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 617
VERIZON NEW ENGLAND INC. 334
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 71
NEW CINGULAR WIRELESS PCS, LLC - DC 68
PAETEC ITEL, LLC 44
TC SYSTEMS, INC. 41
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
— 617-398 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E CHARLESTN MA
— 617-399 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BOSTON MA
— 617-400 not yet reported which blocks → NORFOLK COUNTY INTERNET, INC. 6083 ROXBURY MA
— 617-401 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
— 617-402 1XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PEERLESS NETWORK OF MASSACHUSETTS, LLC - MA 268F WATERTOWN MA
— 617-403 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 BRIGHTON MA
— 617-405 0–9 XXXall 10 · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 QUINCY MA
— 617-406 7XXX8XXX9XXX · 2 holders which blocks → TC SYSTEMS, INC. 7135 BOSTON MA
— 617-407 not yet reported which blocks → OMNIPOINT MIAMI E LICENSE, LLC 6889 BOSTON MA
— 617-408 0XXX1XXX which blocks → VERIZON NEW ENGLAND INC. 9102 HYDE PARK MA
— 617-411 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MA
— 617-413 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
— 617-414 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-415 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BRIGHTON MA
— 617-418 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 EASTBOSTON MA
— 617-420 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 EVERETT MA
— 617-421 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-422 1XXX9XXX which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-423 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-424 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-425 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-426 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-427 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 ROXBURY MA
— 617-428 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-429 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
— 617-430 8XXX9XXX which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E CAMBRIDGE MA
— 617-431 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → TC SYSTEMS, INC. 7135 NEWTON MA
— 617-432 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BROOKLINE MA
— 617-433 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TC SYSTEMS, INC. 7135 MILTON MA
— 617-434 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-435 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 JAMAICA PL MA
— 617-436 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 DORCHESTER MA
— 617-437 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-438 none assigned yet which blocks → METROPCS, INC. 5562 BOSTON MA
— 617-439 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-440 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → PAETEC ITEL, LLC 829J SOMERVILLE MA
— 617-441 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-442 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 ROXBURY MA
— 617-443 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-444 6XXX7XXX9XXX · 2 holders which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-445 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 ROXBURY MA
— 617-446 3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DORCHESTER MA
— 617-448 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
— 617-449 7XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BOSTON MA
— 617-450 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-451 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-452 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-453 1XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E CAMBRIDGE MA
— 617-454 4XXX5XXX7XXX8XXX · 4 holders which blocks → TC SYSTEMS, INC. 7135 NEWTON MA
— 617-455 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J EASTBOSTON MA

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.