NumberResearch Membership · Data 09/23/2026

Recent prefix assignments

357 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/23/2026

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. 39
NEW CINGULAR WIRELESS PCS, LLC - IL 28
ONVOY, LLC - CA 27
NEW CINGULAR WIRELESS PCS, LLC - DC 27
ONVOY, LLC - NJ 20
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
— 301-308 not yet reported which blocks → SPOK, INC. 6630 WSNG236Z13 MD
— 301-309 7XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-310 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 LAUREL238 MD
— 301-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 301-312 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-313 1XXX5XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-314 not yet reported which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN4 MD
— 301-315 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-316 8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-317 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-318 none assigned yet which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-319 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-320 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-321 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - MD 876D WSNGTNZN11 MD
— 301-322 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-323 3XXX5XXX8XXX · 2 holders which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 LAUREL236 MD
— 301-324 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-325 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-326 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-329 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - MD 876D ASHTON238 MD
— 301-330 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-331 8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 HAGERSTOWN MD
— 301-332 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN3 MD
— 301-333 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-334 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 OAKLAND MD
— 301-335 none assigned yet which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-336 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-337 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GAITHERSBG MD
— 301-339 3XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J WSNGTNZN10 MD
— 301-340 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-341 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-342 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LXTNPKGRML MD
— 301-343 none assigned yet which blocks → METROPCS, INC. 5562 WSHNGTNZN5 MD
— 301-344 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-345 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-346 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN3 MD
— 301-347 6XXX7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-348 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNGTNZN11 MD
— 301-349 1XXX3XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 POOLESVL MD
— 301-350 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-351 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-352 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-353 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-354 6XXX which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNGTNZN10 MD
— 301-356 0–9 XXXall 10 · 2 holders which blocks → VDL, INC. DBA GLOBAL TELECOM BROKERS - MD 4492 LAUREL236 MD
— 301-358 3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNG236Z15 MD
— 301-359 1XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WESTERNPT MD
— 301-360 5XXX which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-361 not yet reported which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 WSHNGTNZN4 MD
— 301-362 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/23/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.