NumberResearchRecent thousands-block assignments
0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026
Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.
Most active assignees, all time — NPA 423
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2026-01-27 | 423-969-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CLEVELAND | TN |
| 2019-02-04 | 423-830-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | KINGSPORT | TN |
| 2018-03-20 | 423-806-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | MIDWAY | TN |
| 2017-08-24 | 423-417-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHATTNOOGA | TN |
| 2017-05-23 | 423-856-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | ATHENS | TN |
| 2016-12-20 | 423-528-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | BAILEYTON | TN |
| 2016-11-10 | 423-445-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | SURGOINSVL | TN |
| 2016-11-10 | 423-546-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | BULLS GAP | TN |
| 2016-09-07 | 423-594-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | DAYTON | TN |
| 2016-08-23 | 423-845-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | BRISTOL | TN |
| 2016-03-25 | 423-651-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | JASPER | TN |
| 2016-02-10 | 423-460-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | MOUNTAINCY | TN |
| 2016-02-10 | 423-788-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | JONESBORO | TN |
| 2015-02-09 | 423-491-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | JOHNSON CY | TN |
| 2015-02-05 | 423-708-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHATTNOOGA | TN |
| 2014-08-25 | 423-592-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | LAFOLLETTE | TN |
| 2013-04-12 | 423-516-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | SULIVNGDNS | TN |
| 2013-03-12 | 423-800-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHATTNOOGA | TN |
| 2011-11-29 | 423-301-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | SO PITTSBG | TN |
| 2011-11-22 | 423-735-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | ERWIN | TN |
| 2011-07-05 | 423-241-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | COPPERBSIN | TN |
| 2011-07-05 | 423-436-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | MADISONVL | TN |
| 2011-07-05 | 423-781-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | ETOWAH | TN |
| 2011-01-18 | 423-414-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHATTNOOGA | TN |
| 2010-11-19 | 423-381-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | ATHENS | TN |
| 2010-05-25 | 423-707-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | ELIZABTHTN | TN |
| 2010-02-10 | 423-406-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | MIDWAY SUL | TN |
| 2009-12-14 | 423-347-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | ROGERSVL | TN |
| 2009-02-10 | 423-391-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | BLUFF CITY | TN |
| 2009-02-10 | 423-948-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | LIMESTONE | TN |
| 2008-09-30 | 423-662-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | BLOUNTVL | TN |
| 2008-08-27 | 423-591-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHATTNOOGA | TN |
| 2007-08-06 | 423-256-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHURCHHILL | TN |
| 2007-02-26 | 423-217-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | BRISTOL | TN |
| 2007-02-26 | 423-278-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | GREENEVL | TN |
| 2007-02-26 | 423-765-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | KINGSPORT | TN |
| 2007-02-09 | 423-790-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CLEVELAND | TN |
| 2007-02-05 | 423-465-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | NEWPORT | TN |
| 2005-01-05 | 423-200-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | MORRISTOWN | TN |
| 2003-12-23 | 423-202-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | JOHNSON CY | TN |
| 2003-07-10 | 423-535-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN | 7278 | CHATTNOOGA | TN |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.