NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

355 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, last 30 days
8X8, INC. 38
ONVOY, LLC - CA 31
NEW CINGULAR WIRELESS PCS, LLC - IL 28
NEW CINGULAR WIRELESS PCS, LLC - DC 26
ONVOY, LLC - NJ 18
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
— 240-516 4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J WSNGTNZN12 MD
— 240-518 0–9 XXXall 10 · 7 holders which blocks → NUSO, LLC 732J WALDORF MD
— 240-519 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 240-524 0XXX1XXX2XXX3XXX6XXX8XXX which blocks → PEERLESS NETWORK OF MARYLAND, LLC 568G LAUREL236 MD
— 240-525 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → PEERLESS NETWORK OF MARYLAND, LLC 568G WSNG236Z15 MD
— 240-526 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PEERLESS NETWORK OF MARYLAND, LLC 568G LEONARDTN MD
— 240-527 0XXX1XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 HAGERSTOWN MD
— 240-528 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 HUGHESVL MD
— 240-529 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 240-530 0–9 XXXall 10 · 6 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WALDORF MD
— 240-533 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSHNGTNZN3 MD
— 240-536 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PEERLESS NETWORK OF MARYLAND, LLC 568G ASHTON236 MD
— 240-539 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → PEERLESS NETWORK OF MARYLAND, LLC 568G WSHNGTNZN4 MD
— 240-541 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 240-542 4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J WSNG236Z13 MD
— 240-544 4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J WSNG236Z14 MD
— 240-545 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J WSNG236Z15 MD
— 240-546 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J WSNGTNZN16 MD
— 240-547 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 LAUREL236 MD
— 240-548 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WSNG236Z14 MD
— 240-553 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNG236Z13 MD
— 240-554 5XXX6XXX7XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LAUREL236 MD
— 240-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MD
— 240-556 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J WSNG236Z14 MD
— 240-558 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J WSNGTNZN11 MD
— 240-559 4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ASHTON236 MD
— 240-568 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 240-573 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNG236Z15 MD
— 240-581 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → PAETEC ITEL, LLC 829J LAUREL236 MD
— 240-582 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 240-597 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → PEERLESS NETWORK OF MARYLAND, LLC 568G GAITHERSBG MD
— 240-599 5XXX6XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNGTNZN10 MD
— 240-601 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 240-602 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 240-603 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 240-604 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 240-605 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 240-606 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 240-607 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WALDORF MD
— 240-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 240-612 0–9 XXXwhole prefix which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 WSHNGTNZN5 MD
— 240-616 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNG236Z13 MD
— 240-619 0–9 XXXall 10 · 6 holders which blocks → COMCAST IP PHONE, LLC 318J WSHNGTNZN5 MD
— 240-620 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNGTNZN10 MD
— 240-621 0–9 XXXall 10 · 7 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F WSNGTNZN11 MD
— 240-624 0XXX1XXX2XXX4XXX6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 240-626 0XXX2XXX · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 FREDERICK MD
— 240-627 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNGTNZN11 MD
— 240-629 8XXX which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 240-631 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD

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.