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
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2024-09-10 | 423-671-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2023-08-10 | 423-275-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2023-05-19 | 423-809-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | PIKEVILLE | TN |
| 2023-05-19 | 423-852-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | DUNLAP | TN |
| 2023-02-01 | 423-749-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | COLLEGEDL | TN |
| 2022-12-20 | 423-236-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | APISON | TN |
| 2022-08-30 | 423-671-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2021-09-09 | 423-577-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | ONEIDA | TN |
| 2021-09-09 | 423-632-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | WARTBURG | TN |
| 2021-07-20 | 423-850-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | JONESBORO | TN |
| 2021-05-03 | 423-770-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHURCHHILL | TN |
| 2020-09-24 | 423-264-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | VONORE | TN |
| 2020-08-04 | 423-269-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2018-08-02 | 423-500-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | ROGERSVL | TN |
| 2018-07-31 | 423-651-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | JASPER | TN |
| 2018-04-16 | 423-910-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | OOLTEWAH | TN |
| 2018-03-13 | 423-497-1XXX | 1000–1999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2017-09-27 | 423-758-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BRISTOL | TN |
| 2017-08-29 | 423-417-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2017-06-20 | 423-758-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BRISTOL | TN |
| 2017-04-24 | 423-498-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2017-02-27 | 423-498-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2016-12-29 | 423-767-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | JOHNSON CY | TN |
| 2016-10-04 | 423-652-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BRISTOL | TN |
| 2016-06-01 | 423-682-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2015-07-07 | 423-661-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2014-07-29 | 423-441-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CUMBERLDGP | TN |
| 2014-07-25 | 423-551-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2014-06-24 | 423-259-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | NEWTAZWELL | TN |
| 2014-04-08 | 423-345-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | SURGOINSVL | TN |
| 2014-03-28 | 423-419-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CUMBERLDGP | TN |
| 2014-03-25 | 423-281-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BUTLER | TN |
| 2014-03-25 | 423-422-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | MOSHEIM | TN |
| 2014-03-25 | 423-481-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | ROAN MT | TN |
| 2014-03-25 | 423-512-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | STONEY CRK | TN |
| 2014-03-25 | 423-516-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | SULIVNGDNS | TN |
| 2014-03-25 | 423-528-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BAILEYTON | TN |
| 2014-03-21 | 423-425-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2014-03-03 | 423-635-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2014-03-03 | 423-900-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | JOHNSON CY | TN |
| 2014-02-13 | 423-458-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CLEVELAND | TN |
| 2013-12-27 | 423-207-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | MIDWAY | TN |
| 2013-09-12 | 423-805-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2013-07-11 | 423-742-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BRISTOL | TN |
| 2013-06-26 | 423-353-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | MORRISTOWN | TN |
| 2013-02-07 | 423-391-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BLUFF CITY | TN |
| 2012-12-27 | 423-602-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2012-11-02 | 423-800-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | CHATTNOOGA | TN |
| 2012-10-19 | 423-793-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BRISTOL | TN |
| 2012-10-17 | 423-212-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - TN | 4806 | BLOUNTVL | 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.