NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 253-617

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 253-617 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 253 blocks

Most active assignees, all time — NPA 253
T-MOBILE USA, INC. 3
LEVEL 3 COMMUNICATIONS, LLC - WA 3
QWEST CORPORATION 1
ONVOY, LLC - WA 1
MCIMETRO ACCESS TRANSMISSION SERVICES 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
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Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
— 253-617-0XXX 0000–0999Reserved LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
2005-09-12 253-617-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
2006-05-15 253-617-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 TACOMA WA
2005-02-18 253-617-3XXX 3000–3999Assigned ONVOY, LLC - WA 483E TACOMA WA
2005-02-18 253-617-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - WA 006F TACOMA WA
2006-11-15 253-617-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 TACOMA WA
2003-10-28 253-617-6XXX 6000–6999Assigned QWEST CORPORATION 9638 TACOMA WA
2005-01-31 253-617-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
2005-12-05 253-617-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 TACOMA WA
2006-01-05 253-617-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 TACOMA WA

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.