NumberResearchThousands-blocks in 603-609
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 603-609 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 603 blocks
Most active assignees, all time — NPA 603
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 603-609-0XXX | 0000–0999 | Reserved | LEVEL 3 COMMUNICATIONS, LLC - NH | 4017 | DOVER | NH |
| 2004-10-13 | 603-609-1XXX | 1000–1999 | Assigned | PAETEC ITEL, LLC | 829J | DOVER | NH |
| — | 603-609-2XXX | 2000–2999 | Available | DOVER | NH | ||
| 2020-11-05 | 603-609-3XXX | 3000–3999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | DOVER | NH |
| 2024-04-09 | 603-609-4XXX | 4000–4999 | Assigned | TERRA NOVA TELECOM INC. | 145J | DOVER | NH |
| 2008-11-06 | 603-609-5XXX | 5000–5999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | DOVER | NH |
| 2008-06-05 | 603-609-6XXX | 6000–6999 | Assigned | FREEDOM RING COMMUNICATIONS, LLC | 8468 | DOVER | NH |
| 2010-09-14 | 603-609-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - NH | 4017 | DOVER | NH |
| 2012-01-24 | 603-609-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | DOVER | NH |
| 2020-09-30 | 603-609-9XXX | 9000–9999 | Assigned | PEERLESS NETWORK OF NEW HAMPSHIRE, LLC - NH | 927H | DOVER | NH |
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.