NumberResearchThousands-blocks in 423-393
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 423-393 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 423 blocks
Most active assignees, all time — NPA 423
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 423-393-0XXX | 0000–0999 | Available | BULLS GAP | TN | ||
| 2005-04-28 | 423-393-1XXX | 1000–1999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | BULLS GAP | TN |
| 2008-05-08 | 423-393-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BULLS GAP | TN |
| 2010-02-02 | 423-393-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - TN | 124F | BULLS GAP | TN |
| 2008-10-22 | 423-393-4XXX | 4000–4999 | Assigned | COMCAST IP PHONE, LLC | 318J | BULLS GAP | TN |
| 2011-10-20 | 423-393-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | BULLS GAP | TN |
| 2021-11-09 | 423-393-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - TN | 124F | BULLS GAP | TN |
| 2012-05-02 | 423-393-7XXX | 7000–7999 | Assigned | BANDWIDTH.COM CLEC, LLC - TN | 124F | BULLS GAP | TN |
| 2015-05-19 | 423-393-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - TN | 124F | BULLS GAP | TN |
| 2016-05-23 | 423-393-9XXX | 9000–9999 | Assigned | ONVOY, LLC - TN | 525E | BULLS GAP | TN |
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.