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 978
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 71
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
2016-09-22 978-643 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BARRE MA
2013-11-03 978-428 9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 AYER MA
2013-07-16 978-553 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HUDSON MA
2011-09-08 978-221 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LOWELL MA
2003-01-08 978-953 2XXX3XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 TOPSFIELD MA
2001-12-06 978-860 0XXX1XXX3XXX5XXX6XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LEOMINSTER MA
2001-09-21 978-702 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HAVERHILL MA
2001-07-27 978-347 1XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HAMILTON MA
2001-05-23 978-763 0–9 XXXall 10 · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HUDSON MA
2001-03-19 978-600 3XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BILLERICA MA
2001-01-09 978-517 0–9 XXXall 10 · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 AMESBURY MA
2001-01-09 978-564 1XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DANVERS MA
2001-01-09 978-610 2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CONCORD MA
— 978-202 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CONCORD MA
— 978-206 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ACTON MA
— 978-222 3XXX4XXX5XXX7XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NO READING MA
— 978-224 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SALEM MA
— 978-231 3XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GLOUCESTER MA
— 978-246 3XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MAYNARD MA
— 978-254 1XXX5XXX6XXX7XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 CONCORD MA
— 978-259 2XXX3XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LOWELL MA
— 978-278 3XXX5XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PEABODY MA
— 978-298 0XXX1XXX2XXX3XXX4XXX5XXX7XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MAYNARD MA
— 978-299 5XXX6XXX7XXX8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BEVERLY MA
— 978-334 1XXX4XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GARDNER MA
— 978-336 none assigned yet which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SALEM MA
— 978-338 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BEVERLY MA
— 978-339 2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LITTLETON MA
— 978-357 0XXX1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NO READING MA
— 978-359 1XXX4XXX7XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 TOPSFIELD MA
— 978-377 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HAVERHILL MA
— 978-379 3XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LAWRENCE MA
— 978-383 3XXX7XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 TOWNSEND MA
— 978-389 3XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BERLIN MA
— 978-414 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SALEM MA
— 978-418 3XXX4XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LOWELL MA
— 978-450 3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MAYNARD MA
— 978-477 none assigned yet which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 W NEWBURY MA
— 978-522 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 BEVERLY MA
— 978-540 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LITTLETON MA
— 978-560 3XXX7XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DANVERS MA
— 978-565 6XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SALEM MA
— 978-606 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LOWELL MA
— 978-639 0XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SUDBURY MA
— 978-642 1XXX3XXX4XXX7XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON MA
— 978-655 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 LAWRENCE MA
— 978-699 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ANDOVER MA
— 978-716 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DANVERS MA
— 978-719 0XXX2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 ANDOVER MA
— 978-737 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON MA

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.