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 657
T-MOBILE USA, INC. 74
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
2025-11-13 657-835 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2024-12-06 657-776 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2024-11-07 657-774 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ORANGE CA
2024-10-21 657-773 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2024-09-12 657-768 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2024-08-06 657-760 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2024-07-30 657-754 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 GARDEN GRV CA
2024-06-21 657-825 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2024-05-31 657-714 0XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 BUENA PARK CA
2024-05-31 657-752 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ORANGE CA
2024-05-22 657-751 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 FULLERTON CA
2024-03-27 657-731 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2023-12-05 657-710 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 GARDEN GRV CA
2023-12-04 657-709 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2023-10-10 657-705 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CYPRESS CA
2023-09-29 657-698 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 WESTMINSTR CA
2023-09-26 657-695 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2023-08-23 657-681 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 FULLERTON CA
2023-08-23 657-684 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ORANGE CA
2023-08-10 657-676 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2023-08-10 657-678 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2023-08-10 657-679 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 GARDEN GRV CA
2022-10-11 657-623 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2022-09-20 657-618 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2022-09-20 657-625 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CYPRESS CA
2022-08-12 657-615 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2022-07-22 657-612 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 GARDEN GRV CA
2022-07-14 657-608 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 ORANGE CA
2022-04-25 657-585 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2022-01-10 657-540 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2022-01-10 657-543 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2021-12-10 657-537 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SILVERADO CA
2021-11-18 657-556 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CYPRESS CA
2021-11-17 657-534 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ORANGE CA
2021-11-15 657-739 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2021-11-09 657-551 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 WESTMINSTR CA
2021-09-27 657-523 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 GARDEN GRV CA
2021-08-23 657-527 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2021-06-30 657-508 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CYPRESS CA
2021-06-09 657-502 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2021-05-19 657-505 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 ANAHEIM CA
2019-03-20 657-375 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2019-03-20 657-431 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 WESTMINSTR CA
2019-02-27 657-372 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2018-09-18 657-365 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2018-03-29 657-319 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 FULLERTON CA
2017-12-14 657-355 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 HUNTITNBCH CA
2016-11-02 657-351 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SILVERADO CA
2016-09-21 657-346 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 SANTA ANA CA
2016-08-30 657-340 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 WESTMINSTR 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.