NumberResearchThousands-blocks in 571-636
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 571-636 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 571 blocks
Most active assignees, all time — NPA 571
New assignments by month
Sep 2026
Aug 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2018-07-02 | 571-636-0XXX | 0000–0999 | Assigned | NUSO, LLC | 551G | HAYMARKET | VA |
| 2019-05-15 | 571-636-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - VA | 079F | HAYMARKET | VA |
| 2026-01-13 | 571-636-2XXX | 2000–2999 | Assigned | ONVOY, LLC - VA | 138E | HAYMARKET | VA |
| 2025-07-01 | 571-636-3XXX | 3000–3999 | Assigned | TERRA NOVA TELECOM INC. | 145J | HAYMARKET | VA |
| 2026-02-18 | 571-636-4XXX | 4000–4999 | Assigned | ONVOY, LLC - VA | 138E | HAYMARKET | VA |
| 2025-10-16 | 571-636-5XXX | 5000–5999 | Assigned | TELNYX LLC | 073H | HAYMARKET | VA |
| 2026-03-11 | 571-636-6XXX | 6000–6999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - VA | 4644 | HAYMARKET | VA |
| 2024-11-27 | 571-636-7XXX | 7000–7999 | Assigned | IP HORIZON LLC | 515J | HAYMARKET | VA |
| 2024-11-27 | 571-636-8XXX | 8000–8999 | Assigned | IP HORIZON LLC | 515J | HAYMARKET | VA |
| 2019-06-26 | 571-636-9XXX | 9000–9999 | Assigned | BANDWIDTH.COM CLEC, LLC - VA | 079F | HAYMARKET | VA |
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.