NumberResearch Membership · Data 09/21/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/21/2026

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
2001-03-30 253-273 0XXX2XXX3XXX4XXX5XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
2001-02-13 253-217 0XXX2XXX3XXX4XXX5XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-202 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
— 253-226 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-227 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-228 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-230 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-232 not yet reported which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-261 none assigned yet which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-297 9XXX which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
— 253-334 not yet reported which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-335 not yet reported which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-376 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-377 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-405 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-431 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
— 253-468 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-486 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-576 0XXX which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-640 4XXX which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
— 253-653 none assigned yet which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-831 4XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
— 253-861 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-921 9XXX which blocks → T-MOBILE USA, INC. 6529 TACOMAWVLY WA
— 253-951 none assigned yet which blocks → T-MOBILE USA, INC. 6529 AUBURN WA
— 253-961 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 TACOMA WA
— 253-988 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TACOMA WA

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/21/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.