NumberResearchThousands-blocks in 401-542
This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/20/2026
The ten 1,000-number thousand-blocks inside prefix 401-542 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 401 blocks
Most active assignees, all time — NPA 401
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 401-542-0XXX | 0000–0999 | Reserved | BANDWIDTH.COM CLEC, LLC - RI | 003F | GREENWICH | RI |
| 2017-02-23 | 401-542-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | GREENWICH | RI |
| — | 401-542-2XXX | 2000–2999 | Reserved | BANDWIDTH.COM CLEC, LLC - RI | 003F | GREENWICH | RI |
| — | 401-542-3XXX | 3000–3999 | Reserved | BANDWIDTH.COM CLEC, LLC - RI | 003F | GREENWICH | RI |
| — | 401-542-4XXX | 4000–4999 | Reserved | BANDWIDTH.COM CLEC, LLC - RI | 003F | GREENWICH | RI |
| 2021-05-04 | 401-542-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | GREENWICH | RI |
| 2021-08-06 | 401-542-6XXX | 6000–6999 | Assigned | TON80 COMMUNICATIONS, LLC | 516J | GREENWICH | RI |
| 2015-11-06 | 401-542-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | GREENWICH | RI |
| — | 401-542-8XXX | 8000–8999 | Reserved | BANDWIDTH.COM CLEC, LLC - RI | 003F | GREENWICH | RI |
| — | 401-542-9XXX | 9000–9999 | Reserved | BANDWIDTH.COM CLEC, LLC - RI | 003F | GREENWICH | RI |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.