Thousands-blocks in 435-666

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 435-666 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 435 blocks

Most active assignees, all time — NPA 435

ONVOY SPECTRUM, LLC 3

ONVOY, LLC - UT 2

TELNYX LLC 1

PEERLESS NETWORK OF UTAH, LLC - UT 1

FRACTEL, LLC 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
2020-06-08	435-666-0XXX	0000–0999	Assigned	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT	6571	PARK CITY	UT
2019-10-03	435-666-1XXX	1000–1999	Assigned	COMCAST IP PHONE, LLC	318J	PARK CITY	UT
2020-09-03	435-666-2XXX	2000–2999	Assigned	TELNYX LLC	073H	PARK CITY	UT
2020-06-18	435-666-3XXX	3000–3999	Assigned	ONVOY SPECTRUM, LLC	624H	PARK CITY	UT
2020-06-18	435-666-4XXX	4000–4999	Assigned	ONVOY SPECTRUM, LLC	624H	PARK CITY	UT
2020-06-18	435-666-5XXX	5000–5999	Assigned	ONVOY SPECTRUM, LLC	624H	PARK CITY	UT
2019-01-25	435-666-6XXX	6000–6999	Assigned	FRACTEL, LLC	965H	PARK CITY	UT
2020-10-30	435-666-7XXX	7000–7999	Assigned	ONVOY, LLC - UT	871E	PARK CITY	UT
2021-02-02	435-666-8XXX	8000–8999	Assigned	ONVOY, LLC - UT	871E	PARK CITY	UT
2020-06-03	435-666-9XXX	9000–9999	Assigned	PEERLESS NETWORK OF UTAH, LLC - UT	526H	PARK CITY	UT

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.