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 351
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2025-10-29 | 351-204-5XXX | 5000–5999 | Assigned | HD CARRIER LLC | 321J | LAWRENCE | MA |
| 2025-10-29 | 351-204-6XXX | 6000–6999 | Assigned | HD CARRIER LLC | 321J | LAWRENCE | MA |
| 2025-10-29 | 351-239-3XXX | 3000–3999 | Assigned | HD CARRIER LLC | 321J | LOWELL | MA |
| 2025-10-29 | 351-240-7XXX | 7000–7999 | Assigned | HD CARRIER LLC | 321J | LAWRENCE | MA |
| 2016-04-18 | 351-888-4XXX | 4000–4999 | Assigned | HD CARRIER LLC | 321J | MERRIMAC | MA |
| 2016-04-18 | 351-888-5XXX | 5000–5999 | Assigned | HD CARRIER LLC | 321J | MERRIMAC | MA |
| 2016-04-18 | 351-888-6XXX | 6000–6999 | Assigned | HD CARRIER LLC | 321J | MERRIMAC | MA |
| 2016-04-18 | 351-888-7XXX | 7000–7999 | Assigned | HD CARRIER LLC | 321J | MERRIMAC | MA |
| 2016-04-18 | 351-888-9XXX | 9000–9999 | Assigned | HD CARRIER LLC | 321J | MERRIMAC | MA |
| 2016-04-18 | 351-999-1XXX | 1000–1999 | Assigned | HD CARRIER LLC | 321J | MANCHESTER | MA |
| 2016-04-18 | 351-999-2XXX | 2000–2999 | Assigned | HD CARRIER LLC | 321J | MANCHESTER | MA |
| 2016-04-18 | 351-999-3XXX | 3000–3999 | Assigned | HD CARRIER LLC | 321J | MANCHESTER | MA |
| 2016-04-18 | 351-999-4XXX | 4000–4999 | Assigned | HD CARRIER LLC | 321J | MANCHESTER | MA |
| 2016-04-18 | 351-999-5XXX | 5000–5999 | Assigned | HD CARRIER LLC | 321J | MANCHESTER | MA |
| 2016-04-18 | 351-999-6XXX | 6000–6999 | Assigned | HD CARRIER LLC | 321J | MANCHESTER | MA |
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.