Thousands-blocks in 603-473

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 603-473 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 3

TWC IP ENABLED SERVICES, LLC 1

TELNYX LLC 1

LEVEL 3 COMMUNICATIONS, LLC - NH 1

IDT AMERICA, CORP. - NH 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

Recent thousands-block assignments
Assigned	Thousands-block	Last 4 digits	Status	Assignee	OCN	Rate center	State
—	603-473-0XXX	0000–0999	Available			MILTON ML	NH
2008-03-20	603-473-1XXX	1000–1999	Assigned	IDT AMERICA, CORP. - NH	314C	MILTON ML	NH
—	603-473-2XXX	2000–2999	Reserved	CONSOLIDATED COMM OF NO. NEW ENGLAND-NH	5113	MILTON ML	NH
2023-09-28	603-473-3XXX	3000–3999	Assigned	BOOST SUBSCRIBERCO L.L.C.	490J	MILTON ML	NH
2004-08-09	603-473-4XXX	4000–4999	Assigned	LEVEL 3 COMMUNICATIONS, LLC - NH	4017	MILTON ML	NH
2001-01-18	603-473-5XXX	5000–5999	Assigned	FREEDOM RING COMMUNICATIONS, LLC	8468	MILTON ML	NH
2024-07-03	603-473-6XXX	6000–6999	Assigned	TELNYX LLC	073H	MILTON ML	NH
2012-07-30	603-473-7XXX	7000–7999	Assigned	TWC IP ENABLED SERVICES, LLC	793K	MILTON ML	NH
—	603-473-8XXX	8000–8999	Reserved	CONSOLIDATED COMM OF NO. NEW ENGLAND-NH	5113	MILTON ML	NH
2014-06-11	603-473-9XXX	9000–9999	Assigned	CONSOLIDATED COMM OF NO. NEW ENGLAND-NH	5113	MILTON ML	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.