NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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 585
FRONTIER TELEPHONE OF ROCHESTER, INC. 186
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NY 69
ONVOY, LLC- NY 56
NEW CINGULAR WIRELESS PCS, LLC - DC 47
VERIZON NEW YORK, INC. 40
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
— 585-315 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NY 6959 ROCHESTER NY
— 585-317 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - NY 6622 ROCHESTER NY
— 585-318 0–9 XXXall 10 · 7 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K MEDINA NY
— 585-319 0–9 XXXall 10 · 2 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K ROCHESTER NY
— 585-320 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-321 5XXX which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 HENRIETTA NY
— 585-322 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → VERIZON NEW YORK, INC. 9104 BLISS NY
— 585-323 none assigned yet which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-324 0XXX2XXX3XXX5XXX6XXX7XXX9XXX which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-325 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-327 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-328 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-329 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NY 6959 ROCHESTER NY
— 585-330 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NY 6959 ROCHESTER NY
— 585-331 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TC SYSTEMS, INC. - NY 7140 ALBION NY
— 585-333 0XXX2XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-334 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 HENRIETTA NY
— 585-335 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 DANSVILLE NY
— 585-336 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-338 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-339 8XXX which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-340 6XXX7XXX · 2 holders which blocks → LEVEL 3 TELECOM OF NEW YORK, LP - NY 8473 ROCHESTER NY
— 585-341 none assigned yet which blocks → LEVEL 3 TELECOM OF NEW YORK, LP - NY 8473 ROCHESTER NY
— 585-342 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-343 not yet reported which blocks → VERIZON NEW YORK, INC. 9104 BATAVIA NY
— 585-344 not yet reported which blocks → VERIZON NEW YORK, INC. 9104 BATAVIA NY
— 585-345 not yet reported which blocks → VERIZON NEW YORK, INC. 9104 BATAVIA NY
— 585-346 7XXX8XXX · 2 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 LIVONIA NY
— 585-347 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 6 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 W WEBSTER NY
— 585-349 not yet reported which blocks → OGDEN TELCO NY DBA FRONTIER OGDEN TELEPHONE CO 0110 SPENCERPT NY
— 585-350 4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-352 not yet reported which blocks → OGDEN TELCO NY DBA FRONTIER OGDEN TELEPHONE CO 0110 SPENCERPT NY
— 585-355 0–9 XXXall 10 · 2 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K ROCHESTER NY
— 585-356 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NY 6959 BATAVIA NY
— 585-359 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 HENRIETTA NY
— 585-365 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → VERIZON NEW YORK, INC. 9104 BELFAST NY
— 585-366 0–9 XXXall 10 · 6 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K HILTON NY
— 585-367 1XXX4XXX5XXX6XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 HEMLOCK NY
— 585-368 2XXX5XXX8XXX · 2 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-370 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - NY 6622 ROCHESTER NY
— 585-372 9XXX which blocks → PAETEC ITEL, LLC 829J OLEAN NY
— 585-373 8XXX9XXX which blocks → PAETEC ITEL, LLC 829J OLEAN NY
— 585-374 1XXX which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 NAPLES NY
— 585-375 0XXX1XXX6XXX7XXX8XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J OLEAN NY
— 585-376 0XXX1XXX3XXX4XXX5XXX7XXX9XXX · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - NY 997E OLEAN NY
— 585-377 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 FAIRPORT NY
— 585-378 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 OLEAN NY
— 585-379 0XXX1XXX2XXX3XXX4XXX7XXX8XXX · 3 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J OLEAN NY
— 585-381 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 EROCHESTER NY
— 585-382 1XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 LEICESTER NY

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.