NumberResearchThousands-blocks in 603-309
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 603-309 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 |
|---|---|---|---|---|---|---|---|
| 2014-04-17 | 603-309-0XXX | 0000–0999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | NEWPORT | NH |
| 2013-10-08 | 603-309-1XXX | 1000–1999 | Assigned | PAETEC ITEL, LLC | 829J | NEWPORT | NH |
| 2016-06-23 | 603-309-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH | 7778 | NEWPORT | NH |
| 2015-02-26 | 603-309-3XXX | 3000–3999 | Assigned | COMCAST IP PHONE, LLC | 318J | NEWPORT | NH |
| 2017-06-12 | 603-309-4XXX | 4000–4999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | NEWPORT | NH |
| 2019-11-25 | 603-309-5XXX | 5000–5999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - NH | 8299 | NEWPORT | NH |
| 2015-11-04 | 603-309-6XXX | 6000–6999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | NEWPORT | NH |
| 2018-07-11 | 603-309-7XXX | 7000–7999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | NEWPORT | NH |
| 2023-05-09 | 603-309-8XXX | 8000–8999 | Assigned | BELL ATLANTIC MOBILE, INC | 6386 | NEWPORT | NH |
| 2022-10-26 | 603-309-9XXX | 9000–9999 | Assigned | TELNYX LLC | 073H | NEWPORT | 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.