NumberResearchThousands-blocks in 573-454
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 573-454 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
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2024-02-22 | 573-454-0XXX | 0000–0999 | Assigned | ONVOY SPECTRUM, LLC | 624H | FLAT RIVER | MO |
| 2008-12-19 | 573-454-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - MO | 993E | FLAT RIVER | MO |
| 2003-09-10 | 573-454-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - MO | 993E | FLAT RIVER | MO |
| 2011-12-01 | 573-454-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MO | 7432 | FLAT RIVER | MO |
| 2012-09-04 | 573-454-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - MO | 993E | FLAT RIVER | MO |
| 2014-04-15 | 573-454-5XXX | 5000–5999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 5814 | FLAT RIVER | MO |
| 2013-11-04 | 573-454-6XXX | 6000–6999 | Assigned | IP HORIZON LLC | 515J | FLAT RIVER | MO |
| 2010-02-16 | 573-454-7XXX | 7000–7999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - MO | 7218 | FLAT RIVER | MO |
| 2017-06-01 | 573-454-8XXX | 8000–8999 | Assigned | TELNYX LLC | 073H | FLAT RIVER | MO |
| 2022-09-07 | 573-454-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | FLAT RIVER | MO |
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.