NumberResearch Membership · Data 09/20/2026

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 570
CORE COMMUNICATIONS, INC. - PA 62
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
2012-06-22 570-666 0–9 XXXall 10 · 6 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WILLIAMSPT PA
2009-03-31 570-652 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 TREMONT PA
2009-03-31 570-653 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 VALLEYVIEW PA
2009-03-20 570-201 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 RUSH PA
2009-03-20 570-303 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 THOMPSON PA
2009-03-20 570-361 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 SUSQUHANNA PA
2009-03-20 570-381 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 SO CANAAN PA
2009-03-20 570-530 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 ROME PA
2009-03-20 570-548 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 ST JOSEPH PA
2009-03-20 570-564 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC. - PA 3806 TIOGA PA
2009-03-20 570-566 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 PLEASANTMT PA
2009-03-20 570-571 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WAYMART PA
2009-03-20 570-667 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MUHLENBURG PA
2009-03-20 570-792 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 OVAL PA
2009-03-20 570-948 0–9 XXXall 10 · 6 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WELLSBORO PA
2009-03-19 570-464 0–9 XXXall 10 · 8 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 TURBOTVL PA
2009-03-19 570-485 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 TOWANDA PA
2009-03-19 570-533 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MONTROSE PA
2009-03-19 570-681 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 UNION DALE PA
2009-03-19 570-684 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WARREN CTR PA
2009-03-19 570-720 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 ULSTER PA
2009-03-19 570-747 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MUNCY VLY PA
2009-03-19 570-757 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MUNCY PA
2009-03-19 570-782 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 NEWMILFORD PA
2009-03-19 570-791 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WAPWALLOPN PA
2009-03-19 570-838 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WATSONTOWN PA
2009-03-19 570-870 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 TROY PA
2009-03-19 570-913 0XXX1XXX2XXX3XXX4XXX5XXX9XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 NEW ALBANY PA
2009-03-19 570-981 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 WYALUSING PA
2009-03-18 570-203 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 HUGHESVL PA
2009-03-18 570-206 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MIDLEBYCTR PA
2009-03-18 570-219 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 LAKEWINOLA PA
2009-03-18 570-248 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 LAWRENCEVL PA
2009-03-18 570-264 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MONTGOMERY PA
2009-03-18 570-304 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 LAWSVILLE PA
2009-03-18 570-305 0XXX1XXX2XXX3XXX4XXX5XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 JACKSON PA
2009-03-18 570-306 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC. - PA 3806 COVINGTON PA
2009-03-18 570-310 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 DALLAS PA
2009-03-18 570-314 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 DUSHORE PA
2009-03-18 570-349 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 EAGLESMERE PA
2009-03-18 570-375 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 LAKEWOOD PA
2009-03-18 570-410 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 HARDING PA
2009-03-18 570-438 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 BROOKLYN PA
2009-03-18 570-463 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MANSFIELD PA
2009-03-18 570-514 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MORRIS PA
2009-03-18 570-518 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 MIFFLINBG PA
2009-03-18 570-526 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 FREELAND PA
2009-03-18 570-528 0XXX1XXX2XXX3XXX4XXX5XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 HARFORD PA
2009-03-18 570-532 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 LIBERTY PA
2009-03-18 570-633 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC. - PA 3806 BENTON PA

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.