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 217
ILLINOIS BELL TEL CO 129
FRONTIER NORTH, INC. - IL 114
NEW CINGULAR WIRELESS PCS, LLC - IL 72
LEVEL 3 COMMUNICATIONS, LLC - IL 59
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 51
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
— 217-561 2XXX3XXX4XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 TAYLORVL IL
— 217-562 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 PANA IL
— 217-563 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 NOKOMIS IL
— 217-564 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 IVESDALE IL
— 217-566 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WILLIAMSVL IL
— 217-567 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 TOWER HILL IL
— 217-568 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 GIFFORD IL
— 217-569 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 ARMSTRONG IL
— 217-570 0XXX1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 8 holders which blocks → T-MOBILE USA, INC. 6529 CLINTON IL
— 217-574 0–9 XXXall 10 · 7 holders which blocks → TELNYX LLC 073H FAIRMOUNT IL
— 217-575 2XXX5XXX7XXX · 3 holders which blocks → CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL 1183 WARSAW IL
— 217-577 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 QUINCY IL
— 217-578 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 ATWOOD IL
— 217-580 3XXX4XXX5XXX6XXX · 3 holders which blocks → FRONTIER COMMUNICATIONS OF MT. PULASKI, INC. 1061 MT PULASKI IL
— 217-581 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 CHARLESTON IL
— 217-582 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 OGDEN IL
— 217-583 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 ROYAL IL
— 217-584 0XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MEREDOSIA IL
— 217-585 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 SPRINGFLD IL
— 217-586 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 MAHOMET IL
— 217-587 0XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MANCHESTER IL
— 217-588 0–9 XXXall 10 · 2 holders which blocks → ILLINOIS BELL TEL CO 9329 SPRINGFLD IL
— 217-589 0XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROODHOUSE IL
— 217-590 0XXX3XXX4XXX5XXX6XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MAHOMET IL
— 217-591 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 CHAMPAURBN IL
— 217-592 2XXX6XXX8XXX9XXX · 2 holders which blocks → ILLINOIS BELL TEL CO 9329 QUINCY IL
— 217-593 0XXX2XXX3XXX4XXX5XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CAMP POINT IL
— 217-594 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 WITT IL
— 217-595 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 PENFIELD IL
— 217-597 3XXX4XXX5XXX6XXX7XXX8XXX which blocks → METROPCS, INC. 5562 DANVILLE IL
— 217-598 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 SADORUS IL
— 217-601 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GEORGETOWN IL
— 217-602 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JACKSONVL IL
— 217-603 0XXX1XXX3XXX4XXX7XXX · 2 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F ASHMORE IL
— 217-608 0XXX1XXX2XXX3XXX4XXX5XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 HILLSBORO IL
— 217-609 0XXX1XXX2XXX6XXX9XXX · 4 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F CASEY IL
— 217-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX IL
— 217-619 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 DECATUR IL
— 217-620 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DECATUR IL
— 217-621 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 CHAMPAURBN IL
— 217-622 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 SPRINGFLD IL
— 217-623 not yet reported which blocks → ILLINOIS CONSOLIDATED TEL. CO. 1037 EDINBURG IL
— 217-624 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LOAMI IL
— 217-625 0XXX1XXX6XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PAWNEE IL
— 217-626 0XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PLEASANTPL IL
— 217-627 0XXX1XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 GIRARD IL
— 217-628 0XXX2XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 DIVERNON IL
— 217-629 0XXX1XXX2XXX3XXX4XXX5XXX6XXX · 6 holders which blocks → ILLINOIS BELL TEL CO 9329 RIVERTON IL
— 217-630 0XXX1XXX2XXX3XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 NOKOMIS IL
— 217-632 1XXX6XXX8XXX9XXX · 2 holders which blocks → ILLINOIS BELL TEL CO 9329 PETERSBURG IL

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.