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 541
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
2016-01-20 541-666 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 ALBANY OR
2014-10-16 541-930 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 MEDFORD OR
2014-08-29 541-801 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 ALBANY OR
2009-11-06 541-656 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 HERMISTON OR
2009-02-17 541-590 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 FLORENCE OR
2006-01-25 541-848 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 BEND OR
2005-09-20 541-550 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 BEND OR
2005-09-01 541-813 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 BROOKINGS OR
2002-04-17 541-351 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 NEWPORT OR
2001-12-18 541-264 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 NEWPORT OR
2001-10-23 541-292 1XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 MEDFORD OR
2001-10-23 541-295 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 GRANTSPASS OR
2001-08-17 541-314 1XXX2XXX3XXX4XXX5XXX7XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 HERMISTON OR
2001-03-22 541-212 0XXX2XXX4XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 ONTARIO OR
2001-03-22 541-228 2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
2001-03-22 541-252 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 COOS BAY OR
— 541-206 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-210 4XXX5XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 MEDFORD OR
— 541-220 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 ALBANY OR
— 541-221 4XXX5XXX6XXX7XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-230 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 CORVALLIS OR
— 541-232 none assigned yet which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-250 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 CORVALLIS OR
— 541-279 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 MADRAS OR
— 541-291 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 GRANTSPASS OR
— 541-300 1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 THE DALLES OR
— 541-301 none assigned yet which blocks → T-MOBILE USA, INC. 6529 MEDFORD OR
— 541-310 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 PENDLETON OR
— 541-321 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 JUNCTIONCY OR
— 541-337 2XXX which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-350 not yet reported which blocks → T-MOBILE USA, INC. 6529 BEND OR
— 541-380 2XXX3XXX7XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 HOOD RIVER OR
— 541-390 2XXX which blocks → T-MOBILE USA, INC. 6529 BEND OR
— 541-391 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 ROSEBURG OR
— 541-400 1XXX2XXX4XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 HOOD RIVER OR
— 541-441 3XXX4XXX5XXX6XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 GRANTSPASS OR
— 541-513 not yet reported which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-514 5XXX6XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-515 4XXX6XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-543 2XXX which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-570 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 LEBANON OR
— 541-578 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 MOSIER OR
— 541-579 2XXX8XXX which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-650 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-720 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 HERMISTON OR
— 541-731 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 EUGENE OR
— 541-777 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 MADRAS OR
— 541-788 6XXX which blocks → T-MOBILE USA, INC. 6529 BEND OR
— 541-829 2XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 CORVALLIS OR
— 541-870 none assigned yet which blocks → T-MOBILE USA, INC. 6529 EUGENE OR

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.