NumberResearchThousands-blocks in 858-842
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 858-842 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 858 blocks
Most active assignees, all time — NPA 858
New assignments by month
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2015-03-06 | 858-842-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | POWAY | CA |
| — | 858-842-1XXX | 1000–1999 | Reserved | COMCAST PHONE OF CALIFORNIA, LLC | 394L | POWAY | CA |
| 2005-05-24 | 858-842-2XXX | 2000–2999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | POWAY | CA |
| 2005-01-25 | 858-842-3XXX | 3000–3999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | POWAY | CA |
| 2006-06-05 | 858-842-4XXX | 4000–4999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | POWAY | CA |
| 2011-09-09 | 858-842-5XXX | 5000–5999 | Assigned | ONVOY, LLC - CA | 649C | POWAY | CA |
| 2013-09-19 | 858-842-6XXX | 6000–6999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | POWAY | CA |
| 2007-03-29 | 858-842-7XXX | 7000–7999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | POWAY | CA |
| 2011-06-30 | 858-842-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | POWAY | CA |
| 2016-06-10 | 858-842-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | POWAY | 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.