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 443
New assignments by month
Sep 2026
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2014-10-06 | 443-951-7XXX | 7000–7999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | MD |
| 2013-09-04 | 443-905-4XXX | 4000–4999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | MD |
| 2013-09-04 | 443-905-5XXX | 5000–5999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | MD |
| 2013-08-23 | 443-905-3XXX | 3000–3999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | MD |
| 2013-07-10 | 443-403-8XXX | 8000–8999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ABERDEEN | MD |
| 2012-03-27 | 443-353-4XXX | 4000–4999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | COCKEYSVL | MD |
| 2011-01-13 | 443-440-8XXX | 8000–8999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | MD |
| 2011-01-13 | 443-440-9XXX | 9000–9999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | MD |
| 2010-10-11 | 443-440-3XXX | 3000–3999 | Assigned | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | ANNAPOLIS | 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.