NumberResearchThousands-blocks in 810-644
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 810-644 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 810 blocks
Most active assignees, all time — NPA 810
New assignments by month
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2006-08-24 | 810-644-0XXX | 0000–0999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MI | 6120 | SWARTZ CRK | MI |
| 2019-02-27 | 810-644-1XXX | 1000–1999 | Assigned | ONVOY, LLCV - MI | 543C | SWARTZ CRK | MI |
| 2007-01-17 | 810-644-2XXX | 2000–2999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | SWARTZ CRK | MI |
| 2019-02-27 | 810-644-3XXX | 3000–3999 | Assigned | ONVOY, LLCV - MI | 543C | SWARTZ CRK | MI |
| — | 810-644-4XXX | 4000–4999 | Available | SWARTZ CRK | MI | ||
| 2010-06-02 | 810-644-5XXX | 5000–5999 | Assigned | BANDWIDTH.COM CLEC, LLC - MI | 991E | SWARTZ CRK | MI |
| 2010-09-08 | 810-644-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - MI | 991E | SWARTZ CRK | MI |
| 2008-10-31 | 810-644-7XXX | 7000–7999 | Assigned | COMCAST IP PHONE, LLC | 318J | SWARTZ CRK | MI |
| 2013-02-14 | 810-644-8XXX | 8000–8999 | Assigned | ONVOY, LLCV - MI | 543C | SWARTZ CRK | MI |
| — | 810-644-9XXX | 9000–9999 | Reserved | TELEPORT COMMUNICATIONS AMERICA, LLC - MI | 770E | SWARTZ CRK | 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.