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
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2024-02-27 | 423-858-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BLOUNTVL | TN |
| 2024-02-27 | 423-858-1XXX | 1000–1999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BLOUNTVL | TN |
| 2024-02-27 | 423-858-8XXX | 8000–8999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BLOUNTVL | TN |
| 2023-08-29 | 423-841-8XXX | 8000–8999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | MOUNTAINCY | TN |
| 2023-04-06 | 423-841-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | MOUNTAINCY | TN |
| 2022-09-07 | 423-460-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | MOUNTAINCY | TN |
| 2022-07-27 | 423-446-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | FALLBRANCH | TN |
| 2022-07-27 | 423-897-5XXX | 5000–5999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | FALLBRANCH | TN |
| 2022-01-09 | 423-446-4XXX | 4000–4999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | FALLBRANCH | TN |
| 2022-01-09 | 423-446-6XXX | 6000–6999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | FALLBRANCH | TN |
| 2022-01-09 | 423-672-8XXX | 8000–8999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2022-01-09 | 423-672-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2017-06-21 | 423-340-7XXX | 7000–7999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BRISTOL | TN |
| 2017-06-21 | 423-340-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BRISTOL | TN |
| 2015-11-30 | 423-270-3XXX | 3000–3999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | ERWIN | TN |
| 2012-05-29 | 423-518-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | ELIZABTHTN | TN |
| 2012-03-16 | 423-530-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | KINGSPORT | TN |
| 2011-06-09 | 423-588-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | GREENEVL | TN |
| 2011-05-25 | 423-948-6XXX | 6000–6999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | LIMESTONE | TN |
| 2011-05-06 | 423-631-6XXX | 6000–6999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2011-05-06 | 423-631-7XXX | 7000–7999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2011-05-06 | 423-631-8XXX | 8000–8999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2011-05-06 | 423-631-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2011-03-04 | 423-398-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | KINGSPORT | TN |
| 2011-02-04 | 423-833-9XXX | 9000–9999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2011-01-18 | 423-579-7XXX | 7000–7999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | KINGSPORT | TN |
| 2010-03-18 | 423-328-6XXX | 6000–6999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2009-10-13 | 423-677-4XXX | 4000–4999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | FALLBRANCH | TN |
| 2009-09-22 | 423-647-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BUTLER | TN |
| 2009-05-11 | 423-930-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2009-04-01 | 423-646-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | BRISTOL | TN |
| 2009-03-16 | 423-328-4XXX | 4000–4999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2009-03-16 | 423-676-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2007-11-14 | 423-433-8XXX | 8000–8999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2007-04-02 | 423-957-3XXX | 3000–3999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | HAMPTON | TN |
| 2007-03-30 | 423-297-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | ELIZABTHTN | TN |
| 2007-03-30 | 423-948-3XXX | 3000–3999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | LIMESTONE | TN |
| 2007-03-23 | 423-291-3XXX | 3000–3999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | MOUNTAINCY | TN |
| 2007-03-12 | 423-343-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | KINGSPORT | TN |
| 2007-03-12 | 423-557-1XXX | 1000–1999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2006-12-22 | 423-342-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | ELIZABTHTN | TN |
| 2006-12-22 | 423-946-6XXX | 6000–6999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2006-10-31 | 423-948-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | LIMESTONE | TN |
| 2006-08-10 | 423-946-4XXX | 4000–4999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2006-05-24 | 423-213-1XXX | 1000–1999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | ELIZABTHTN | TN |
| 2006-05-24 | 423-972-6XXX | 6000–6999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | GREENEVL | TN |
| 2006-03-28 | 423-957-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | HAMPTON | TN |
| 2006-02-02 | 423-557-0XXX | 0000–0999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2006-01-04 | 423-946-1XXX | 1000–1999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | JOHNSON CY | TN |
| 2005-12-19 | 423-291-2XXX | 2000–2999 | Assigned | SUNCOM DBA T-MOBILE USA | 8645 | MOUNTAINCY | 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.