NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/20/2026

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

Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.

Most active assignees, all time — NPA 657
COMCAST PHONE OF CALIFORNIA, LLC 10
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
2019-06-25 657-660-5XXX 5000–5999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA
2017-10-03 657-314-9XXX 9000–9999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SILVERADO CA
2017-09-26 657-720-1XXX 1000–1999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA
2017-08-01 657-720-2XXX 2000–2999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA
2017-08-01 657-720-3XXX 3000–3999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA
2017-08-01 657-720-4XXX 4000–4999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA
2017-08-01 657-720-5XXX 5000–5999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA
2015-06-19 657-363-1XXX 1000–1999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L YORBALINDA CA
2010-01-12 657-200-7XXX 7000–7999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L WESTMINSTR CA
2008-06-12 657-859-6XXX 6000–6999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA ANA CA

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.