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 301
New assignments by month
Sep 2026
Aug 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2019-03-28 | 301-715-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | WSNG236Z15 | MD |
| 2019-03-28 | 301-715-9XXX | 9000–9999 | Assigned | IP HORIZON LLC | 515J | WSNG236Z15 | MD |
| 2019-03-27 | 301-764-8XXX | 8000–8999 | Assigned | IP HORIZON LLC | 515J | WALDORF | MD |
| 2016-05-03 | 301-747-2XXX | 2000–2999 | Assigned | IP HORIZON LLC | 515J | WSHNGTNZN6 | MD |
| 2016-05-02 | 301-242-8XXX | 8000–8999 | Assigned | IP HORIZON LLC | 515J | BRANDYWINE | MD |
| 2016-05-02 | 301-259-9XXX | 9000–9999 | Assigned | IP HORIZON LLC | 515J | TOMPKINSVL | MD |
| 2016-05-02 | 301-391-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | DAMASCS236 | MD |
| 2016-05-02 | 301-430-1XXX | 1000–1999 | Assigned | IP HORIZON LLC | 515J | WSNG236Z14 | MD |
| 2016-05-02 | 301-690-4XXX | 4000–4999 | Assigned | IP HORIZON LLC | 515J | LEONARDTN | MD |
| 2016-05-02 | 301-771-9XXX | 9000–9999 | Assigned | IP HORIZON LLC | 515J | WSHNGTNZN2 | MD |
| 2015-02-19 | 301-274-6XXX | 6000–6999 | Assigned | IP HORIZON LLC | 515J | HUGHESVL | MD |
| 2015-02-19 | 301-349-9XXX | 9000–9999 | Assigned | IP HORIZON LLC | 515J | POOLESVL | MD |
| 2015-02-19 | 301-549-5XXX | 5000–5999 | Assigned | IP HORIZON LLC | 515J | ASHTON236 | MD |
| 2015-02-19 | 301-690-1XXX | 1000–1999 | Assigned | IP HORIZON LLC | 515J | LEONARDTN | MD |
| 2013-08-12 | 301-836-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | WSHNGTNZN5 | MD |
| 2013-08-12 | 301-971-9XXX | 9000–9999 | Assigned | IP HORIZON LLC | 515J | WSHNGTNZN6 | MD |
| 2007-08-17 | 301-444-5XXX | 5000–5999 | Assigned | IP HORIZON LLC | 515J | WSNGTNZN10 | MD |
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.