NumberResearchThousands-blocks in 323-405
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 323-405 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 323 blocks
Most active assignees, all time — NPA 323
New assignments by month
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 323-405-0XXX | 0000–0999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | LSAN DA 04 | CA |
| 2014-05-19 | 323-405-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LSAN DA 04 | CA |
| 2006-05-24 | 323-405-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | LSAN DA 04 | CA |
| 2007-11-21 | 323-405-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | LSAN DA 04 | CA |
| 2014-05-19 | 323-405-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LSAN DA 04 | CA |
| 2007-01-11 | 323-405-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | LSAN DA 04 | CA |
| 2015-04-22 | 323-405-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | LSAN DA 04 | CA |
| 2010-01-28 | 323-405-7XXX | 7000–7999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LSAN DA 04 | CA |
| 2010-02-08 | 323-405-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | LSAN DA 04 | CA |
| 2018-11-30 | 323-405-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | LSAN DA 04 | 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.