NumberResearchThousands-blocks in 203-455
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 203-455 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
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 203-455-0XXX | 0000–0999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT | 7230 | BRIDGEPORT | CT |
| 2005-06-08 | 203-455-1XXX | 1000–1999 | Assigned | OMNIPOINT COMMUNICATIONS, INC. - CT | 6624 | BRIDGEPORT | CT |
| — | 203-455-2XXX | 2000–2999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT | 7230 | BRIDGEPORT | CT |
| — | 203-455-3XXX | 3000–3999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT | 7230 | BRIDGEPORT | CT |
| 2005-10-18 | 203-455-4XXX | 4000–4999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT | 6388 | BRIDGEPORT | CT |
| — | 203-455-5XXX | 5000–5999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT | 7230 | BRIDGEPORT | CT |
| 2007-07-02 | 203-455-6XXX | 6000–6999 | Assigned | OMNIPOINT COMMUNICATIONS, INC. - CT | 6624 | BRIDGEPORT | CT |
| 2005-05-13 | 203-455-7XXX | 7000–7999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | BRIDGEPORT | CT |
| 2005-06-21 | 203-455-8XXX | 8000–8999 | Assigned | OMNIPOINT COMMUNICATIONS, INC. - CT | 6624 | BRIDGEPORT | CT |
| — | 203-455-9XXX | 9000–9999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT | 7230 | 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.