NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

371 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)

Which carriers received which NPA-NXX prefixes, and where. Assignments are initial assignments from NANPA records — because of number portability, the current serving carrier of individual numbers may differ. For finer-grained activity, see the thousands-block view above.

Most active assignees, last 30 days
8X8, INC. 38
ONVOY, LLC - CA 31
NEW CINGULAR WIRELESS PCS, LLC - IL 31
NEW CINGULAR WIRELESS PCS, LLC - DC 30
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-NXXAssigneeOCNRate centerState
773-321 LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN06 IL
773-322 T-MOBILE USA, INC. 6529 CHICGOZN07 IL
773-324 ILLINOIS BELL TEL CO 9329 CHICGOZN07 IL
773-325 ILLINOIS BELL TEL CO 9329 CHICGOZN04 IL
773-326 LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN07 IL
773-327 ILLINOIS BELL TEL CO 9329 CHICGOZN04 IL
773-328 FIRST COMMUNICATIONS, LLC 460K CHICGOZN04 IL
773-329 TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 CHICGOZN03 IL
773-330 NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN01 IL
773-331 T-MOBILE USA, INC. 6529 CHICGOZN03 IL
773-332 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 CHICGOZN03 IL
773-334 ILLINOIS BELL TEL CO 9329 CHICGOZN02 IL
773-336 FIRST COMMUNICATIONS, LLC 460K CHICGOZN09 IL
773-337 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN11 IL
773-338 ILLINOIS BELL TEL CO 9329 CHICGOZN02 IL
773-339 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 CHICGOZN01 IL
773-340 ONVOY, LLC 224C CHICGOZN08 IL
773-341 FIRST COMMUNICATIONS, LLC 460K CHICGOZN10 IL
773-342 ILLINOIS BELL TEL CO 9329 CHICGOZN04 IL
773-343 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 CHICGOZN01 IL
773-344 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN10 IL
773-345 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN05 IL
773-346 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN06 IL
773-347 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN07 IL
773-348 ILLINOIS BELL TEL CO 9329 CHICGOZN04 IL
773-349 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN08 IL
773-350 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 CHICGOZN01 IL
773-351 NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN01 IL
773-353 LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN03 IL
773-354 T-MOBILE USA, INC. 6529 CHICGOZN01 IL
773-356 ILLINOIS BELL TEL CO 9329 CHICGOZN09 IL
773-357 FIRST COMMUNICATIONS, LLC 460K CHICGOZN11 IL
773-358 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN07 IL
773-359 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN09 IL
773-360 LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN04 IL
773-361 ILLINOIS BELL TEL CO 9329 CHICGOZN07 IL
773-362 PAETEC ITEL, LLC 829J CHICGOZN08 IL
773-363 ILLINOIS BELL TEL CO 9329 CHICGOZN07 IL
773-365 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CHICGOZN04 IL
773-368 T-MOBILE USA, INC. 6529 CHICGOZN03 IL
773-369 NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN01 IL
773-370 T-MOBILE USA, INC. 6529 CHICGOZN01 IL
773-371 ILLINOIS BELL TEL CO 9329 CHICGOZN07 IL
773-373 ILLINOIS BELL TEL CO 9329 CHICGOZN07 IL
773-374 ILLINOIS BELL TEL CO 9329 CHICGOZN09 IL
773-375 ILLINOIS BELL TEL CO 9329 CHICGOZN09 IL
773-376 ILLINOIS BELL TEL CO 9329 CHICGOZN06 IL
773-377 TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 CHICGOZN11 IL
773-378 ILLINOIS BELL TEL CO 9329 CHICGOZN05 IL
773-379 ILLINOIS BELL TEL CO 9329 CHICGOZN05 IL

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.