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 319
T-MOBILE USA, INC. 39
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
2025-09-04 319-554 0XXX1XXX4XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 BRIGHTON IA
2025-03-31 319-990 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 BRIGHTON IA
2024-10-04 319-501 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 BRIGHTON IA
2024-07-18 319-496 0XXX1XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 MONTICELLO IA
2023-08-18 319-414 0XXX1XXX2XXX3XXX4XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 KEOSAUQUA IA
2022-09-16 319-508 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 KEOSAUQUA IA
2022-07-27 319-340 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
2018-08-27 319-300 0–9 XXXall 10 · 9 holders which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
2018-07-23 319-280 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 KEOSAUQUA IA
2018-03-09 319-419 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 WAVERLY IA
2018-02-12 319-412 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
2011-04-28 319-486 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
2011-03-25 319-499 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
2005-11-11 319-288 7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 KEOSAUQUA IA
2004-05-13 319-202 not yet reported which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
2002-03-07 319-241 not yet reported which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
2002-02-12 319-210 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
2001-05-30 319-473 not yet reported which blocks → T-MOBILE USA, INC. 6529 KEOKUK IA
2001-05-30 319-537 not yet reported which blocks → T-MOBILE USA, INC. 6529 MTPLEASANT IA
2001-05-30 319-561 not yet reported which blocks → T-MOBILE USA, INC. 6529 FT MADISON IA
2001-04-10 319-209 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 BURLINGTON IA
2001-02-09 319-601 2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 BURLINGTON IA
— 319-431 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
— 319-457 not yet reported which blocks → T-MOBILE USA, INC. 6529 BURLINGTON IA
— 319-471 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
— 319-493 2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
— 319-504 none assigned yet which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
— 319-509 not yet reported which blocks → T-MOBILE USA, INC. 6529 OELWEIN IA
— 319-521 not yet reported which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
— 319-533 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
— 319-548 not yet reported which blocks → T-MOBILE USA, INC. 6529 WASHINGTON IA
— 319-594 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
— 319-621 none assigned yet which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
— 319-631 7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
— 319-651 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA
— 319-821 not yet reported which blocks → T-MOBILE USA, INC. 6529 ANAMOSA IA
— 319-936 not yet reported which blocks → T-MOBILE USA, INC. 6529 IOWA CITY IA
— 319-961 not yet reported which blocks → T-MOBILE USA, INC. 6529 WATERLOO IA
— 319-981 not yet reported which blocks → T-MOBILE USA, INC. 6529 CEDAR RPDS IA

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.