NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 559-537

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 559-537 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 559 blocks

Most active assignees, all time — NPA 559
TELEPORT COMMUNICATIONS AMERICA, LLC - CA 5
BANDWIDTH.COM CLEC, LLC - CA 3
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 1
T-MOBILE USA, 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
2010-03-08 559-537-0XXX 0000–0999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 HANFORD CA
2010-03-08 559-537-1XXX 1000–1999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 HANFORD CA
2010-03-08 559-537-2XXX 2000–2999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 HANFORD CA
2010-03-08 559-537-3XXX 3000–3999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 HANFORD CA
2010-03-08 559-537-4XXX 4000–4999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 HANFORD CA
2011-05-26 559-537-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E HANFORD CA
2014-03-18 559-537-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E HANFORD CA
2011-05-06 559-537-7XXX 7000–7999Assigned U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J HANFORD CA
2014-03-18 559-537-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E HANFORD CA
2012-03-22 559-537-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 HANFORD CA

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.