NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

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 410
VERIZON MARYLAND, INC. 510
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 53
NEW CINGULAR WIRELESS PCS, LLC - DC 51
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 45
SPOK, INC. 28
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
— 410-260 0XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-261 0XXX4XXX6XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-262 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-263 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-264 1XXX2XXX6XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-265 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WOODLAWN MD
— 410-266 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-267 3XXX4XXX which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-268 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-269 3XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-270 not yet reported which blocks → REDI-CALL COMMUNICATIONS CO. 6810 SALISBURY MD
— 410-271 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-272 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
— 410-273 3XXX which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
— 410-274 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 410-275 0XXX3XXX4XXX5XXX6XXX7XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 CECILTON MD
— 410-276 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-277 1XXX which blocks → VERIZON MARYLAND, INC. 9212 WOODLAWN MD
— 410-278 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
— 410-279 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-280 7XXX which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-281 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WOODLAWN MD
— 410-282 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 DUNDALK MD
— 410-283 not yet reported which blocks → SPOK, INC. 6630 TOWSON MD
— 410-284 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 DUNDALK MD
— 410-285 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 DUNDALK MD
— 410-286 1XXX4XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 NORTHBEACH MD
— 410-287 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 NORTH EAST MD
— 410-288 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 DUNDALK MD
— 410-289 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 OCEAN CITY MD
— 410-290 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-291 1XXX2XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-292 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-293 not yet reported which blocks → PAETEC ITEL, LLC 829J ANNAPOLIS MD
— 410-294 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-295 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-296 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-297 0XXX1XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
— 410-298 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WOODLAWN MD
— 410-299 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 410-302 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-303 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 410-305 4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 ODENTON MD
— 410-306 5XXX6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ABERDEEN MD
— 410-307 0XXX1XXX3XXX4XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-308 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-309 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-310 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 EASTON MD
— 410-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 410-312 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.