NumberResearchThousands-blocks in 951-643
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 951-643 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 951 blocks
Most active assignees, all time — NPA 951
New assignments by month
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2004-12-09 | 951-643-0XXX | 0000–0999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | ARLINGTON | CA |
| 2013-03-12 | 951-643-1XXX | 1000–1999 | Assigned | TWC IP ENABLED SERVICES, LLC | 793K | ARLINGTON | CA |
| 2013-04-03 | 951-643-2XXX | 2000–2999 | Assigned | PEERLESS NETWORK OF CALIFORNIA, LLC - CA | 373F | ARLINGTON | CA |
| 2004-12-09 | 951-643-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | ARLINGTON | CA |
| — | 951-643-4XXX | 4000–4999 | Reserved | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | ARLINGTON | CA |
| 2005-01-31 | 951-643-5XXX | 5000–5999 | Assigned | PAETEC ITEL, LLC | 829J | ARLINGTON | CA |
| 2013-02-04 | 951-643-6XXX | 6000–6999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | ARLINGTON | CA |
| 2005-03-31 | 951-643-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | ARLINGTON | CA |
| 2005-03-31 | 951-643-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | ARLINGTON | CA |
| 2009-03-18 | 951-643-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | ARLINGTON | 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.