NumberResearchThousands-blocks in 320-558
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 320-558 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 320 blocks
Most active assignees, all time — NPA 320
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 320-558-0XXX | 0000–0999 | Reserved | CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN | 1123 | CLEARWATER | MN |
| 2011-09-20 | 320-558-1XXX | 1000–1999 | Assigned | MIDCONTINENT COMMUNICATIONS - MN | 429A | CLEARWATER | MN |
| — | 320-558-2XXX | 2000–2999 | Reserved | CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN | 1123 | CLEARWATER | MN |
| 2015-05-20 | 320-558-3XXX | 3000–3999 | Assigned | ONVOY, LLC - MN | 184D | CLEARWATER | MN |
| — | 320-558-4XXX | 4000–4999 | Reserved | CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN | 1123 | CLEARWATER | MN |
| — | 320-558-5XXX | 5000–5999 | Reserved | CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN | 1123 | CLEARWATER | MN |
| — | 320-558-6XXX | 6000–6999 | Reserved | CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN | 1123 | CLEARWATER | MN |
| 2008-11-04 | 320-558-7XXX | 7000–7999 | Assigned | BANDWIDTH.COM CLEC, LLC - MN | 980E | CLEARWATER | MN |
| 2016-06-29 | 320-558-8XXX | 8000–8999 | Assigned | ONVOY, LLC - MN | 184D | CLEARWATER | MN |
| — | 320-558-9XXX | 9000–9999 | Reserved | CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN | 1123 | CLEARWATER | MN |
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.