NumberResearchRecent thousands-block assignments
0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/25/2026
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 346
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2022-06-28 | 346-552-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | ALVIN | TX |
| 2022-01-05 | 346-542-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | HOUSTON | TX |
| 2022-01-05 | 346-542-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | HOUSTON | TX |
| 2021-07-23 | 346-470-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HUMBLE | TX |
| 2020-10-09 | 346-786-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPRING | TX |
| 2020-10-09 | 346-786-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPRING | TX |
| 2019-12-09 | 346-426-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | HOUSTON | TX |
| 2019-09-30 | 346-398-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2019-09-30 | 346-398-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2018-10-18 | 346-372-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | SPRING | TX |
| 2018-07-18 | 346-348-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2018-07-18 | 346-348-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2018-02-07 | 346-815-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | APOLLO | TX |
| 2017-10-19 | 346-279-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | SUGAR LAND | TX |
| 2017-09-29 | 346-272-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2017-09-29 | 346-272-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2017-09-29 | 346-272-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2017-06-01 | 346-310-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2017-06-01 | 346-310-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2017-05-31 | 346-310-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2017-05-18 | 346-907-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HSTNSUBURB | TX |
| 2017-02-03 | 346-787-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | LA PORTE | TX |
| 2016-10-04 | 346-236-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | TOMBALL | TX |
| 2016-07-13 | 346-352-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2016-04-29 | 346-352-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2016-01-29 | 346-232-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2016-01-29 | 346-232-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2015-08-19 | 346-307-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | KATY | TX |
| 2015-07-16 | 346-201-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2015-07-16 | 346-201-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | HOUSTON | TX |
| 2015-07-08 | 346-312-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | HSTNSUBURB | TX |
| 2015-06-01 | 346-216-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | BAYTOWN | TX |
| 2015-01-27 | 346-216-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX | 7239 | BAYTOWN | TX |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/25/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.