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 815
T-MOBILE USA, INC. 40
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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2024-02-08 815-779 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 PLAINFIELD IL
2006-07-24 815-630 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2005-10-06 815-582 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2005-04-21 815-992 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 STREATOR IL
2004-01-07 815-616 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 FREEPORT IL
2003-07-14 815-590 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 STERLING IL
2003-07-14 815-999 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2002-09-30 815-608 1XXX2XXX3XXX4XXX5XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
2002-07-05 815-712 none assigned yet which blocks → T-MOBILE USA, INC. 6529 LA SALLE IL
2002-06-04 815-703 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
2001-09-28 815-603 not yet reported which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2001-07-24 815-791 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2001-06-25 815-793 6XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 DE KALB IL
2001-05-22 815-909 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 DE KALB IL
2001-04-27 815-814 not yet reported which blocks → T-MOBILE USA, INC. 6529 WOODSTOCK IL
2001-04-27 815-867 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 PONTIAC IL
2001-02-23 815-919 not yet reported which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2001-01-24 815-514 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2001-01-24 815-516 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-212 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-260 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-295 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 KANKAKEE IL
— 815-302 2XXX which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-378 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-405 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-482 none assigned yet which blocks → T-MOBILE USA, INC. 6529 WOODSTOCK IL
— 815-483 2XXX which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-505 not yet reported which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-509 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-519 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-530 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-540 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-549 8XXX which blocks → T-MOBILE USA, INC. 6529 KANKAKEE IL
— 815-593 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 DE KALB IL
— 815-621 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-670 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-690 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-693 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-790 none assigned yet which blocks → T-MOBILE USA, INC. 6529 WOODSTOCK IL
— 815-823 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL

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.