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 253
T-MOBILE USA, INC. 77
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
2026-01-20 253-443 0XXX1XXX2XXX3XXX4XXX5XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2025-11-07 253-436 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2025-06-20 253-424 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2025-06-02 253-422 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2025-03-07 253-421 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2024-10-11 253-417 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2024-10-11 253-418 0XXX1XXX2XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 PUYALLUP WA
2024-05-31 253-413 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2024-03-01 253-408 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PUYALLUP WA
2024-02-22 253-407 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2024-01-12 253-406 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 GRAHAM WA
2023-08-31 253-386 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 PUYALLUP WA
2023-01-13 253-378 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2022-10-03 253-402 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2022-08-12 253-308 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2022-01-07 253-349 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2021-03-18 253-346 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2020-10-20 253-361 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
2020-10-20 253-368 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2020-07-15 253-339 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
2020-05-28 253-338 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2020-03-18 253-316 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
2020-01-14 253-317 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2018-10-23 253-527 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2016-08-11 253-287 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2016-05-12 253-257 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
2016-04-01 253-240 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2016-01-21 253-433 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2016-01-13 253-392 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
2014-09-23 253-258 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2014-01-09 253-391 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2013-12-19 253-213 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2011-08-09 253-283 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2008-02-15 253-327 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2007-10-08 253-326 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2007-10-05 253-324 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2007-05-03 253-282 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2007-03-14 253-314 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2006-07-14 253-330 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2006-06-15 253-507 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2006-06-13 253-353 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2006-01-20 253-298 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2002-06-20 253-255 3XXX4XXX which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2002-03-07 253-266 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2001-11-15 253-632 not yet reported which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
2001-11-07 253-878 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
2001-04-16 253-222 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2001-04-16 253-223 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2001-04-16 253-224 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2001-04-16 253-332 not yet reported which blocks → T-MOBILE USA, INC. 6529 AUBURN WA

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.