NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 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, all time — NPA 301
VERIZON MARYLAND, INC. 465
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
2014-04-07 301-546 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
2010-03-29 301-400 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
2006-07-20 301-243 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
2006-07-06 301-600 0–9 XXXwhole prefix which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
2005-12-08 301-355 0–9 XXXall 10 · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
2005-03-11 301-892 0–9 XXXall 10 · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
2004-04-22 301-740 0–9 XXXall 10 · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
2003-10-09 301-398 0–9 XXXall 10 · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
2003-06-30 301-796 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
2002-11-20 301-418 0–9 XXXall 10 · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
2002-05-22 301-956 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-203 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-205 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z14 MD
— 301-206 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-208 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-209 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-210 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-212 0XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-214 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-215 0XXX1XXX2XXX3XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-216 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-217 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-218 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-220 6XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-223 0XXX3XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WILLIAMSPT MD
— 301-226 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-227 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-228 0XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-229 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-230 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-231 1XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-234 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-236 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-238 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-239 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-240 none assigned yet which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-241 0XXX2XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 HIGHFIELD MD
— 301-245 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 BITTINGER MD
— 301-246 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 NANJEMOY MD
— 301-248 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-249 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-251 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-253 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 DAMASCS236 MD
— 301-255 9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-258 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-259 1XXX3XXX5XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 TOMPKINSVL MD
— 301-260 4XXX5XXX6XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ASHTON236 MD
— 301-261 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z14 MD
— 301-262 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-263 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 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.