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 317
LEVEL 3 COMMUNICATIONS, LLC - IN 35
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
2013-06-21 317-653 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
2011-11-14 317-434 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 CUMBERLAND IN
2009-05-27 317-944 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
2009-05-27 317-948 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
2008-09-09 317-495 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
2007-05-17 317-620 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 NEWPALSTIN IN
2005-05-27 317-688 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 CARMEL IN
2003-08-29 317-333 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
— 317-207 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 CHARLOTSVL IN
— 317-225 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
— 317-245 0XXX3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 ACTON IN
— 317-286 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 BROWNSBURG IN
— 317-324 5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 CARMEL IN
— 317-348 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 FISHERS IN
— 317-376 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 CICERO IN
— 317-386 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 DANVILLE IN
— 317-427 0XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 FAIRLAND IN
— 317-429 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
— 317-436 0XXX2XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 FISHERS IN
— 317-448 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 GREENFIELD IN
— 317-456 0–9 XXXall 10 · 8 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 BROWNSBURG IN
— 317-489 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
— 317-497 0XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 GREENWOOD IN
— 317-520 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 BROWNSBURG IN
— 317-522 2XXX3XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 INDIANAPLS IN
— 317-584 0XXX1XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 MOORESVL IN
— 317-623 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 NEWPALSTIN IN
— 317-645 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 NOBLESVL IN
— 317-723 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 OAKLANDON IN
— 317-754 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 PLAINFIELD IN
— 317-825 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 SHELBYVL IN
— 317-836 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 SHERIDAN IN
— 317-857 0XXX3XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 WESTNEWTON IN
— 317-942 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 ZIONSVILLE IN
— 317-973 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IN 4803 ZIONSVILLE IN

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.