NumberResearchThousands-blocks in 501-574
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 501-574 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 501 blocks
Most active assignees, last 30 days — NPA 501
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 501-574-0XXX | 0000–0999 | Reserved | LEVEL 3 COMMUNICATIONS, LLC - AR | 5179 | BENTON | AR |
| 2006-07-11 | 501-574-1XXX | 1000–1999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR | 6805 | BENTON | AR |
| 2007-12-19 | 501-574-2XXX | 2000–2999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR | 6805 | BENTON | AR |
| 2007-04-10 | 501-574-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - AR | 7277 | BENTON | AR |
| 2008-05-12 | 501-574-4XXX | 4000–4999 | Assigned | ONVOY, LLC - AR | 348F | BENTON | AR |
| 2026-09-17 | 501-574-5XXX | 5000–5999 | Assigned | ONVOY, LLC - AR | 348F | BENTON | AR |
| 2016-07-07 | 501-574-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | BENTON | AR |
| 2006-10-11 | 501-574-7XXX | 7000–7999 | Assigned | SOUTHWESTERN BELL | 9533 | BENTON | AR |
| 2008-08-05 | 501-574-8XXX | 8000–8999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR | 6805 | BENTON | AR |
| — | 501-574-9XXX | 9000–9999 | Reserved | LEVEL 3 COMMUNICATIONS, LLC - AR | 5179 | BENTON | AR |
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.