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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 410-471 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-472 5XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 SPARKSGLNC MD
— 410-473 not yet reported which blocks → SPOK, INC. 6630 TOWSON MD
— 410-474 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 PRINCEFRCK MD
— 410-475 not yet reported which blocks → SPOK, INC. 6630 TOWSON MD
— 410-476 0XXX1XXX2XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 TRAPPE MD
— 410-477 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SPARROWSPT MD
— 410-479 6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 DENTON MD
— 410-480 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-481 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-482 0XXX1XXX3XXX4XXX5XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 GREENSBORO MD
— 410-483 8XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-484 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-485 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-486 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-487 1XXX2XXX3XXX4XXX5XXX6XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 GLENBURNIE MD
— 410-488 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-489 1XXX3XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENWOOD MD
— 410-490 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 CENTREVL MD
— 410-491 none assigned yet which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-492 not yet reported which blocks → SPOK, INC. 6630 TOWSON MD
— 410-493 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-494 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-495 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PRINCEFRCK MD
— 410-496 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 RANDALLSTN MD
— 410-497 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → COMCAST IP PHONE, LLC 318J PARKVILLE MD
— 410-498 4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → PAETEC ITEL, LLC 829J COCKEYSVL MD
— 410-499 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-500 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 BALTIMORE MD
— 410-502 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-503 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-504 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-505 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-506 0XXX1XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 ELKTON MD
— 410-507 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-508 0XXX1XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-509 not yet reported which blocks → BALTIMORE-WASHINGTON TELEPHONE (BWT) 8697 WATERLO236 MD
— 410-510 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 FORK MD
— 410-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 410-512 6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-513 4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 PARKVILLE MD
— 410-514 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERN MD
— 410-515 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FORK MD
— 410-516 9XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-517 4XXX6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 REISTERSTN MD
— 410-518 2XXX3XXX4XXX5XXX which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-519 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SEVERN MD
— 410-520 1XXX3XXX4XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 OCEAN CITY MD
— 410-521 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 RANDALLSTN MD
— 410-522 8XXX 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.