NumberResearchThousands-blocks in 405-256
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 405-256 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 405 blocks
Most active assignees, all time — NPA 405
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 405-256-0XXX | 0000–0999 | Reserved | COMCAST IP PHONE, LLC | 318J | MUSTANG | OK |
| 2015-09-23 | 405-256-1XXX | 1000–1999 | Assigned | PEERLESS NETWORK OF OKLAHOMA, LLC - OK | 384H | MUSTANG | OK |
| 2011-03-04 | 405-256-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - OK | 119F | MUSTANG | OK |
| 2012-07-19 | 405-256-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - OK | 119F | MUSTANG | OK |
| 2014-05-15 | 405-256-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - OK | 119F | MUSTANG | OK |
| 2008-08-12 | 405-256-5XXX | 5000–5999 | Assigned | COMCAST IP PHONE, LLC | 318J | MUSTANG | OK |
| 2006-03-21 | 405-256-6XXX | 6000–6999 | Assigned | COMCAST IP PHONE, LLC | 318J | MUSTANG | OK |
| 2006-10-30 | 405-256-7XXX | 7000–7999 | Assigned | AT&T ENTERPRISES, LLC | 516C | MUSTANG | OK |
| 2015-04-29 | 405-256-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - OK | 119F | MUSTANG | OK |
| 2017-06-07 | 405-256-9XXX | 9000–9999 | Assigned | TELNYX LLC | 073H | MUSTANG | OK |
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.