NumberResearchThousands-blocks in 517-283
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 517-283 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
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 517-283-0XXX | 0000–0999 | Available | READING | MI | ||
| — | 517-283-1XXX | 1000–1999 | Reserved | FRONTIER NORTH, INC. - MI | 0695 | READING | MI |
| — | 517-283-2XXX | 2000–2999 | Reserved | FRONTIER NORTH, INC. - MI | 0695 | READING | MI |
| — | 517-283-3XXX | 3000–3999 | Reserved | FRONTIER NORTH, INC. - MI | 0695 | READING | MI |
| — | 517-283-4XXX | 4000–4999 | Available | READING | MI | ||
| 2007-02-08 | 517-283-5XXX | 5000–5999 | Assigned | ONVOY, LLCV - MI | 543C | READING | MI |
| 2006-10-12 | 517-283-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MI | 6120 | READING | MI |
| 2025-05-07 | 517-283-7XXX | 7000–7999 | Assigned | TERRA NOVA TELECOM INC. | 145J | READING | MI |
| 2003-02-13 | 517-283-8XXX | 8000–8999 | Assigned | 123.NET, LLC | 2550 | READING | MI |
| 2026-03-05 | 517-283-9XXX | 9000–9999 | Assigned | TERRA NOVA TELECOM INC. | 145J | READING | 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.