NumberResearchThousands-blocks in 308-400
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 308-400 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 308 blocks
Most active assignees, all time — NPA 308
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2025-12-31 | 308-400-0XXX | 0000–0999 | Assigned | ONVOY, LLC - NE | 549E | ORD | NE |
| 2023-02-10 | 308-400-1XXX | 1000–1999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - NE | 3233 | ORD | NE |
| — | 308-400-2XXX | 2000–2999 | Available | ORD | NE | ||
| — | 308-400-3XXX | 3000–3999 | Available | ORD | NE | ||
| 2021-03-04 | 308-400-4XXX | 4000–4999 | Assigned | ONVOY, LLC - NE | 549E | ORD | NE |
| 2021-03-04 | 308-400-5XXX | 5000–5999 | Assigned | ONVOY, LLC - NE | 549E | ORD | NE |
| — | 308-400-6XXX | 6000–6999 | Available | ORD | NE | ||
| — | 308-400-7XXX | 7000–7999 | Available | ORD | NE | ||
| — | 308-400-8XXX | 8000–8999 | Available | ORD | NE | ||
| 2020-10-16 | 308-400-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | ORD | NE |
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.