NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 603-237

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

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The ten 1,000-number thousand-blocks inside prefix 603-237 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
CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 4
3
PAETEC ITEL, LLC 1
LEVEL 3 COMMUNICATIONS, LLC - NH 1
BELL ATLANTIC MOBILE, INC 1
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
— 603-237-0XXX 0000–0999Available COLEBROOK NH
2005-08-16 603-237-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - NH 4017 COLEBROOK NH
2018-02-27 603-237-2XXX 2000–2999Assigned BELL ATLANTIC MOBILE, INC 6386 COLEBROOK NH
— 603-237-3XXX 3000–3999Available COLEBROOK NH
— 603-237-4XXX 4000–4999Reserved CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 5113 COLEBROOK NH
— 603-237-5XXX 5000–5999Reserved CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 5113 COLEBROOK NH
— 603-237-6XXX 6000–6999Available COLEBROOK NH
2007-06-25 603-237-7XXX 7000–7999Assigned PAETEC ITEL, LLC 829J COLEBROOK NH
— 603-237-8XXX 8000–8999Reserved CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 5113 COLEBROOK NH
— 603-237-9XXX 9000–9999Reserved CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 5113 COLEBROOK 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.