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
2019-03-27 443-836-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 443-836-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 443-897-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-21 443-781-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F ARGRGBSNIS MD
2019-03-20 443-272-9XXX 9000–9999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 RANDALLSTN MD
2019-03-20 443-774-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 COLUMBIA MD
2019-03-20 443-833-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F ARBUTUS MD
2019-03-15 443-222-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WORTHINGTN MD
2019-03-15 443-222-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WORTHINGTN MD
2019-03-15 443-337-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SPARROWSPT MD
2019-03-15 443-337-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SPARROWSPT MD
2019-03-15 443-346-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2019-03-15 443-346-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2019-03-15 443-446-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 QUEENSTOWN MD
2019-03-15 443-446-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 QUEENSTOWN MD
2019-03-15 443-446-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 QUEENSTOWN MD
2019-03-15 443-732-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SILVER RUN MD
2019-03-15 443-767-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WORTHINGTN MD
2019-03-14 443-264-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-03-14 443-352-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-03-14 443-352-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-03-14 443-357-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-03-14 443-357-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-03-14 443-367-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COLUMBIA MD
2019-03-14 443-376-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2019-03-14 443-645-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 MILLERSVL MD
2019-03-14 443-647-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 NEWWINDSOR MD
2019-03-14 443-672-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKTON MD
2019-03-14 443-774-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COLUMBIA MD
2019-03-14 443-774-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COLUMBIA MD
2019-03-14 443-774-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COLUMBIA MD
2019-03-14 443-774-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 COLUMBIA MD
2019-03-14 443-843-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 HAVREGRACE MD
2019-03-14 443-936-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ELKRIDGE MD
2019-03-13 443-782-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2019-03-07 443-256-2XXX 2000–2999Assigned METROPCS, INC. 5562 NORTH EAST MD
2019-03-07 443-363-3XXX 3000–3999Assigned METROPCS, INC. 5562 SEVERN MD
2019-03-07 443-587-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 EDGEWOOD MD
2019-03-06 443-381-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 REISTERSTN MD
2019-03-01 443-420-3XXX 3000–3999Assigned COMCAST IP PHONE, LLC 318J ELLICOTTCY MD
2019-03-01 443-788-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F ABERDEEN MD
2019-02-20 443-273-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 REISTERSTN MD
2019-02-14 443-376-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F DUNDALK MD
2019-02-14 443-407-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F DUNDALK MD
2019-02-14 443-879-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F DUNDALK MD
2019-02-11 443-888-2XXX 2000–2999Assigned ONVOY, LLC - MD 876D PRINCEANNE MD
2019-02-11 443-888-3XXX 3000–3999Assigned ONVOY, LLC - MD 876D PRINCEANNE MD
2019-02-07 443-383-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F SILVER RUN MD
2019-02-07 443-383-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F SILVER RUN MD
2019-02-07 443-383-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F SILVER RUN 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.