NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 504-521

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 504-521 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 504 blocks

Most active assignees, all time — NPA 504
NEW CINGULAR WIRELESS PCS, LLC - GA 4
BELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL 3
BANDWIDTH.COM CLEC, LLC - LA 2
METROPCS, INC. 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
— 504-521-0XXX 0000–0999Reserved BELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL 9419 NEWORLEANS LA
— 504-521-1XXX 1000–1999Reserved BELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL 9419 NEWORLEANS LA
2020-02-21 504-521-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - GA 6214 NEWORLEANS LA
2020-02-21 504-521-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC - GA 6214 NEWORLEANS LA
2020-02-21 504-521-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - GA 6214 NEWORLEANS LA
2019-12-12 504-521-5XXX 5000–5999Assigned METROPCS, INC. 5562 NEWORLEANS LA
2010-05-25 504-521-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - LA 153F NEWORLEANS LA
2010-10-18 504-521-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - LA 153F NEWORLEANS LA
— 504-521-8XXX 8000–8999Reserved BELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL 9419 NEWORLEANS LA
2020-02-21 504-521-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC - GA 6214 NEWORLEANS LA

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.