NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

17 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, last 30 days — NPA 443
ONVOY, LLC - MD 8
NEW CINGULAR WIRELESS PCS, LLC - DC 4
VERSATEL LLC 1
OPENTACT INC. 1
LEVEL 3 COMMUNICATIONS, LLC - MD 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
2020-01-24 443-946-1XXX 1000–1999Assigned COMCAST IP PHONE, LLC 318J PARKVILLE MD
2020-01-14 443-836-5XXX 5000–5999Assigned ONVOY, LLC - MD 876D BALTIMORE MD
2019-12-31 443-335-5XXX 5000–5999Assigned METROPCS, INC. 5562 BRYNPKLNCM MD
2019-12-20 443-381-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 REISTERSTN MD
2019-12-04 443-698-4XXX 4000–4999Assigned METROPCS, INC. 5562 ODENTON MD
2019-11-20 443-517-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 GLENBURNIE MD
2019-11-07 443-373-4XXX 4000–4999Assigned COMCAST IP PHONE, LLC 318J OCEAN CITY MD
2019-11-05 443-308-6XXX 6000–6999Assigned METROPCS, INC. 5562 SEVERN MD
2019-10-22 443-269-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON MD
2019-10-22 443-269-6XXX 6000–6999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON MD
2019-09-19 443-335-4XXX 4000–4999Assigned METROPCS, INC. 5562 BRYNPKLNCM MD
2019-09-19 443-337-1XXX 1000–1999Assigned METROPCS, INC. 5562 SPARROWSPT MD
2019-09-19 443-381-1XXX 1000–1999Assigned METROPCS, INC. 5562 REISTERSTN MD
2019-09-19 443-704-7XXX 7000–7999Assigned METROPCS, INC. 5562 ODENTON MD
2019-09-18 443-674-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 NORTH EAST MD
2019-09-18 443-705-6XXX 6000–6999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 COCKEYSVL MD
2019-09-18 443-705-7XXX 7000–7999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 COCKEYSVL MD
2019-09-18 443-973-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ELLICOTTCY MD
2019-09-11 443-795-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 SEVERN MD
2019-09-10 443-505-9XXX 9000–9999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 ESSEX MD
2019-09-10 443-774-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 COLUMBIA MD
2019-09-10 443-793-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 PARKVILLE MD
2019-07-31 443-947-6XXX 6000–6999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 PERRYVILLE MD
2019-07-29 443-705-5XXX 5000–5999Assigned COMCAST IP PHONE, LLC 318J COCKEYSVL MD
2019-07-26 443-648-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ESSEX MD
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
2019-07-02 443-628-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 GLENBURNIE MD
2019-06-20 443-256-0XXX 0000–0999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 NORTH EAST MD
2019-06-20 443-402-4XXX 4000–4999Assigned METROPCS, INC. 5562 EDGEWOOD MD
2019-06-20 443-774-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 COLUMBIA MD
2019-06-17 443-216-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 DUNDALK MD
2019-06-10 443-450-7XXX 7000–7999Assigned COMCAST IP PHONE, LLC 318J PIKESVILLE MD
2019-06-10 443-576-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 RANDALLSTN MD
2019-06-10 443-581-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 CHASE MD
2019-06-10 443-686-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 FALLSTON MD

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.