NumberResearchThousands-blocks in 203-571
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 203-571 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 203 blocks
Most active assignees, all time — NPA 203
New assignments by month
Sep 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2025-09-22 | 203-571-0XXX | 0000–0999 | Assigned | TERRA NOVA TELECOM INC. | 145J | WESTPORT | CT |
| 2001-04-27 | 203-571-1XXX | 1000–1999 | Assigned | PAETEC ITEL, LLC | 829J | WESTPORT | CT |
| 2016-01-07 | 203-571-2XXX | 2000–2999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | WESTPORT | CT |
| 2014-04-02 | 203-571-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - CT | 199F | WESTPORT | CT |
| 2014-04-02 | 203-571-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CT | 199F | WESTPORT | CT |
| — | 203-571-5XXX | 5000–5999 | Reserved | AT&T - LOCAL | 7421 | WESTPORT | CT |
| 2006-04-28 | 203-571-6XXX | 6000–6999 | Assigned | PAETEC ITEL, LLC | 829J | WESTPORT | CT |
| 2005-11-03 | 203-571-7XXX | 7000–7999 | Assigned | OMNIPOINT COMMUNICATIONS, INC. - CT | 6624 | WESTPORT | CT |
| 2002-11-21 | 203-571-8XXX | 8000–8999 | Assigned | METROPCS, INC. | 5562 | WESTPORT | CT |
| 2016-01-07 | 203-571-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | WESTPORT | CT |
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.