NumberResearchThousands-blocks in 323-406
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 323-406 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
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2008-01-16 | 323-406-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | LSAN DA 05 | CA |
| 2015-06-30 | 323-406-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LSAN DA 05 | CA |
| 2006-06-09 | 323-406-2XXX | 2000–2999 | Assigned | AT&T ENTERPRISES, LLC | 516C | LSAN DA 05 | CA |
| 2006-06-12 | 323-406-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | LSAN DA 05 | CA |
| 2016-09-16 | 323-406-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | LSAN DA 05 | CA |
| — | 323-406-5XXX | 5000–5999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | LSAN DA 05 | CA |
| 2016-07-06 | 323-406-6XXX | 6000–6999 | Assigned | PEERLESS NETWORK OF CALIFORNIA, LLC - CA | 373F | LSAN DA 05 | CA |
| 2008-05-20 | 323-406-7XXX | 7000–7999 | Assigned | ONVOY, LLC - CA | 649C | LSAN DA 05 | CA |
| 2012-09-04 | 323-406-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LSAN DA 05 | CA |
| 2012-09-04 | 323-406-9XXX | 9000–9999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | LSAN DA 05 | 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.