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 301
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 |
|---|---|---|---|---|---|---|---|
| 2023-02-07 | 301-726-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | KITZMILLER | MD |
| 2019-09-03 | 301-835-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | FREDERICK | MD |
| 2018-10-19 | 301-837-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNG236Z13 | MD |
| 2018-10-19 | 301-837-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNG236Z13 | MD |
| 2018-10-19 | 301-837-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNG236Z13 | MD |
| 2017-11-13 | 301-913-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2017-11-13 | 301-913-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2017-11-13 | 301-913-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2017-11-13 | 301-913-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2017-11-13 | 301-913-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2017-06-23 | 301-348-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-321-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-761-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-822-0XXX | 0000–0999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-822-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-822-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-822-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-822-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-945-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-945-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-08-22 | 301-945-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2016-01-13 | 301-945-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2015-10-13 | 301-269-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-08-21 | 301-235-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN16 | MD |
| 2015-07-09 | 301-732-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | FREDERICK | MD |
| 2015-05-18 | 301-269-0XXX | 0000–0999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-05-18 | 301-269-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-05-18 | 301-269-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-05-06 | 301-945-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2015-04-17 | 301-269-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-03-06 | 301-269-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-03-06 | 301-269-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-03-06 | 301-269-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2015-03-05 | 301-837-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNG236Z13 | MD |
| 2015-01-05 | 301-242-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | BRANDYWINE | MD |
| 2014-11-13 | 301-269-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2014-10-29 | 301-761-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2014-09-29 | 301-761-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNGTNZN11 | MD |
| 2014-02-11 | 301-547-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2011-08-17 | 301-289-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSNG236Z13 | MD |
| 2011-07-29 | 301-200-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | INDIANHEAD | MD |
| 2011-04-13 | 301-500-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2011-04-13 | 301-500-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2011-04-06 | 301-500-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN2 | MD |
| 2011-01-13 | 301-836-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN5 | MD |
| 2010-12-17 | 301-250-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | GAITHERSBG | MD |
| 2009-08-24 | 301-501-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | OAKLAND | MD |
| 2009-08-24 | 301-969-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BRUNSWICK | MD |
| 2009-08-21 | 301-304-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | WALKERSVL | MD |
| 2009-07-29 | 301-686-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WSHNGTNZN6 | MD |
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.