NumberResearchThousands-blocks in 517-666
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 517-666 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 517 blocks
Most active assignees, all time — NPA 517
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
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Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2020-10-16 | 517-666-0XXX | 0000–0999 | Assigned | OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC | 2964 | GRANDLEDGE | MI |
| 2019-10-03 | 517-666-1XXX | 1000–1999 | Assigned | COMCAST IP PHONE, LLC | 318J | GRANDLEDGE | MI |
| 2025-05-02 | 517-666-2XXX | 2000–2999 | Assigned | TERRA NOVA TELECOM INC. | 145J | GRANDLEDGE | MI |
| 2022-03-15 | 517-666-3XXX | 3000–3999 | Assigned | TON80 COMMUNICATIONS, LLC | 516J | GRANDLEDGE | MI |
| — | 517-666-4XXX | 4000–4999 | Available | GRANDLEDGE | MI | ||
| 2021-02-03 | 517-666-5XXX | 5000–5999 | Assigned | ONVOY, LLCV - MI | 543C | GRANDLEDGE | MI |
| 2017-11-22 | 517-666-6XXX | 6000–6999 | Assigned | ONVOY, LLCV - MI | 543C | GRANDLEDGE | MI |
| 2021-02-03 | 517-666-7XXX | 7000–7999 | Assigned | ONVOY, LLCV - MI | 543C | GRANDLEDGE | MI |
| — | 517-666-8XXX | 8000–8999 | Available | GRANDLEDGE | MI | ||
| 2026-01-22 | 517-666-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | GRANDLEDGE | MI |
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.