NumberResearchThousands-blocks in 573-321
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 573-321 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 573 blocks
Most active assignees, all time — NPA 573
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
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Apr 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2003-01-21 | 573-321-0XXX | 0000–0999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 5814 | ADVANCE | MO |
| 2013-04-03 | 573-321-1XXX | 1000–1999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | ADVANCE | MO |
| 2023-01-18 | 573-321-2XXX | 2000–2999 | Assigned | TERRA NOVA TELECOM INC. | 145J | ADVANCE | MO |
| 2008-01-22 | 573-321-3XXX | 3000–3999 | Assigned | ONVOY, LLC - MO | 093F | ADVANCE | MO |
| 2004-12-30 | 573-321-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | ADVANCE | MO |
| 2011-08-19 | 573-321-5XXX | 5000–5999 | Assigned | BANDWIDTH.COM CLEC, LLC - MO | 993E | ADVANCE | MO |
| — | 573-321-6XXX | 6000–6999 | Available | ADVANCE | MO | ||
| 2026-06-10 | 573-321-7XXX | 7000–7999 | Assigned | TERRA NOVA TELECOM INC. | 145J | ADVANCE | MO |
| 2008-06-17 | 573-321-8XXX | 8000–8999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 5814 | ADVANCE | MO |
| 2008-12-18 | 573-321-9XXX | 9000–9999 | Assigned | BANDWIDTH.COM CLEC, LLC - MO | 993E | ADVANCE | MO |
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.