NumberResearch Membership · Data 09/29/2026

Recent prefix assignments

347 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/29/2026

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, last 30 days
8X8, INC. 43
NEW CINGULAR WIRELESS PCS, LLC - DC 28
Rogers Communications Canada Inc. (Wireless) 23
NEW CINGULAR WIRELESS PCS, LLC - IL 23
ONVOY, LLC - CA 19
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
— 585-323 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
— 585-383 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 EROCHESTER NY
— 585-384 1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 COHOCTON NY
— 585-385 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 EROCHESTER NY
— 585-387 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 EROCHESTER NY
— 585-388 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 FAIRPORT NY
— 585-389 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 EROCHESTER NY
— 585-391 0XXX2XXX3XXX4XXX5XXX8XXX9XXX · 5 holders which blocks → PAETEC ITEL, LLC 829J BROCKPORT NY

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/29/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.