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 251
AT&T ENTERPRISES, LLC 24
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
2024-01-17 251-453-7XXX 7000–7999Assigned AT&T ENTERPRISES, LLC 516C CITRONELLE AL
2016-09-08 251-270-7XXX 7000–7999Assigned AT&T ENTERPRISES, LLC 516C FAIRHOPE AL
2016-07-01 251-525-8XXX 8000–8999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2016-07-01 251-930-0XXX 0000–0999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2016-05-12 251-473-0XXX 0000–0999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2015-04-30 251-345-4XXX 4000–4999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2014-12-03 251-375-1XXX 1000–1999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2014-07-17 251-660-4XXX 4000–4999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2014-02-12 251-307-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2013-10-23 251-260-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C MELVIN AL
2013-04-16 251-408-9XXX 9000–9999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2013-01-24 251-265-0XXX 0000–0999Assigned AT&T ENTERPRISES, LLC 516C MT VERNON AL
2012-11-29 251-369-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C EVERGREEN AL
2012-02-29 251-586-8XXX 8000–8999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2011-10-14 251-697-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C FLOMATON AL
2011-10-14 251-973-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C BELLEFONTN AL
2011-03-21 251-274-7XXX 7000–7999Assigned AT&T ENTERPRISES, LLC 516C MCINTOSH AL
2011-01-14 251-459-0XXX 0000–0999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL
2009-12-23 251-286-7XXX 7000–7999Assigned AT&T ENTERPRISES, LLC 516C BREWTON AL
2009-09-09 251-616-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C CLEAR SPG AL
2009-05-21 251-239-8XXX 8000–8999Assigned AT&T ENTERPRISES, LLC 516C BAYMINETTE AL
2009-05-21 251-517-7XXX 7000–7999Assigned AT&T ENTERPRISES, LLC 516C FAIRHOPE AL
2009-05-21 251-744-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C JACKSON AL
2009-05-11 251-348-7XXX 7000–7999Assigned AT&T ENTERPRISES, LLC 516C MOBILE AL

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.