NumberResearchThousands-blocks in 231-916
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 231-916 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 231 blocks
Most active assignees, all time — NPA 231
New assignments by month
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 231-916-0XXX | 0000–0999 | Reserved | LEVEL 3 COMMUNICATIONS, LLC - MI | 6120 | MANCELONA | MI |
| 2005-01-12 | 231-916-1XXX | 1000–1999 | Assigned | ACD TELECOM, INC. - MI | 3535 | MANCELONA | MI |
| 2007-01-23 | 231-916-2XXX | 2000–2999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | MANCELONA | MI |
| 2012-05-04 | 231-916-3XXX | 3000–3999 | Assigned | ONVOY, LLCV - MI | 543C | MANCELONA | MI |
| 2004-06-22 | 231-916-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MI | 6120 | MANCELONA | MI |
| 2012-12-05 | 231-916-5XXX | 5000–5999 | Assigned | ONVOY, LLCV - MI | 543C | MANCELONA | MI |
| 2004-01-12 | 231-916-6XXX | 6000–6999 | Assigned | PAETEC ITEL, LLC | 829J | MANCELONA | MI |
| 2013-01-28 | 231-916-7XXX | 7000–7999 | Assigned | AT&T ENTERPRISES, LLC | 516C | MANCELONA | MI |
| — | 231-916-8XXX | 8000–8999 | Available | MANCELONA | MI | ||
| — | 231-916-9XXX | 9000–9999 | Reserved | LEVEL 3 COMMUNICATIONS, LLC - MI | 6120 | MANCELONA | 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.