NumberResearchThousands-blocks in 351-444
This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/19/2026
The ten 1,000-number thousand-blocks inside prefix 351-444 and who was initially assigned each. Under pooling these blocks often belong to different carriers — the single prefix-level “assignee” is usually just the pool / code holder, not who holds the numbers. ← all 351 blocks
Most active assignees, all time — NPA 351
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 |
|---|---|---|---|---|---|---|---|
| 2016-06-01 | 351-444-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | IPSWICH | MA |
| 2017-04-18 | 351-444-1XXX | 1000–1999 | Assigned | TELNYX LLC | 073H | IPSWICH | MA |
| 2017-12-11 | 351-444-2XXX | 2000–2999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA | 6387 | IPSWICH | MA |
| 2019-01-22 | 351-444-3XXX | 3000–3999 | Assigned | ONVOY, LLC - MA | 892D | IPSWICH | MA |
| 2016-03-31 | 351-444-4XXX | 4000–4999 | Assigned | ONVOY, LLC - MA | 892D | IPSWICH | MA |
| 2019-01-22 | 351-444-5XXX | 5000–5999 | Assigned | ONVOY, LLC - MA | 892D | IPSWICH | MA |
| 2019-06-05 | 351-444-6XXX | 6000–6999 | Assigned | COMCAST IP PHONE, LLC | 318J | IPSWICH | MA |
| 2022-05-16 | 351-444-7XXX | 7000–7999 | Assigned | OMNIPOINT MIAMI E LICENSE, LLC | 6889 | IPSWICH | MA |
| 2018-09-07 | 351-444-8XXX | 8000–8999 | Assigned | OMNIPOINT MIAMI E LICENSE, LLC | 6889 | IPSWICH | MA |
| 2020-03-19 | 351-444-9XXX | 9000–9999 | Assigned | ONVOY, LLC - MA | 892D | IPSWICH | 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.