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 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
— 585-473 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
— 585-542 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON NEW YORK, INC. 9104 AKRON NY
— 585-543 0XXX1XXX4XXX6XXX7XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 OLEAN NY
— 585-544 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-545 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J WEBSTER NY
— 585-546 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-547 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → CITIZENS TELECOMM CO OF NY DBA FRONTIER COMM OF NY 0096 DARIEN NY
— 585-548 0XXX1XXX3XXX4XXX5XXX6XXX8XXX · 6 holders which blocks → VERIZON NEW YORK, INC. 9104 BYRON NY
— 585-554 1XXX2XXX7XXX8XXX · 4 holders which blocks → FRONTIER COMMUNICATIONS OF SENECA GORHAM, INC. 0122 RUSHVILLE NY
— 585-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST NY
— 585-563 0–9 XXXall 10 · 3 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K ROCHESTER NY
— 585-567 3XXX7XXX · 2 holders which blocks → CITIZENS TELECOMM CO OF NY DBA FRONTIER COMM OF NY 0096 FILLMORE NY
— 585-568 0–9 XXXall 10 · 6 holders which blocks → PAETEC ITEL, LLC 829J ROCHESTER NY
— 585-571 0–9 XXXall 10 · 7 holders which blocks → PAETEC ITEL, LLC 829J SCOTTSVL NY
— 585-576 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - NY 6622 ROCHESTER NY
— 585-581 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY
— 585-582 0XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 HONEOYEFLS NY
— 585-584 1XXX4XXX6XXX · 2 holders which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 PAVILION NY
— 585-585 not yet reported which blocks → NY
— 585-586 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 EROCHESTER NY
— 585-587 not yet reported which blocks → NY
— 585-588 not yet reported which blocks → FRONTIER TELEPHONE OF ROCHESTER, INC. 0121 ROCHESTER NY

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.