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 817
T-MOBILE USA, INC. 54
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
2021-11-18 817-883 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
2018-03-08 817-936 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
2017-12-14 817-630 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
2012-09-14 817-941 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
2001-08-23 817-894 0XXX2XXX4XXX5XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 GRANBURY TX
2001-01-18 817-681 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-401 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-501 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-521 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-538 5XXX9XXX which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-609 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 WEATHERFD TX
— 817-629 0XXX2XXX4XXX5XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 WEATHERFD TX
— 817-637 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-650 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 GRANBURY TX
— 817-657 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-658 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-683 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-689 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-690 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-691 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-703 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-705 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-706 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-714 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-715 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-721 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-723 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-726 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-729 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-743 0XXX1XXX2XXX3XXX5XXX6XXX9XXX which blocks → T-MOBILE USA, INC. 6529 NRICHLDHLS TX
— 817-749 0XXX1XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 GRAPEVINE TX
— 817-791 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-793 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-797 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-798 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-800 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-808 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-819 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-822 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-825 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-829 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-845 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-846 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-874 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-875 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-881 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-891 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-896 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-903 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-919 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX

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.