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
2016-05-03 443-663-9XXX 9000–9999Assigned IP HORIZON LLC 515J WOODLAWN MD
2016-05-03 443-733-8XXX 8000–8999Assigned IP HORIZON LLC 515J WATERLO238 MD
2016-05-03 443-753-8XXX 8000–8999Assigned IP HORIZON LLC 515J WATERLO236 MD
2016-05-03 443-775-8XXX 8000–8999Assigned IP HORIZON LLC 515J ANNAPOLIS MD
2016-05-03 443-906-8XXX 8000–8999Assigned IP HORIZON LLC 515J SEVERNA PK MD
2016-04-27 443-652-3XXX 3000–3999Assigned COMCAST IP PHONE, LLC 318J TOWSON MD
2016-04-26 443-495-2XXX 2000–2999Assigned COMCAST IP PHONE, LLC 318J PARKVILLE MD
2016-04-20 443-227-3XXX 3000–3999Assigned HD CARRIER LLC 321J PT DEPOSIT MD
2016-04-20 443-227-6XXX 6000–6999Assigned HD CARRIER LLC 321J PT DEPOSIT MD
2016-04-20 443-227-8XXX 8000–8999Assigned HD CARRIER LLC 321J PT DEPOSIT MD
2016-04-20 443-227-9XXX 9000–9999Assigned HD CARRIER LLC 321J PT DEPOSIT MD
2016-04-20 443-412-6XXX 6000–6999Assigned HD CARRIER LLC 321J CHURCHVL MD
2016-04-20 443-464-3XXX 3000–3999Assigned HD CARRIER LLC 321J CHURCHVL MD
2016-04-20 443-464-6XXX 6000–6999Assigned HD CARRIER LLC 321J CHURCHVL MD
2016-04-20 443-464-7XXX 7000–7999Assigned HD CARRIER LLC 321J CHURCHVL MD
2016-04-20 443-731-7XXX 7000–7999Assigned HD CARRIER LLC 321J PT DEPOSIT MD
2016-04-20 443-747-6XXX 6000–6999Assigned HD CARRIER LLC 321J PT DEPOSIT MD
2016-04-20 443-755-2XXX 2000–2999Assigned HD CARRIER LLC 321J WATERLO238 MD
2016-04-20 443-755-3XXX 3000–3999Assigned HD CARRIER LLC 321J WATERLO238 MD
2016-04-20 443-755-4XXX 4000–4999Assigned HD CARRIER LLC 321J WATERLO238 MD
2016-04-20 443-755-6XXX 6000–6999Assigned HD CARRIER LLC 321J WATERLO238 MD
2016-04-20 443-755-7XXX 7000–7999Assigned HD CARRIER LLC 321J WATERLO238 MD
2016-04-11 443-530-6XXX 6000–6999Assigned COMCAST IP PHONE, LLC 318J DUNDALK MD
2016-04-06 443-274-8XXX 8000–8999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 SEVERN MD
2016-04-06 443-532-2XXX 2000–2999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 PRINCEFRCK MD
2016-04-06 443-775-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
2016-04-06 443-968-8XXX 8000–8999Assigned COMCAST IP PHONE, LLC 318J PRINCEFRCK MD
2016-03-31 443-398-8XXX 8000–8999Assigned COMCAST IP PHONE, LLC 318J SYKESVILLE MD
2016-03-31 443-868-4XXX 4000–4999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 ESSEX MD
2016-03-31 443-868-5XXX 5000–5999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 ESSEX MD
2016-03-31 443-891-5XXX 5000–5999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 GLENBURNIE MD
2016-03-31 443-891-6XXX 6000–6999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 GLENBURNIE MD
2016-03-31 443-891-7XXX 7000–7999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 GLENBURNIE MD
2016-03-31 443-891-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 GLENBURNIE MD
2016-03-31 443-891-9XXX 9000–9999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 GLENBURNIE MD
2016-03-31 443-960-9XXX 9000–9999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 GLENBURNIE MD
2016-03-31 443-972-0XXX 0000–0999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 CAMBRIDGE MD
2016-03-31 443-972-1XXX 1000–1999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 CAMBRIDGE MD
2016-03-29 443-565-4XXX 4000–4999Assigned ONVOY, LLC - MD 876D RANDALLSTN MD
2016-03-29 443-565-6XXX 6000–6999Assigned ONVOY, LLC - MD 876D RANDALLSTN MD
2016-03-29 443-733-4XXX 4000–4999Assigned ONVOY, LLC - MD 876D WATERLO238 MD
2016-03-29 443-733-6XXX 6000–6999Assigned ONVOY, LLC - MD 876D WATERLO238 MD
2016-03-25 443-960-4XXX 4000–4999Assigned COMCAST IP PHONE, LLC 318J GLENBURNIE MD
2016-03-16 443-230-5XXX 5000–5999Assigned ONVOY, LLC - MD 876D ODENTON MD
2016-03-16 443-347-0XXX 0000–0999Assigned ONVOY, LLC - MD 876D CARDIFF MD
2016-03-16 443-407-8XXX 8000–8999Assigned ONVOY, LLC - MD 876D DUNDALK MD
2016-03-16 443-585-3XXX 3000–3999Assigned ONVOY, LLC - MD 876D DARLINGTON MD
2016-03-16 443-585-4XXX 4000–4999Assigned ONVOY, LLC - MD 876D DARLINGTON MD
2016-03-15 443-290-3XXX 3000–3999Assigned ONVOY, LLC - MD 876D PARKVILLE MD
2016-03-15 443-893-3XXX 3000–3999Assigned COMCAST IP PHONE, LLC 318J WOODLAWN 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.