NumberResearchThousands-blocks in 559-423
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
The ten 1,000-number thousand-blocks inside prefix 559-423 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
New assignments by month
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2010-10-01 | 559-423-0XXX | 0000–0999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LEMOORE | CA |
| — | 559-423-1XXX | 1000–1999 | Reserved | IP HORIZON LLC | 515J | LEMOORE | CA |
| — | 559-423-2XXX | 2000–2999 | Reserved | IP HORIZON LLC | 515J | LEMOORE | CA |
| 2014-07-14 | 559-423-3XXX | 3000–3999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | LEMOORE | CA |
| 2020-06-09 | 559-423-4XXX | 4000–4999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | LEMOORE | CA |
| 2006-07-19 | 559-423-5XXX | 5000–5999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | LEMOORE | CA |
| 2004-10-19 | 559-423-6XXX | 6000–6999 | Assigned | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | LEMOORE | CA |
| 2013-02-18 | 559-423-7XXX | 7000–7999 | Assigned | ONVOY, LLC - CA | 649C | LEMOORE | CA |
| 2008-08-04 | 559-423-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | LEMOORE | CA |
| 2013-11-26 | 559-423-9XXX | 9000–9999 | Assigned | PEERLESS NETWORK OF CALIFORNIA, LLC - CA | 373F | LEMOORE | 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.