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 501
SOUTHWESTERN BELL 165
NEW CINGULAR WIRELESS PCS, LLC - IL 86
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 54
LEVEL 3 COMMUNICATIONS, LLC - AR 48
T-MOBILE USA, INC. 42
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
2026-08-12 501-610 0XXX1XXX · 2 holders which blocks → ONVOY, LLC - AR 348F CABOT AR
2026-06-12 501-608 1XXX2XXX which blocks → IP HORIZON LLC 515J SYVNHLSHWD AR
2026-06-03 501-597 0XXX1XXX2XXX6XXX8XXX · 3 holders which blocks → IP HORIZON LLC 515J HOTSPRINGS AR
2026-06-03 501-598 1XXX2XXX which blocks → IP HORIZON LLC 515J PALARM AR
2026-06-01 501-595 0XXX1XXX2XXX5XXX · 3 holders which blocks → IP HORIZON LLC 515J BRYANTCGVL AR
2026-03-30 501-738 8XXX which blocks → AHOI LLC 883K LITTLEROCK AR
2025-12-15 501-587 0XXX1XXX8XXX · 3 holders which blocks → E. RITTER COMMUNICATIONS, LLC 128L LITTLEROCK AR
2025-12-12 501-586 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ONVOY, LLC - AR 348F CONWAY AR
2025-12-05 501-591 0XXX1XXX2XXX3XXX4XXX7XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 BEEBE AR
2025-11-17 501-583 0XXX4XXX · 2 holders which blocks → WAVENATION, LLC 700J LITTLEROCK AR
2025-11-04 501-582 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ONVOY, LLC - AR 348F BENTON AR
2025-09-11 501-867 5XXX which blocks → ONVOY, LLC - AR 348F MAUMELLE AR
2025-04-16 501-579 0XXX1XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SPRINGLAKE AR
2025-03-13 501-578 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - AR 348F FERNDALE AR
2025-02-12 501-560 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - AR 348F JACKSONVL AR
2025-01-13 501-576 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CONWAY AR
2024-12-30 501-573 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CABOT AR
2024-10-31 501-714 0XXX which blocks → TWILIO INTERNATIONAL, INC. 506J GREENBRIER AR
2024-10-16 501-383 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - AR 196F SEARCY AR
2024-02-20 501-540 0XXX5XXX · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H MCRAE AR
2024-02-20 501-572 0XXX1XXX · 2 holders which blocks → BOOST SUBSCRIBERCO L.L.C. 490J ENOLA AR
2024-02-16 501-564 0–9 XXXall 10 · 4 holders which blocks → IP HORIZON LLC 515J SYVNHLSHWD AR
2024-01-31 501-870 0XXX1XXX · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H MORGANTON AR
2023-12-20 501-559 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 BENTON AR
2023-11-06 501-561 0–9 XXXall 10 · 5 holders which blocks → CALLWORKS CORPORATION 475J LITTLEROCK AR
2023-10-17 501-549 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 PALARM AR
2023-10-09 501-546 4XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 FAIRFLD BY AR
2023-09-28 501-544 4XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 SHIRLEY AR
2023-06-12 501-536 0–9 XXXall 10 · 7 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 CONWAY AR
2023-05-16 501-532 0XXX1XXX3XXX4XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 JESSIEVL AR
2023-01-20 501-531 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - AR 196F HOTSPRINGS AR
2023-01-11 501-571 0XXX1XXX5XXX · 2 holders which blocks → ONVOY, LLC - AR 348F WYE AR
2022-10-03 501-528 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 MALVERN AR
2022-09-27 501-501 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AR 348F HOTSPRINGS AR
2022-09-21 501-480 0–9 XXXall 10 · 3 holders which blocks → NUSO, LLC 732J LITTLEROCK AR
2022-09-21 501-527 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → PAETEC ITEL, LLC 829J LITTLEROCK AR
2022-05-12 501-946 0–9 XXXall 10 · 4 holders which blocks → FRACTEL, LLC 965H BENTON AR
2022-02-24 501-535 0XXX5XXX6XXX · 3 holders which blocks → TON80 COMMUNICATIONS, LLC 516J BALD KNOB AR
2022-02-15 501-782 7XXX which blocks → TON80 COMMUNICATIONS, LLC 516J GRIFFITHVL AR
2022-02-15 501-942 0XXX1XXX2XXX3XXX4XXX6XXX7XXX · 5 holders which blocks → TON80 COMMUNICATIONS, LLC 516J SCOTT AR
2022-02-07 501-746 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → TON80 COMMUNICATIONS, LLC 516J BRYANTCGVL AR
2022-01-13 501-832 0XXX1XXX2XXX4XXX5XXX · 3 holders which blocks → TON80 COMMUNICATIONS, LLC 516J GREERSFRRY AR
2022-01-13 501-866 2XXX6XXX · 2 holders which blocks → TON80 COMMUNICATIONS, LLC 516J CASA AR
2022-01-12 501-524 0XXX1XXX2XXX3XXX6XXX8XXX9XXX · 6 holders which blocks → BOOST SUBSCRIBERCO L.L.C. 490J VILONIA AR
2022-01-05 501-518 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - AR 196F DAMASCUS AR
2021-12-08 501-498 0–9 XXXall 10 · 5 holders which blocks → BOOST SUBSCRIBERCO L.L.C. 490J LITTLEROCK AR
2021-11-09 501-491 0–9 XXXall 10 · 8 holders which blocks → BANDWIDTH.COM CLEC, LLC - AR 196F BEEBE AR
2021-10-11 501-489 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 MALVERN AR
2021-10-04 501-471 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 FERNDALE AR
2021-10-04 501-497 0–9 XXXall 10 · 8 holders which blocks → ONVOY, LLC - AR 348F CONWAY AR

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.