNION CITY TN

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.