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 240
OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 117
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 85
NEW CINGULAR WIRELESS PCS, LLC - DC 69
PAETEC ITEL, LLC 63
LEVEL 3 COMMUNICATIONS, LLC - MD 59
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
2006-09-13 240-595 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
2006-08-09 240-577 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 LEONARDTN MD
2006-08-08 240-512 0–9 XXXall 10 · 6 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WSNG238Z13 MD
2006-07-25 240-543 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN2 MD
2006-07-12 240-567 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
2006-06-12 240-357 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 FREDERICK MD
2006-06-12 240-688 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
2006-05-19 240-654 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 GAITHERSBG MD
2006-03-29 240-520 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 HAGERSTOWN MD
2006-03-09 240-345 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 ASHTON238 MD
2006-01-05 240-755 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J LAUREL238 MD
2005-12-30 240-565 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 LAUREL238 MD
2005-12-30 240-575 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 FREDERICK MD
2005-05-27 240-821 0–9 XXXall 10 · 4 holders which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN3 MD
2005-05-20 240-477 0–9 XXXall 10 · 3 holders which blocks → PAETEC ITEL, LLC 829J GAITHERSBG MD
2005-05-06 240-750 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 GAITHERSBG MD
2005-04-22 240-454 0–9 XXXall 10 · 5 holders which blocks → PAETEC ITEL, LLC 829J GAITHERSBG MD
2004-12-13 240-394 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 MOUNT AIRY MD
2004-11-22 240-770 0–9 XXXall 10 · 3 holders which blocks → COMCAST IP PHONE, LLC 318J WSHNGTNZN4 MD
2004-11-01 240-284 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 FROSTBURG MD
2004-11-01 240-288 0–9 XXXall 10 · 6 holders which blocks → COMCAST IP PHONE, LLC 318J THURMONT MD
2004-07-27 240-405 0–9 XXXall 10 · 4 holders which blocks → PAETEC ITEL, LLC 829J FREDERICK MD
2004-07-27 240-478 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN3 MD
2004-05-04 240-276 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
2003-10-30 240-681 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J BRANDYWINE MD
2003-07-23 240-205 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSNGTNZN10 MD
2003-03-27 240-307 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F EMMITSBURG MD
2002-11-04 240-388 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 GAITHERSBG MD
2002-10-18 240-277 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN2 MD
2002-10-18 240-367 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 FREDERICK MD
2002-10-15 240-291 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 HAGERSTOWN MD
2002-10-15 240-344 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 FREDERICK MD
2002-09-17 240-286 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN2 MD
2002-07-03 240-304 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN5 MD
2002-07-03 240-398 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
2002-06-11 240-566 0–9 XXXall 10 · 7 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
2002-05-16 240-643 1XXX2XXX3XXX4XXX5XXX7XXX8XXX which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
2002-05-15 240-422 1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 FREDERICK MD
2002-01-09 240-506 7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSNGTNZN10 MD
2001-12-12 240-522 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → METROPCS, INC. 5562 CUMBERLAND MD
2001-11-12 240-418 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN2 MD
2001-10-31 240-505 not yet reported which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
2001-10-25 240-426 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN2 MD
2001-10-08 240-501 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
2001-08-09 240-446 5XXX7XXX8XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 FREDERICK MD
2001-08-09 240-925 7XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 LEONARDTN MD
2001-07-10 240-466 0–9 XXXall 10 · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 MECHANCSVL MD
2001-06-20 240-455 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN5 MD
2001-06-20 240-515 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
2001-06-14 240-580 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 3 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 CUMBERLAND MD

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.