NumberResearchThousands-blocks in 660-623
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 660-623 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 660 blocks
Most active assignees, all time — NPA 660
New assignments by month
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 660-623-0XXX | 0000–0999 | Reserved | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | TARKIO | MO |
| 2008-01-07 | 660-623-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | TARKIO | MO |
| — | 660-623-2XXX | 2000–2999 | Available | TARKIO | MO | ||
| — | 660-623-3XXX | 3000–3999 | Available | TARKIO | MO | ||
| — | 660-623-4XXX | 4000–4999 | Available | TARKIO | MO | ||
| — | 660-623-5XXX | 5000–5999 | Available | TARKIO | MO | ||
| 2015-03-19 | 660-623-6XXX | 6000–6999 | Assigned | MIDWEST DATA CENTER, INC. - MO | 454H | TARKIO | MO |
| — | 660-623-7XXX | 7000–7999 | Available | TARKIO | MO | ||
| 2022-01-25 | 660-623-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | TARKIO | MO |
| 2007-01-12 | 660-623-9XXX | 9000–9999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 5814 | TARKIO | MO |
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.