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
— 410-313 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-314 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 ARBUTUS MD
— 410-315 0XXX1XXX2XXX3XXX4XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-316 1XXX6XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 COCKEYSVL MD
— 410-317 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 ARGRGBSNIS MD
— 410-318 9XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-319 0XXX2XXX4XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-320 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 ANNAPOLIS MD
— 410-321 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-322 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BEL AIR MD
— 410-323 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-324 0XXX2XXX3XXX6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-325 0XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-326 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SOLOMONS MD
— 410-327 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-328 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-329 0XXX4XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 COCKEYSVL MD
— 410-330 7XXX8XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CAMBRIDGE MD
— 410-331 not yet reported which blocks → SPOK, INC. 6630 ELKRIDGE MD
— 410-332 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-333 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-334 0XXX1XXX4XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 SALISBURY MD
— 410-335 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CHASE MD
— 410-336 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
— 410-337 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-338 9XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-339 0XXX1XXX2XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-340 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
— 410-341 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SALISBURY MD
— 410-342 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-343 4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 SPARKSGLNC MD
— 410-344 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 CHASE MD
— 410-345 0XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-346 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 SILVER RUN MD
— 410-347 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-348 0XXX1XXX3XXX4XXX6XXX7XXX8XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 STILL POND MD
— 410-349 5XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-350 1XXX4XXX5XXX6XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-351 not yet reported which blocks → SPOK, INC. 6630 BALTIMORE MD
— 410-352 0XXX1XXX2XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 BISHOPVL MD
— 410-353 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-354 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-355 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-356 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-357 1XXX2XXX3XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 PARKTON MD
— 410-358 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-359 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-360 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ARGRGBSNIS MD
— 410-361 0XXX1XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-362 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE 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.