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
— 410-947 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-948 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-949 0XXX4XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 BALTIMORE MD
— 410-950 not yet reported which blocks → MD
— 410-951 not yet reported which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 BALTIMORE MD
— 410-952 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 410-953 9XXX which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-954 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-955 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-956 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-957 7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 POCOMOKE MD
— 410-958 not yet reported which blocks → MD
— 410-959 not yet reported which blocks → MD
— 410-960 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 410-961 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-962 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-963 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-964 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-965 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WOODLAWN MD
— 410-966 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WOODLAWN MD
— 410-967 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 TOWSON MD
— 410-968 5XXX6XXX7XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 CRISFIELD MD
— 410-969 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SEVERN MD
— 410-970 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 SYKESVILLE MD
— 410-971 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-972 1XXX5XXX6XXX7XXX8XXX9XXX which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 ANNAPOLIS MD
— 410-974 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-975 4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-976 not yet reported which blocks → MULTIPLE OCN LISTING MULT BALTIMORE MD
— 410-977 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-978 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-979 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-980 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-981 3XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-983 1XXX3XXX6XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 FORK MD
— 410-984 none assigned yet which blocks → METROPCS, INC. 5562 SYKESVILLE MD
— 410-985 not yet reported which blocks → BALTIMORE-WASHINGTON TELEPHONE (BWT) 8697 WATERLO236 MD
— 410-986 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-987 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SEVERN MD
— 410-988 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-989 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FORK MD
— 410-990 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-991 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-992 2XXX which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-993 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-994 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 EDGEWOOD MD
— 410-995 4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-996 4XXX which blocks → VERIZON MARYLAND, INC. 9212 ELKTON MD
— 410-997 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-998 0XXX which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE 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.