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 840
T-MOBILE USA, INC. 32
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
2025-11-24 840-286 9XXX which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2025-08-20 840-281 0XXX1XXX2XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 COLTON CA
2025-06-18 840-278 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2024-10-09 840-265 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2024-07-30 840-262 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2024-05-22 840-260 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 POMONA CA
2024-03-28 840-256 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 UPLAND CA
2024-03-28 840-257 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 COLTON CA
2024-03-06 840-253 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 CALIMESA CA
2024-01-19 840-251 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 REDLANDS CA
2024-01-11 840-250 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2023-12-07 840-249 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 MARSHALL CA
2023-12-05 840-248 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 FONTANA CA
2023-11-08 840-247 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 HIGHLAND CA
2023-11-01 840-246 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 ETIWANDA CA
2023-10-18 840-245 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 REDLANDS CA
2023-10-16 840-244 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 DIAMONDBAR CA
2023-10-10 840-243 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 POMONA CA
2023-07-13 840-233 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2023-06-09 840-232 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 FONTANA CA
2023-05-31 840-231 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 POMONA CA
2022-09-02 840-217 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 FONTANA CA
2022-08-12 840-213 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 REDLANDS CA
2022-08-12 840-214 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 MARSHALL CA
2022-03-01 840-216 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2022-02-28 840-215 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 HIGHLAND CA
2022-02-28 840-252 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 MENTONE CA
2021-12-14 840-210 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 FONTANA CA
2021-11-15 840-212 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CHINO CA
2021-10-28 840-207 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA
2021-09-13 840-219 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CALIMESA CA
2021-08-31 840-209 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 ARROWHEAD CA

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.