NumberResearchThousands-blocks in 203-275
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 203-275 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
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2008-02-07 | 203-275-0XXX | 0000–0999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CT | 4800 | BRIDGEPORT | CT |
| 2008-01-30 | 203-275-1XXX | 1000–1999 | Assigned | SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT | 9147 | BRIDGEPORT | CT |
| 2008-01-30 | 203-275-2XXX | 2000–2999 | Assigned | SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT | 9147 | BRIDGEPORT | CT |
| 2008-01-30 | 203-275-3XXX | 3000–3999 | Assigned | SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT | 9147 | BRIDGEPORT | CT |
| 2008-02-01 | 203-275-4XXX | 4000–4999 | Assigned | SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT | 9147 | BRIDGEPORT | CT |
| 2008-02-08 | 203-275-5XXX | 5000–5999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT | 6388 | BRIDGEPORT | CT |
| 2008-02-08 | 203-275-6XXX | 6000–6999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT | 6388 | BRIDGEPORT | CT |
| 2008-03-25 | 203-275-7XXX | 7000–7999 | Assigned | OMNIPOINT COMMUNICATIONS, INC. - CT | 6624 | BRIDGEPORT | CT |
| 2008-03-13 | 203-275-8XXX | 8000–8999 | Assigned | CSC VOICE, LLC | 612K | BRIDGEPORT | CT |
| 2008-10-30 | 203-275-9XXX | 9000–9999 | Assigned | BANDWIDTH.COM CLEC, LLC - CT | 199F | BRIDGEPORT | CT |
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.