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 586

TELEPORT COMMUNICATIONS AMERICA, LLC - MI 22

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

Recent NPA-NXX prefix assignments
Assigned	NPA-NXX	Thousands-blocks taken (last-4 opening)	Code holder	OCN	Rate center	State
2021-12-23	586-310	0–9 XXXall 10 · 4 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	MT CLEMENS	MI
2021-08-26	586-316	0–9 XXXall 10 · 2 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	WARREN	MI
2017-11-29	586-788	0–9 XXXall 10 · 5 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	UTICA	MI
2016-01-28	586-297	0–9 XXXall 10 · 2 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	CENTERLINE	MI
2014-02-28	586-225	0–9 XXXall 10 · 3 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	CENTERLINE	MI
2006-03-06	586-232	0–9 XXXall 10 · 7 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	WASHINGTON	MI
—	586-330	0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 5 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	NEWBALTIMR	MI
—	586-331	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	ROMEO	MI
—	586-430	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	RICHMOND	MI
—	586-473	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 9 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	ARMADA	MI
—	586-580	0–9 XXXall 10 · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	UTICA	MI
—	586-646	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	NEW HAVEN	MI
—	586-697	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	WASHINGTON	MI
—	586-738	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	MT CLEMENS	MI
—	586-834	0XXX5XXX6XXX7XXX8XXX · 2 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	CENTERLINE	MI
—	586-840	4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	MT CLEMENS	MI
—	586-843	0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	UTICA	MI
—	586-859	0XXX1XXX3XXX5XXX7XXX8XXX9XXX · 3 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	ROSEVILLE	MI
—	586-864	0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	WARREN	MI
—	586-879	0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	ROSEVILLE	MI
—	586-884	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	UTICA	MI
—	586-920	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	CENTERLINE	MI

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.