NumberResearchThousands-blocks in 603-552
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 603-552 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
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2011-04-04 | 603-552-0XXX | 0000–0999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | DERRY | NH |
| 2001-08-29 | 603-552-1XXX | 1000–1999 | Assigned | PAETEC ITEL, LLC | 829J | DERRY | NH |
| 2003-10-06 | 603-552-2XXX | 2000–2999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - NH | 8299 | DERRY | NH |
| 2010-11-03 | 603-552-3XXX | 3000–3999 | Assigned | COMCAST IP PHONE, LLC | 318J | DERRY | NH |
| 2002-08-28 | 603-552-4XXX | 4000–4999 | Assigned | OTEL TELEKOM, INC. - NH | 9827 | DERRY | NH |
| 2004-09-15 | 603-552-5XXX | 5000–5999 | Assigned | PAETEC ITEL, LLC | 829J | DERRY | NH |
| 2023-05-03 | 603-552-6XXX | 6000–6999 | Assigned | ONVOY, LLC - NH | 637E | DERRY | NH |
| 2011-05-05 | 603-552-7XXX | 7000–7999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | DERRY | NH |
| 2013-09-05 | 603-552-8XXX | 8000–8999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | DERRY | NH |
| — | 603-552-9XXX | 9000–9999 | Reserved | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH | 7778 | DERRY | NH |
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.