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 737
T-MOBILE USA, INC. 33
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
2026-06-16 737-440 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2026-06-16 737-455 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2025-10-01 737-426 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2025-07-21 737-424 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2025-06-06 737-421 0XXX1XXX2XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 ROCKDALE TX
2025-02-10 737-413 0XXX1XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 SMITHVILLE TX
2024-12-03 737-405 0XXX1XXX2XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 KYLE TX
2024-10-14 737-399 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2024-10-02 737-398 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2023-11-07 737-363 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2022-10-06 737-341 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2022-10-06 737-342 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2022-10-03 737-340 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 GEORGETOWN TX
2022-09-27 737-335 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 SAN MARCOS TX
2022-06-28 737-326 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2022-06-28 737-328 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2022-05-27 737-323 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 LEANDER TX
2022-05-27 737-324 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 LEANDER TX
2022-03-01 737-321 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 ELGIN TX
2022-02-02 737-318 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2021-09-09 737-298 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 LEANDER TX
2021-08-25 737-297 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2021-08-24 737-296 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2021-08-20 737-293 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2021-08-20 737-294 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2021-04-29 737-287 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LEANDER TX
2020-08-27 737-274 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2017-12-22 737-232 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 ELGIN TX
2017-07-20 737-221 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 SAN MARCOS TX
2017-03-29 737-217 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
2016-11-02 737-414 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 BUDA TX
2015-11-24 737-206 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
2015-11-24 737-618 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 LAMPASAS TX

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.