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
— 301-242 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BRANDYWINE MD
— 301-244 0–9 XXXall 10 · 6 holders which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN3 MD
— 301-245 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 BITTINGER MD
— 301-246 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 NANJEMOY MD
— 301-247 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 LEONARDTN MD
— 301-248 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-249 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-250 0XXX1XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GAITHERSBG MD
— 301-251 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-252 none assigned yet which blocks → METROPCS, INC. 5562 GAITHERSBG MD
— 301-253 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 DAMASCS236 MD
— 301-254 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-255 9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-256 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LAUREL236 MD
— 301-257 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-258 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-259 1XXX3XXX5XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 TOMPKINSVL MD
— 301-260 4XXX5XXX6XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ASHTON236 MD
— 301-261 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z14 MD
— 301-262 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-263 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-264 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 MT SAVAGE MD
— 301-265 2XXX3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-266 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WALDORF MD
— 301-268 none assigned yet which blocks → USCOC OF CUMBERLAND, INC. DBA UNITED STATES CEL MD 4720 CUMBERLAND MD
— 301-270 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-271 8XXX which blocks → VERIZON MARYLAND, INC. 9212 THURMONT MD
— 301-272 0XXX4XXX5XXX7XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN2 MD
— 301-273 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN3 MD
— 301-274 6XXX7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 HUGHESVL MD
— 301-275 none assigned yet which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-276 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN4 MD
— 301-277 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-278 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN5 MD
— 301-279 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-280 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-281 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN6 MD
— 301-282 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-283 1XXX7XXX8XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-284 0XXX3XXX4XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNGTNZN10 MD
— 301-285 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-286 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-287 1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNGTNZN11 MD
— 301-288 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNGTNZN12 MD
— 301-289 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNG236Z13 MD
— 301-290 2XXX3XXX4XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 MECHANCSVL MD
— 301-291 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNG236Z14 MD
— 301-292 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-293 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 MYERSVILLE MD
— 301-294 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 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.