NumberResearchThousands-blocks in 605-401
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 605-401 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 605 blocks
Most active assignees, all time — NPA 605
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 |
|---|---|---|---|---|---|---|---|
| 2021-06-08 | 605-401-0XXX | 0000–0999 | Assigned | ONVOY, LLC - SD | 162G | SIOUX FLS | SD |
| 2021-03-02 | 605-401-1XXX | 1000–1999 | Assigned | IP HORIZON LLC | 515J | SIOUX FLS | SD |
| 2021-06-08 | 605-401-2XXX | 2000–2999 | Assigned | ONVOY, LLC - SD | 162G | SIOUX FLS | SD |
| 2021-06-08 | 605-401-3XXX | 3000–3999 | Assigned | ONVOY, LLC - SD | 162G | SIOUX FLS | SD |
| 2021-06-08 | 605-401-4XXX | 4000–4999 | Assigned | ONVOY, LLC - SD | 162G | SIOUX FLS | SD |
| 2021-11-22 | 605-401-5XXX | 5000–5999 | Assigned | TELNYX LLC | 073H | SIOUX FLS | SD |
| 2021-12-29 | 605-401-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - SD | 5180 | SIOUX FLS | SD |
| 2021-07-28 | 605-401-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - SD | 5180 | SIOUX FLS | SD |
| 2022-11-07 | 605-401-8XXX | 8000–8999 | Assigned | ONVOY, LLC - SD | 162G | SIOUX FLS | SD |
| 2023-06-28 | 605-401-9XXX | 9000–9999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - SD | 6569 | SIOUX FLS | SD |
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.