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
— 617-509 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 QUINCY MA
— 617-510 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BOSTON MA
— 617-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MA
— 617-512 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
— 617-513 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BOSTON MA
— 617-514 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DORCHESTER MA
— 617-515 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BOSTON MA
— 617-516 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ROXBURY MA
— 617-517 none assigned yet which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
— 617-519 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-520 4XXX which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-521 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-522 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 JAMAICA PL MA
— 617-523 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-524 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 JAMAICA PL MA
— 617-525 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BROOKLINE MA
— 617-526 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-527 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 NEWTON MA
— 617-528 0XXX8XXX9XXX · 2 holders which blocks → TC SYSTEMS, INC. 7135 CAMBRIDGE MA
— 617-529 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 SAUGUS MA
— 617-530 0XXX1XXX · 2 holders which blocks → TC SYSTEMS, INC. 7135 BOSTON MA
— 617-531 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BOSTON MA
— 617-532 not yet reported which blocks → PAETEC ITEL, LLC 829J BOSTON MA
— 617-533 0XXX3XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON NEW ENGLAND INC. 9102 DORCHESTER MA
— 617-534 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-535 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BOSTON MA
— 617-536 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-537 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 QUINCY MA
— 617-538 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WALTHAM MA
— 617-539 2XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → VERIZON NEW ENGLAND INC. 9102 WINTHROP MA
— 617-540 0XXX1XXX2XXX4XXX5XXX · 2 holders which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-541 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 ROXBURY MA
— 617-542 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-543 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BOSTON MA
— 617-545 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E EVERETT MA
— 617-546 4XXX which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E NEWTON MA
— 617-547 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-548 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 SAUGUS MA
— 617-549 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
— 617-550 not yet reported which blocks → MA
— 617-551 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 CAMBRIDGE MA
— 617-552 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 NEWTON MA
— 617-553 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → RCN TELECOM SERVICES, INC. - MA 7619 JAMAICA PL MA
— 617-554 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 XXXXXXXXXX MA
— 617-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MA
— 617-556 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-557 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
— 617-558 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 NEWTON MA
— 617-559 not yet reported which blocks → VERIZON NEW ENGLAND INC. 9102 NEWTON MA
— 617-560 0XXX which blocks → VERIZON NEW ENGLAND INC. 9102 BRIGHTON 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.