NumberResearch Membership · Data 09/19/2026

Recent thousands-block assignments

0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026

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 443
CORE COMMUNICATIONS, INC.- MD 278
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
2019-07-15 443-337-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SPARROWSPT MD
2019-07-15 443-431-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 RANDALLSTN MD
2019-07-15 443-649-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SPARROWSPT MD
2019-07-15 443-971-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 TANEYTOWN MD
2019-07-15 443-972-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CAMBRIDGE MD
2019-07-15 443-972-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CAMBRIDGE MD
2019-07-12 443-581-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-07-12 443-581-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-07-12 443-582-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHURCHVL MD
2019-07-12 443-582-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHURCHVL MD
2019-07-12 443-686-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 FALLSTON MD
2019-07-12 443-719-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2019-07-12 443-933-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COCKEYSVL MD
2019-07-12 443-933-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COCKEYSVL MD
2019-07-12 443-936-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ELKRIDGE MD
2019-07-12 443-936-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ELKRIDGE MD
2019-06-10 443-576-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 RANDALLSTN MD
2019-06-10 443-686-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 FALLSTON MD
2019-06-10 443-705-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COCKEYSVL MD
2019-06-10 443-773-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BRYNPKLNCM MD
2019-05-22 443-232-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WILLARDS MD
2019-04-18 443-446-1XXX 1000–1999Assigned CORE COMMUNICATIONS, INC.- MD 2593 QUEENSTOWN MD
2019-04-18 443-446-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 QUEENSTOWN MD
2019-04-18 443-446-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 QUEENSTOWN MD
2019-04-16 443-323-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHARPTOWN MD
2019-04-16 443-323-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHARPTOWN MD
2019-04-16 443-497-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SALISBURY MD
2019-04-16 443-513-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2019-04-16 443-513-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2019-04-16 443-513-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2019-04-16 443-665-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 NANTICOKE MD
2019-04-16 443-666-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHESTERTN MD
2019-04-16 443-859-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SALISBURY MD
2019-04-15 443-284-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WATERLO238 MD
2019-04-15 443-284-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WATERLO238 MD
2019-04-15 443-328-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SYKESVILLE MD
2019-04-15 443-348-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WOODLAWN MD
2019-04-15 443-398-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SYKESVILLE MD
2019-04-15 443-516-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SYKESVILLE MD
2019-04-15 443-572-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 GLENBURNIE MD
2019-04-15 443-577-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 GLENBURNIE MD
2019-04-15 443-588-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2019-04-15 443-628-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 GLENBURNIE MD
2019-04-15 443-650-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 REISTERSTN MD
2019-04-15 443-663-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WOODLAWN MD
2019-04-15 443-678-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2019-04-15 443-719-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2019-04-15 443-719-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2019-04-15 443-719-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2019-04-15 443-729-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WOODLAWN MD

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.