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
— 443-264 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
— 443-266 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F GLENWOOD MD
— 443-267 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 DARLINGTON MD
— 443-268 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
— 443-269 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 TOWSON MD
— 443-270 not yet reported which blocks → PAETEC ITEL, LLC 829J GLENBURNIE MD
— 443-272 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 RANDALLSTN MD
— 443-273 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 REISTERSTN MD
— 443-274 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERN MD
— 443-275 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J TOWSON MD
— 443-276 3XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 COLUMBIA MD
— 443-277 none assigned yet which blocks → METROPCS, INC. 5562 SYKESVILLE MD
— 443-279 8XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 TOWSON MD
— 443-280 6XXX8XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 SYKESVILLE MD
— 443-281 3XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 COCKEYSVL MD
— 443-283 not yet reported which blocks → PAETEC ITEL, LLC 829J COLUMBIA MD
— 443-284 0XXX1XXX2XXX3XXX5XXX6XXX7XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WATERLO238 MD
— 443-285 1XXX2XXX3XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 443-286 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 443-287 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 443-288 3XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ELLICOTTCY MD
— 443-290 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 PARKVILLE MD
— 443-291 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 HAMPSTEAD MD
— 443-292 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 CROFTON MD
— 443-293 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WESTMINSTR MD
— 443-294 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F WEST RIVER MD
— 443-295 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 PRINCEFRCK MD
— 443-296 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WATERLO238 MD
— 443-297 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 ARBUTUS MD
— 443-299 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 FALLSTON MD
— 443-300 0XXX1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 SYKESVILLE MD
— 443-302 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 CROFTON MD
— 443-303 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 ABERDEEN MD
— 443-304 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F ARBUTUS MD
— 443-305 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 ARGRGBSNIS MD
— 443-306 2XXX which blocks → METROPCS, INC. 5562 SEVERNA PK MD
— 443-307 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BEL AIR MD
— 443-308 3XXX6XXX7XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SEVERN MD
— 443-309 none assigned yet which blocks → METROPCS, INC. 5562 ELKTON MD
— 443-310 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
— 443-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 443-312 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BRYNPKLNCM MD
— 443-313 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 FORK MD
— 443-315 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 443-316 0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WOODLAWN MD
— 443-317 2XXX3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F CHASE MD
— 443-318 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J COCKEYSVL MD
— 443-319 1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 6 holders which blocks → PAETEC ITEL, LLC 829J COLUMBIA MD
— 443-320 0XXX3XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BALTIMORE MD
— 443-321 not yet reported which blocks → PAETEC ITEL, LLC 829J ANNAPOLIS 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.