NumberResearchThousands-blocks in 517-443
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 517-443 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 |
|---|---|---|---|---|---|---|---|
| — | 517-443-0XXX | 0000–0999 | Reserved | OGDEN TEL. CO. | 0714 | OGDEN CTR | MI |
| — | 517-443-1XXX | 1000–1999 | Reserved | OGDEN TEL. CO. | 0714 | OGDEN CTR | MI |
| 2011-08-29 | 517-443-2XXX | 2000–2999 | Assigned | DEERFIELD FARMERS' TELEPHONE COMPANY - MI | 558A | OGDEN CTR | MI |
| — | 517-443-3XXX | 3000–3999 | Reserved | OGDEN TEL. CO. | 0714 | OGDEN CTR | MI |
| 2011-09-29 | 517-443-4XXX | 4000–4999 | Assigned | TC3 TELECOM, INC. - MI | 3459 | OGDEN CTR | MI |
| — | 517-443-5XXX | 5000–5999 | Reserved | OGDEN TEL. CO. | 0714 | OGDEN CTR | MI |
| — | 517-443-6XXX | 6000–6999 | Reserved | OGDEN TEL. CO. | 0714 | OGDEN CTR | MI |
| 2020-02-19 | 517-443-7XXX | 7000–7999 | Assigned | PEERLESS NETWORK OF MICHIGAN, LLC - MI | 933G | OGDEN CTR | MI |
| 2023-05-22 | 517-443-8XXX | 8000–8999 | Assigned | BOOST SUBSCRIBERCO L.L.C. | 490J | OGDEN CTR | MI |
| 2013-12-10 | 517-443-9XXX | 9000–9999 | Assigned | PEERLESS NETWORK OF MICHIGAN, LLC - MI | 933G | OGDEN CTR | MI |
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.