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 559
T-MOBILE USA, INC. 56
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
2025-08-22 559-968 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2024-08-20 559-913 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 VISALIA CA
2024-08-20 559-914 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2024-01-19 559-882 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2023-08-23 559-872 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2021-12-14 559-768 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 REEDLEY CA
2021-11-15 559-680 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2017-03-23 559-701 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2017-02-14 559-293 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2016-12-01 559-290 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2016-08-31 559-207 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2016-08-30 559-371 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2016-07-01 559-214 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2016-04-01 559-601 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 CARUTHERS CA
2015-09-11 559-491 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 HANFORD CA
2015-07-29 559-612 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2015-07-16 559-653 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 FOWLER CA
2015-07-02 559-330 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 MADERA CA
2015-06-22 559-571 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 VISALIA CA
2015-06-19 559-885 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CARUTHERS CA
2015-05-20 559-712 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2015-05-14 559-548 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2015-03-11 559-722 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2015-03-09 559-563 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 VISALIA CA
2015-03-04 559-727 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2015-02-03 559-545 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2015-01-12 559-668 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2014-11-11 559-754 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 VISALIA CA
2014-11-07 559-373 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 MADERA CA
2010-12-13 559-203 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2006-12-02 559-389 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2005-02-18 559-776 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
2002-09-19 559-813 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 FOWLER CA
2002-09-19 559-940 1XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 CLOVIS CA
2002-09-19 559-942 1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 CARUTHERS CA
2002-04-15 559-836 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 HANFORD CA
2002-02-21 559-350 1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 PORTERVL CA
2002-02-21 559-363 1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 MADERA CA
2002-01-29 559-300 1XXX which blocks → T-MOBILE USA, INC. 6529 VISALIA CA
2002-01-29 559-305 3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 REEDLEY CA
2001-12-26 559-309 1XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 HANFORD CA
2001-09-19 559-709 not yet reported which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
— 559-202 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 PORTERVL CA
— 559-213 none assigned yet which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
— 559-217 none assigned yet which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
— 559-270 none assigned yet which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
— 559-273 none assigned yet which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
— 559-306 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 PORTERVL CA
— 559-307 none assigned yet which blocks → T-MOBILE USA, INC. 6529 FRESNO CA
— 559-333 8XXX9XXX which blocks → T-MOBILE USA, INC. 6529 PORTERVL CA

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.