NumberResearchThousands-blocks in 424-203
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 424-203 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 424 blocks
Most active assignees, all time — NPA 424
New assignments by month
Sep 2026
Aug 2026
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Jun 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2007-11-07 | 424-203-0XXX | 0000–0999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | LOMITA | CA |
| 2007-07-16 | 424-203-1XXX | 1000–1999 | Assigned | PAETEC ITEL, LLC | 829J | LOMITA | CA |
| 2006-12-01 | 424-203-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | LOMITA | CA |
| 2007-02-01 | 424-203-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | LOMITA | CA |
| 2008-03-14 | 424-203-4XXX | 4000–4999 | Assigned | ONVOY, LLC - CA | 649C | LOMITA | CA |
| 2007-02-06 | 424-203-5XXX | 5000–5999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LOMITA | CA |
| 2012-12-03 | 424-203-6XXX | 6000–6999 | Assigned | ONVOY, LLC - CA | 649C | LOMITA | CA |
| 2007-02-13 | 424-203-7XXX | 7000–7999 | Assigned | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | LOMITA | CA |
| 2007-02-13 | 424-203-8XXX | 8000–8999 | Assigned | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | LOMITA | CA |
| 2007-02-22 | 424-203-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | LOMITA | 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.