NumberResearchThousands-blocks in 731-574
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 731-574 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 731 blocks
Most active assignees, all time — NPA 731
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2015-04-16 | 731-574-0XXX | 0000–0999 | Assigned | ONVOY, LLC - TN | 525E | JACKSON | TN |
| 2026-07-28 | 731-574-1XXX | 1000–1999 | Assigned | ONVOY, LLC - TN | 525E | JACKSON | TN |
| 2016-08-11 | 731-574-2XXX | 2000–2999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - TN | 114F | JACKSON | TN |
| 2016-12-01 | 731-574-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | JACKSON | TN |
| 2015-05-15 | 731-574-4XXX | 4000–4999 | Assigned | ONVOY, LLC - TN | 525E | JACKSON | TN |
| 2015-05-15 | 731-574-5XXX | 5000–5999 | Assigned | ONVOY, LLC - TN | 525E | JACKSON | TN |
| 2015-05-15 | 731-574-6XXX | 6000–6999 | Assigned | ONVOY, LLC - TN | 525E | JACKSON | TN |
| — | 731-574-7XXX | 7000–7999 | Available | JACKSON | TN | ||
| 2026-07-28 | 731-574-8XXX | 8000–8999 | Assigned | ONVOY, LLC - TN | 525E | JACKSON | TN |
| 2021-07-13 | 731-574-9XXX | 9000–9999 | Assigned | JACKSON ENERGY AUTHORITY - TN | 150G | JACKSON | TN |
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.