NumberResearch Membership · Data 09/30/2026

Recent prefix assignments

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

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
Rogers Communications Canada Inc. (Wireless) 46
8X8, INC. 43
NEW CINGULAR WIRELESS PCS, LLC - DC 28
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
— 585-428 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-429 0XXX which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-431 0–9 XXXall 10 · 9 holders which blocks → PAETEC ITEL, LLC 829J BROCKPORT NY
— 585-436 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-437 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → VERIZON NEW YORK, INC. 9104 RUSHFORD NY
— 585-438 0–9 XXXall 10 · 9 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K AVON NY
— 585-442 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-451 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ROCHESTER NY
— 585-452 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-453 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-454 8XXX9XXX · 2 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-455 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NY 6959 ROCHESTER NY
— 585-457 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON NEW YORK, INC. 9104 JAVA NY
— 585-458 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-461 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-462 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-463 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-464 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-466 0XXX1XXX2XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → VERIZON NEW YORK, INC. 9104 ANGELICA NY
— 585-467 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-468 1XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 NUNDA NY
— 585-473 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-475 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-476 0XXX1XXX3XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → CITIZENS TELECOMM CO OF NY DBA FRONTIER COMM OF NY 0096 DALTON NY
— 585-477 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-482 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-486 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 TELECOM OF NEW YORK, LP - NY 8473 HENRIETTA NY
— 585-487 0–9 XXXall 10 · 7 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 HENRIETTA NY
— 585-488 0–9 XXXall 10 · 6 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J SPENCERPT NY
— 585-492 6XXX8XXX9XXX · 2 holders which blocks → VERIZON NEW YORK, INC. 9104 ARCADE NY
— 585-493 1XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 CASTILE NY
— 585-494 5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 BERGEN NY
— 585-495 1XXX2XXX4XXX · 3 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 WYOMING NY
— 585-496 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON NEW YORK, INC. 9104 CHAFFEE NY
— 585-502 0–9 XXXall 10 · 7 holders which blocks → PAETEC ITEL, LLC 829J LE ROY NY
— 585-506 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX NY
— 585-520 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ROCHESTER NY
— 585-521 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-525 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-526 2XXX3XXX8XXX · 3 holders which blocks → FRONTIER COMMUNICATIONS OF SENECA GORHAM, INC. 0122 STANLEY NY
— 585-527 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-528 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-529 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-530 0XXX7XXX9XXX which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-533 0XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 RUSH NY
— 585-534 1XXX2XXX3XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ATLANTA NY
— 585-535 1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 5 holders which blocks → VERIZON NEW YORK, INC. 9104 VARYSBURG NY
— 585-537 0–9 XXXall 10 · 6 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - NY 6622 ROCHESTER NY
— 585-538 7XXX8XXX · 2 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 CALEDONIA NY

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/30/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.