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 301
VERIZON MARYLAND, INC. 465
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 51
NEW CINGULAR WIRELESS PCS, LLC - DC 47
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 40
TELEPORT COMMUNICATIONS AMERICA, LLC - DC 31
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
2003-10-09 301-398 0–9 XXXall 10 · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
2003-06-30 301-796 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
2002-11-20 301-418 0–9 XXXall 10 · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
2002-08-29 301-703 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 MOUNT AIRY MD
2002-08-13 301-789 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WSHNGTNZN4 MD
2002-07-12 301-857 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CLEAR SPG MD
2002-05-22 301-956 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
2002-05-02 301-876 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 CUMBERLAND MD
2002-02-27 301-760 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSHNGTNZN2 MD
2002-02-27 301-761 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNGTNZN11 MD
2002-02-27 301-768 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSHNGTNZN3 MD
2002-01-09 301-859 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 OAKLAND MD
— 301-203 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-204 5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-205 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z14 MD
— 301-206 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-207 not yet reported which blocks → SPOK, INC. 6630 WSNG236Z13 MD
— 301-208 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-209 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-210 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-211 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 301-212 0XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-213 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-214 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-215 0XXX1XXX2XXX3XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-216 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-217 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-218 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-219 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-220 6XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-221 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-222 3XXX7XXX which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN2 MD
— 301-223 0XXX3XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WILLIAMSPT MD
— 301-224 not yet reported which blocks → SPOK, INC. 6630 WSHNGTNZN2 MD
— 301-226 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-227 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-228 0XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-229 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-230 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-231 1XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-232 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ASHTON236 MD
— 301-233 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-234 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-235 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNGTNZN16 MD
— 301-236 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-237 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-238 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-239 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-240 none assigned yet which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-241 0XXX2XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 HIGHFIELD 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.