NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 443
PAETEC ITEL, LLC 153
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 121
OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 94
NEW CINGULAR WIRELESS PCS, LLC - DC 71
LEVEL 3 COMMUNICATIONS, LLC - MD 69
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 NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2011-07-18 443-633 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-07-08 443-651 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2011-06-30 443-894 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-06-30 443-913 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-06-29 443-908 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2011-06-01 443-475 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 BALTIMORE MD
2011-05-16 443-289 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 WESTMINSTR MD
2011-04-12 443-897 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
2011-04-06 443-930 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2011-03-29 443-741 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 COLUMBIA MD
2011-03-10 443-842 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2011-02-17 443-358 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → YMAX COMMUNICATIONS CORP. - MD 281E SALISBURY MD
2011-02-16 443-971 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F TANEYTOWN MD
2011-02-04 443-990 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F BALTIMORE MD
2011-02-01 443-208 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-02-01 443-314 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-02-01 443-435 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-02-01 443-882 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-01-31 443-800 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2011-01-06 443-888 0–9 XXXall 10 · 6 holders which blocks → PAETEC ITEL, LLC 829J PRINCEANNE MD
2011-01-06 443-902 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2010-12-13 443-993 0–9 XXXall 10 · 5 holders which blocks → METROPCS, INC. 5562 ELKTON MD
2010-09-27 443-680 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
2010-09-08 443-771 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 PRINCEFRCK MD
2010-08-09 443-863 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2010-07-27 443-853 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2010-07-13 443-821 0–9 XXXall 10 · 5 holders which blocks → METROPCS, INC. 5562 WESTMINSTR MD
2010-06-25 443-826 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2010-06-23 443-488 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
2010-06-15 443-814 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2010-06-09 443-377 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON MD
2010-06-09 443-754 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 SALISBURY MD
2010-06-08 443-750 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2010-05-05 443-887 0–9 XXXwhole prefix which blocks → PAETEC ITEL, LLC 829J CATONSVL MD
2010-03-16 443-464 0–9 XXXall 10 · 4 holders which blocks → PAETEC ITEL, LLC 829J CHURCHVL MD
2010-02-23 443-873 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - MD 876D BALTIMORE MD
2009-10-14 443-635 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
2009-09-08 443-252 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 PERRYVILLE MD
2009-09-08 443-687 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2009-08-13 443-395 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
2009-08-13 443-861 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
2009-07-06 443-721 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2009-07-06 443-924 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
2009-06-08 443-515 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 CAMBRIDGE MD
2009-06-05 443-619 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BEL AIR MD
2009-06-05 443-681 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
2009-05-07 443-547 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WESTMINSTR MD
2009-05-07 443-591 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 GLENBURNIE MD
2009-04-06 443-397 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 SALISBURY MD
2009-03-20 443-467 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.