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 773
ILLINOIS BELL TEL CO 257
T-MOBILE USA, INC. 169
NEW CINGULAR WIRELESS PCS, LLC - IL 84
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 59
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 38
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
2026-08-19 773-460 0XXX which blocks → ONVOY, LLC 224C CHICGOZN05 IL
2025-10-15 773-448 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC 224C CHICGOZN07 IL
2025-08-14 773-903 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC 224C CHICGOZN06 IL
2025-08-12 773-740 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC 224C CHICGOZN02 IL
2025-04-30 773-204 0–9 XXXall 10 · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 CHICGOZN07 IL
2024-12-19 773-335 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN09 IL
2024-09-03 773-670 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN10 IL
2024-09-03 773-861 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN03 IL
2024-08-28 773-705 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 CHICGOZN04 IL
2023-10-16 773-514 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN09 IL
2023-06-15 773-300 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC 224C CHICGOZN05 IL
2023-06-15 773-500 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC 224C CHICGOZN10 IL
2023-06-08 773-872 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC 224C CHICGOZN04 IL
2023-05-18 773-200 0–9 XXXall 10 · 3 holders which blocks → FIVE9, INC. 598J CHICGOZN02 IL
2023-05-18 773-773 0–9 XXXwhole prefix which blocks → ONVOY SPECTRUM, LLC 624H CHICGOZN09 IL
2022-08-24 773-461 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CHICGOZN02 IL
2021-12-15 773-560 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 CHICGOZN06 IL
2021-07-01 773-352 0–9 XXXwhole prefix which blocks → ONVOY, LLC 224C CHICGOZN03 IL
2020-05-01 773-923 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN03 IL
2020-02-05 773-232 0–9 XXXwhole prefix which blocks → ONVOY, LLC 224C CHICGOZN10 IL
2019-08-19 773-900 0–9 XXXall 10 · 4 holders which blocks → FRACTEL, LLC 965H CHICGOZN03 IL
2019-08-07 773-207 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC 224C CHICGOZN10 IL
2019-01-31 773-692 0–9 XXXwhole prefix which blocks → ONVOY, LLC 224C CHICGOZN04 IL
2015-11-23 773-839 0–9 XXXwhole prefix which blocks → ONVOY, LLC 224C CHICGOZN04 IL
2011-09-08 773-231 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN07 IL
2011-08-23 773-492 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E CHICGOZN08 IL
2011-05-20 773-666 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E CHICGOZN04 IL
2011-02-24 773-949 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CHICGOZN03 IL
2011-02-18 773-993 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CHICGOZN03 IL
2011-01-05 773-644 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 CHICGOZN02 IL
2010-11-01 773-796 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN02 IL
2010-09-03 773-943 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CHICGOZN02 IL
2010-08-31 773-916 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CHICGOZN06 IL
2010-06-16 773-245 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E CHICGOZN08 IL
2009-07-01 773-554 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CHICGOZN03 IL
2009-06-26 773-234 0–9 XXXwhole prefix which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E CHICGOZN06 IL
2009-06-26 773-236 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CHICGOZN07 IL
2009-06-25 773-800 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CHICGOZN02 IL
2009-06-25 773-888 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E CHICGOZN04 IL
2009-06-08 773-669 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E CHICGOZN05 IL
2009-06-04 773-270 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 CHICGOZN04 IL
2009-05-19 773-217 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN09 IL
2009-05-15 773-901 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN10 IL
2009-05-15 773-970 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN10 IL
2009-05-15 773-998 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN10 IL
2009-05-15 773-999 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN05 IL
2009-03-31 773-815 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN03 IL
2009-03-23 773-812 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN03 IL
2009-03-10 773-397 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN03 IL
2009-03-10 773-630 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHICGOZN03 IL

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.